CYLINDER HEAD INFO gathered by DJOHAGIN

Jon Kaase P-51 Head Flow Numbers

Courtesy of Charlie Evans

2.25 x 1.76

Out of the box

.100"=74/58
.200"=172/106
.300"=260/144
.400"=335/181
.500"=376/210
.550"=388/---
.600"=384/227
.700"=368/240
.750"=367/244
.800"=368/246

Intake bowls pocket ported

.100=74/
.200=171/
.300=260/
.400=337/
.500=384/
.600=399/
.700=403/
.750=404/
.800=407/

Out of the box but with 2.3 Intake valve and valve job changed

.100=73/
.200=149/
.300=245/
.400=328/
.500=388/
.550=409/
.600=395/
.700=377/
.750=372/
.800=369/

Fully ported with 2.3 valve with no test pipe on exhaust

.100=72/57
.200=155/112
.300=253/151
.400=336/187
.500=392/219
.600=423/242
.700=421/255
.750=421/260
.800=418/264

CJ Intake Manifold Info

Blue Thunder 2 X 4 Dual Plane Manifold

Courtesy of Charlie Evans

We did some flow testing today that I thought might be interesting to you. It was to me, because I'm always wanting to learn something. So here's the story. Lem's and my good friend, Lawes Mayfield is going to build a '64 ThunderBolt replica and wants to use a Blue Thunder 2 X 4 dual plane manifold on it's engine for the "nostalgia look". Under the hood will be a strong street/strip engine he is going to build. We all know that a good Victor single plane manifold will outflow the B.T. manifold, but the question was: By how much?

So I thought that the best way to really see the difference was to really tax or "work" the manifolds on a set of OEM, CJ style heads that really flowed good. This would be more valid than testing the manifolds on poor flowing heads that are at the bottom of the food chain. Since Lawes is going to use P-51 heads, then ported and flowed P-51 heads is what we tested the two manifolds on.

First was to baseline flow a ported P-51 head and while we did every runner, we did not test at every lift point. We tested at .400", .600" and .800" lifts. For the baseline test we used the usual radius entry, that we have made out of Lexan for the CJ port entry.

Test 1

Head Flow Numbers with radius entry.

port 1, .400=338, .600=406, .800=421
port 2, .400=341, .600=404, .800=416
port 3, .400=340, .600=409, .800=416
port 4, .400=338, .600=410, .800=421
port 5, .400=338, .600=410, .800=421
port 6, .400=340, .600=409, .800=416
port 7, .400=341, .600=404, .800=416
port 8, .400=338, .600=406, .800=421

Test 2

Head and Fully Ported FRPP H-429 Victor Dominator manifold with clay radius around the carb pad. Also, the opposite bank runners that were not being flowed were sealed off.

port&runner 1, .400=331, .600=390, .800=400
port&runner 2, .400=332, .600=393, .800=395
port&runner 3, .400=328, .600=399, .800=410
port&runner 4, .400=330, .600=395, .800=401
port&runner 5, .400=331, .600=396, .800=401
port&runner 6, .400=328, .600=396, .800=406
port&runner 7, .400=333, .600=394, .800=397
port&runner 8, .400=330, .600=391, .800=402

A well ported FRPP or Edelbrock Victor manifold does a pretty good job of keeping up with the heads, and also that they have pretty even flow distribution between all the corner and inner runners.

Test 3

Here we used Lawes Mayfield's well ported Blue Thunder 2 X 4 dual plane manifold with the CJ size port entry. We bolted the manifold to the heads and proceeded. Again the opposite bank that was not being tested was sealed of and we carefully formed a clay radius around all 8 throttle bore holes. NOTE: Runners # 1, 4, 6, & 7 are UPPER plane. Runners # 2, 3, 5 & 8 are LOWER plane

port&runner 1, .400=299, .600=350, .800=357cfm
port&runner 2, .400=312, .600=366, .800=376cfm
port&runner 3, .400=319, .600=374, .800=390cfm
port&runner 4, .400=297, .600=339, .800=354cfm
port&runner 5, .400=317, .600=370, .800=381cfm
port&runner 6, .400=307, .600=352, .800=364cfm
port&runner 7, .400=319, .600=382, .800=390cfm
port&runner 8, .400=317, .600=374, .800=386cfm

We have a problem here. We knew that the flow wouldn't be as good as the FRPP Victor H-429 manifold, however we did not expect the distribution to be off so much.

As you can see, we have a big problem with runners # 1 & 4, and a lesser problem with runner # 6. Note that they are all upper plane runners. Lawes and I talked about this and in regards to runner # 1 & 4, it seems that they can't "borrow" enough air from the adjacent runners on their plane. In other words, they can't "cross talk " very well.

The Blue Thunder manifold is a pretty good copy of the original Ford rare SK and XE experimental 2 X 4 manifolds. However, B.T. has machined their carb pad a little bit different, and there are 4 individual holes at each pad. The original Ford manifolds had a figure 8 shaped bore between carb hole #1 & #6,,, likewise between #4 & #7. I believe they knew something back then, and right now we're planning on going back and machining the carb pads this way. Let me give full credit to my friend Randy Malik for tipping me off about this.

Now then, as for what to do about runner #6 and it's poor flow, I don't know the answer yet, but we'll study it and try something. If we can get runners # 1, 4, & 6 to flow like the other five runners, I think we'll be pretty well satisified with the B. T. manifold.

What I have left for you mathematicians to do, is the subtract and calculate the differences and then also to figure the percentage drop in flow for each runner, and each manifold. Right now I've just given the test results.

P51, Al CJ / Iron CJ , PI , D0VE Flow Comparison With Intake Attached

Courtesy of Scott Johnson

I have been working on some max effort examples of the Iron CJ, PI and D0VE-C castings to run comparisons of low lift and max lift flow rates both with and with out an intake attached.

The castings were all ported by me utilising the same valve seat angles, chamber unshrouding style and all tested on the same day, same bench and with the same max ported victor dommy intake.

I was somewhat surprised at the results and thought I would share the information. The P-51 and first gen aluminum cj's are added in my last post on the thread.

Flow rates are at 28" water corrected on my flow bench. Clay radius on the intake port and on the dommy carb pad.

...............Iron CJ...PI...D0VE-C.... / Iron CJ.... PI....D0VE-C with Ported intake

Lift
.100" /....80 /86/84....................84/ 86/ 82
.200" /....165/165/169.............159/160/163
.300" /....228/232/234.............235/234/234
.400" /....278/268/274.............278/275/278
.500" /....315/300/303.............310/303/310
.600" /....342/330/327.............338/330/328
.700" /....365/345/341.............356/346/335
.800" /....385/361/350.............370/356/340

Worth noting here is the debunking of the myth that the iron CJ has poor low lift flow rates comparted to the smaller heads. When the heads are all max ported and utilise a CJ port match the flow nubmers are remarkably similar until the increasing cross sectional areas' allow additional flow at the higher lift ranges.

The intake manifold was tweeked in both the plenum area and the runner ends with the runner exits being matched to the CJ gasket excepting the floor which was left flat and raised. The final shape is a "D" with the floor elevated about .200" above the std cj port. Care was taken to minimize flow losses with the manifold attached.

The D0VE castings seem to prefer a victor match and as cast runner exits on the victor intake where the Iron CJ and PI like the D shaped cj runner exits over the as cast dove sized exits and the full CJ match.

It still amazes me how well these ancient castings flow when compared to the bow tie offerings of the same era.

At this point I feel that the D0VE heads are about the best I can do. There is just not enough port to make them bigger or better. The PI's might have a few cfm left and I am sure the iron CJ's have more as evidenced by your work and bretts work.

I was just struck by the similarity of the flow curves till about .600" or so.

I tend to agree with Brett that we need a better intake with a true CJ runner with the correct taper from plenum to exit. A super victor I guess one could call it. This would be really great for the larger stroker combos. The victors plenum seem ancient compared to the CHI intake I used for EMC 2006.

The exhaust flow rates are all very similar between the different castings. The CJ is a bit more noisey / turbulent as is the PI vs the D0VE. The PI seems to have the most refined exhaust port of all of the iron heads excepting the fuelies.

Most of the castings I do flow about 195 to 200 @ .600" lift .

The CJ and PI castings like a "D" shaped CJ match.

The D0VE heads prefer having the port entry matched to the as cast victors dove sized runner which is on the cj centers.

I have not tried doing a CJ match on a pair of TFS streets and then pairing this intake porting style with that. Might be an idea though. The best idea might be to do the "D" shaped entry on the heads and runner exits too.

I have some doubts as this would actually bell mouth the port runner at the flange which creates another set of issues with regard to loss of velocity and disruption of proper runner taper / shape from plenum to valve pocket...

I used a cley radius on the dommy flange of the intakes cloverleaf. I have an older 1050 dommy I could try and even an HVH cloverleaf dommy super sucker.

I'm curious Scott about how the heads stack up when it comes to the "spread" between the good and bad runners on the Victor intake. Are the smaller heads closer together between the good and bad or do they have a similar spread of numbers as the larger better flowing CJ??

Typically the number one runner, which is the one I tested here, is the best or second best of all of the runners with number 2 being best and number 4 being the worst with the intake manifold attached.

For those who do not know the number one and three runners on the BBF are slightly different with regard to the ports location between the pushrod pinches vs the numbers 2 and 4 runners. This makes a slight difference in flow rates when you are looking for that last bit of power.

went ahead and tested a first gen aluminum CJ and the P-51

It is worth noting that the first gen aluminum CJ or A-429 is more in line with the PI heads in both flow rate and cross section. It is not as big as an iron CJ with regard to intake port cross section at the short turn to roof.

The flow rates I have for the P-51 are for the #3 port and after yours truely bunged up the short turn costing 7 cfm peak flow. Mind you this only took .020" removed in the wrong place.


.......P-51...Al CJ...Iron CJ...PI...D0VE-C.../P-51...Al CJ... Iron CJ.... PI....D0VE-C with Ported intake

Lift
.100" /....88/79/80 /86/84....................88/81/84/ 86/ 82
.200" /....159/161/165/165/169.............170/159/159/160/163
.300" /....241/230/228/232/234.............248/229/235/234/234
.400" /....311/275/278/268/274.............309/271/278/275/278
.500" /....357/314/315/300/303.............350/301/310/303/310
.600" /....380/335/342/330/327.............364/327/338/330/328
.700" /....395/349/365/345/341.............373/342/356/346/335
.800" /....400/361/385/361/350.............381/354/370/356/340

Adding an HVH super sucker spacer (1") and holley 1050 dominator cost 8 cfm at .800", 7 cfm @ .700", 4 cfm @ .600, "4 cfm @ .500" and nothing at the lower lifts.

In my opinion I feel that the P-51's ability to move air exceeds the victors capacity to move air. This is where a better intake manifold should come into play.


I appreciate the thanks from all of you regarding this post. Charlie has posted similar figures of his work for you all and I just wanted to show case the best flow rates I have to date for these castings and help place them in some kind of order with regard to performance on a flow bench.

what are the intake port entry dimensions of your max ported TFS street head? Exhaust port exit?

The exhaust port exit stays the same as the out of the box casting is. In other words we don't go making it bigger at the flange surface. There's hardly any benefit in doing that. We 're both very much aware that you want the header gaskets and headers to fit right. If you run the TFS Street head, always use the big CJ header gasket, even though the port exit isn't that big at the bottom.

On the intake ports, what we both are doing is making the TFS Street heads fit an unported virgin Victor intake manifold, if you are going to run the Victor manifold. In doing that, we do have to open up the intake ports at the flange, in a crazy looking direction. Meaning #1 is up and to the left, #2 is up and to the right, #3 is up and to the left, & #4 is up and to the right.

Again on the intake side if you are running the Victor manifold, use the bigger CJ intake gasket.

If you are going to use the Stealth intake or some other intake with DOVE size ports and port spacing, then the intakes don't need to be opened up and you can run a stock DOVE size intake manifold gasket.

A460 Heads

"A" Style head flow numbers

Courtesy of Dave McLain

Over the last several months I've had the opportunity to flow test a few of the various "A" style heads that are now on the market. As most people know, the A-460 head was out of production for a while and during that time several other manufacturers got on the band wagon with their own version of this basic design, but with their own "improvements" along the way.

The heads tested on my flow bench were the new TFS A-460, straight out of the box, no porting or work what so ever. TFS is making a very nice cylinder head for sure and the machine work looks excellent.

The EX-514 cylinder head by Extreme Machine/Flow Technologies was tested, again out of the box with no work at all. This head made 902 horsepower on a 557 on my dyno. Bert at Flow Tech. refined the original "A" head design with smaller better flowing ports and a much improved chamber design.

I tested the EX-514 with their CNC porting package applied to the ports. They are only slightly larger after this process and it does help the numbers, particularly at high lift and on the exhaust side of the head.

Last week I got to test the head made by IDT. This head has an enormous intake port volume and this particular sample had been ported to some degree by the owner. He had been running them quite successfully on a mud racing 535 cubic inch turning a bunch of rpm. The IDT has a chamber similar to the EX-514 but has an even larger intake valve at 2.400! These heads had been run with a Victor intake attached with adapter plates which worked WAY better than they looked for some reason even with an unported intake manifold it wasn't too bad believe it or not. If IDT can ever get an intake that's actually made for their head that fits this huge port, they might work quite well on a very large engine.

A-460 style heads intake and exhaust flow.

A460
.050 36 26
.100 72 61
.200 154 126
.300 225 175
.400 279 211
.500 322 243
.600 358 269
.700 372 281
.800 383 292
.900 393 Not tested at .900 on exhaust side.

EX-514

.050 36 27
.100 73 66
.200 145 128
.300 217 176
.400 283 210
.500 334 239
.600 377 261
.700 404 278
.800 420 293
.900 419 301

EX-514 CNC

.050 38 27
.100 74 64
.200 146 128
.300 219 170
.400 287 212
.500 347 247
.600 388 282
.700 412 302
.800 434 317
.900 436 330

IDT Eliminator

.050 30 27
.100 65 63
.200 134 135
.300 203 188
.400 271 233
.500 333 265
.600 380 286
.700 393 297
.800 415 305
.900 431 313

Enjoy the numbers, remember too that ALL of these numbers were generated using the same flow bench and equipment. SO, they should provide a valid look at these cylinder heads. All of them are VERY good when compared to heads for other engines.

Can you post the numbers with a pipe on the exhaust? I lost my flow sheet.

They worked way better than they looked. I'd bet if the 535" engine had a big ass manifold on it, it may not look as good.

The adapter was just a piece of aluminum about 1 inch thick with a passage that connected the square opening to the round hole in the Victor intake. What surprised me was that the Victor intake didn't hurt the flow very much on the bench much to my surprise because the adapter was so crudely made.

I was thinking about this, the port was so enormous I guess what might have been happening was that the intake was flowing almost like it was dumping out into the atmosphere instead of a cylinder head. It could pull on the whole manifold port with no velocity gradient at the opening???

What is a gradient? The victor manifold is not perfect but much better than the credit it is given. The Ford "A" heads, I have used, have not ran good with a manifold with a lot of taper and/or short length. I used one of Price Motorsports adapter plates to do the "A"/CJ thing. Charlie did a nice job of matching the plate to the heads and manifold. It's a blown deal and has not run yet.

The velocity gradient is just how the velocity varies across the port opening at a given lift, more flow at the top, dead at the bottom etc. For instance, a DOVE-C or CJ exhaust port has a terrible velocity gradient across the port exit. It's really moving fast right at the top and it's going the wrong direction down at the bottom!!

Same with intakes, sometimes they are really moving along the floor and dead along the top, just the opposite of a typical port opening. Also, the port can have a variation from side to side too.

I don't totally understand how these factors interact when you put the intake onto the cylinder head, but somebody around here does....

So, you are using the Blue Thunder blower intake adapted to the "A" style head. I think that'll work just fine, it's going to make so much horsepower with the blower it won't make any difference!!

Sounds like the velocity probe Charlie bought! He'll be tickled to death to find out he may own a Gradient thing!

Could you be so kind to post the specs of the 557 you made 902HP with using the EX514 heads in the out-of-the-box format? I'm really curious as to intake, comp. ratio, cam, exhaust, etc......

The 557 was very basic, built using a flat top JE piston that was fly cut for the "A" style valve relief that the EX needs. The intake was the EX514 piece that was matched to their template only. The carb was a Pro Systems 1200 Dominator, it had a Cam Motion roller camshaft R2785-2962-10 was the grind number. I used Yella Terra rockers, Comp cams roller lifters and push rods. The springs, retainers, locks and valves were all from Flow Technologies and they came with the heads as their standard package.

Thanks a lot for the info. Does the EX head use the same identical piston as the A head would? What was the comp ratio on this combo?

As far as I know, yes as long as you're using a flat top piece. The chambers are shaped differently on the EX heads and they will make way over 13:1 on a flat top 557.

Using a flat top they should all be pretty darn similar, with a dome they would be unique.

Head Porting Tech

Courtesy of Charlie Evans

When Larry first contacted us about rebuilding the engine, he explained that he’d dropped or bent an exhaust valve and how he wished that he had changed valve springs before this had happened. I asked him how many dyno pulls and runs were on the engine and there weren’t enough to warrant changing springs IMO. I suggested that he hold on and that we might find another cause. So when they brought the engine down we disassembled the engine in their presence and found that all 8 exhaust valves had been hitting the sides of the cylinder walls. They had left some pretty nasty gouges in the walls and the one valve had stood all the abuse it could stand and just gave up the ghost. The problem was the builder had used the big 1.940" exhaust valve on a 4.390" bore engine (.030" over). You don’t do that with any A-460 heads, whether they are Ford Motorsport, TFS, EX 514, or Eliminator. I thought all BBF engine builders knew that, but apparently not this one. We had to cut the valve and guide out of the head and while doing so we noticed other problems. Lem commented on how bad the chambers looked and the exhaust seats were all beat up from the pounding they took with slightly bent valves not seating correctly. He also noticed that none of the intake valves had a back cut, and again that’s a no-no. So the rest of this data is about how we took a "sow’s ear" and made a "silk purse" out of it.

I cleaned the heads up with mineral spirits and wire brushed the valves to get all the carbon and oil out of the ports and off the valves in order to do a good baseline flow test. All flow tests were conducted on a 4.625" bore @ 28"H2O, on a SuperFlow SF600 with the FlowCom computer program. We use the Brzezinski Slider Plate system and a machined Lexan radiused entry for repeatability. The cfm numbers are an average of all 4 cylinders on one head.

1. INTAKES; Baseline
.100=73, .200=133.5, .300=187.3, .400=245.5, .500=305.3, .600=352.8, .700=382, .800=395.8 Total = 2075.2 cfm

Now anybody that knows anything at all about A-460 heads, knows that those numbers are very poor, especially the mid-lift numbers. So the work proceeded. The first step, while the 100+ lb. cast iron head was still on the flow bench, was to slide it over and drop out the intake valves and put a proper back cut on them. Then reinstall them and do another flow test.

2. INTAKES; Back cut
.100=75.5, .200=140, .300=201.5, .400=261.5, .500=318.5, .600=358.5, .700=382, .800=397 Total = 2134.8 cfm, = +2.8% gain.

This is a textbook example of what back cutting the intake valves will do for you. Notice that it helped the low and mid-lift flow numbers and essentially the peak numbers stayed the same. Going form 187.3 cfm to 201.5 cfm is a gain of 14 numbers at .300 and likewise a gain of 16 numbers at .400" lift, and a gain of 13 numbers at .500" lift. That was pretty easy for 20 minutes worth of work. I’m disappointed that the previous engine builder didn’t back cut the valves. Next up is some chamber work and properly unshrouding the valves.

3. INTAKES; 30 Minutes of Chamber Work
.100=77, .200=152, .300=228.5, .400=294.5, .500=345, .600=372.5, .700=386.5, .800=397 Total =2253 cfm, = +5.5% gain

In order to achieve this we worked on removing some of the mountains and valleys that were in the chamber. There are two chambers pictured that are shiny have had the work done to them. There are two other chambers where I have marked on them with a silver paint stick were I’m going to grind. Actually the other cylinder head’s chambers were a little worse than these pictured. It was like they made an unshrouding cut but that left a big ridge around the valves that needed to be worked out by hand and laid back some.

Warren Johnson once said in a Speed Reading article in National dragster that; "We want the greatest flow possible through the smallest port possible." Thus far we have gained 41 cfm @ .300" valve lift, 50 cfm @ .400" valve lift, 40 cfm @ .500, and 20 cfm @ .600. That’s impressive and we haven’t even touched the port yet! Basically as I told Larry, the air was pissed off and I’m just trying to unpiss the air and let the head flow like what it should, like what it wants to. Those of us who are head porters and really spend some time on the flow bench know that the sound will tell you a lot. Well, when I started the air sounded lazy and now it starting to sound sharp and crisp. Next up, some bowl work.

4. INTAKES; Bowl Work
.100=76, .200=151, .300=233.5, .400=302.5, .500=356.5, .600=382, .700=397, .800=412.5 Total = 2311cfm, = +2.5% gain.

In this case I did some bowl work in critical areas and a little bit of work on the short side radius. This is the first operation where I‘ve done anything before the valve seat and I really didn’t add that much volume to the runners. The bowl work did result in an increase in flow at the higher lift points and we see the port going from 397 cfm to 412.5 cfm @ .800" lift. Next up will be a little port match job at the entry.

5. INTAKES; Port Match
.100=75.5, .200=156.5, .300=235.5, .400=307.5, .500=361, .600=386.5, .700=402, .800=417.5 Total = 2342 cfm, = 1.3% gain.

The reason that we needed to do a port match at the runner entry is that the exit of the EX 514 manifold was bigger than the port entry and we had a pretty bad mismatch where the two joined. I didn’t go out to gasket size. I just wanted to get the entry slightly larger than the manifold runner exit. I do believe that this operation contributed a few cc’s of port volume though.

6. INTAKES: Summary Thus Far

I haven’t done a proper competition valve job yet, I’m still playing with the old valve job. Still to come will be the new titanium intake valves and I expect flow to increase even more once the valve job is done. I really don’t plan on porting the entire intake track because this is a 521 CID engine and Larry has expressed to me how important it is not to have the ports too big and I agree.

So here is some volume data. The unported intake runners average 327 cc’s. The runners I have worked on now average 332 cc’s. That’s a gain of 5 cc’s or 1.5%. Let’s do some math. The original baseline flow total was 2075.2 cfm. As of now the ports flow a total of 2342 cfm. That’s an increase of 12.85% in total flow. So, 12.85% minus the 1.5% gain in volume, equals an 11.35% gain in VELOCITY. That’s an overall increase of all lift points and of course the valve "sees" that twice on both the opening flank and the closing flank of the lobe. If we look at certain mid-lift points such as .400" lift, we’ve gone from 245.5 cfm to 307.5 cfm. That’s 62 cfm or an increase of 25.3% of flow. Increasing the mid-lift flow tends to help the engines have better torque and they are less "peaky". Next up are the exhaust ports.

1. EXHAUSTS; Baseline
.100=62.5, .200=96.8, .300=126.8, .400=162.8, .500=198.8, .600=233, .700=260, .800=277.3 Total = 1418 cfm

Again these numbers suck, those ports ought to be going over 300 cfm for sure. So I did some chamber work first. We generally don’t back cut the exhaust valves because it rarely helps flow.

2. EXHAUSTS; 30 Minutes of Chamber Work.
.100=63.5, .200=107, .300=140, .400=173, .500=211, .600=243.5, .700=266.5, .800=279 Total = 1483.5 cfm, = +4.6% gain.

Basically I just made the transition from the combustion chamber into the top angle of the valve job better. I got rid of the ridge that I marked with silver paint that was around the exhaust valve and had it pocketed. I took a good bit of material away from the long side. We’ll go to the bowl work next.

3. EXHAUSTS; Bowl Work.
.100=65, .200=107.5, .300=144.5, .400=187, .500=226.5, .600=259, .700=284, .800=300 Total = 1573.5 cfm, = + 6.0% gain.

The exhaust bowls like to be "blown out" in the area where they go around the guide boss. I also streamlined the guide boss some. We’d have higher flow numbers with a proper tulip titanium valve, but that’s not in the budget so right now I’m still playing with the old valves and the old valve job. I was disappointed that the previous engine builder used the Ferrea 6000 Series valves in this engine. That’s a middle grade valve and it clearly says so in the Ferrea catalog. We’ll be going with the better grade of Ferrea valve, the Competition Plus Series. This engine is a "high end" engine with a Jesel shaft rocker arm system and it will be seeing 9000 rpm, but with a middle grade valve??? Next up a little more exhaust port work and polishing.

4. EXHAUSTS; Port Work
.100=65.3, .200=110.3, .300=145.8, .400=187, .500=226.8, .600=259.3, .700=285, .800=302 Total = 1581.5 cfm, = +0.5% gain.

Not as much gain is created the further you get away from the valve seat and this is a classic example of it

5. EXHAUSTS: Summary Thus Far
We’ve gone from a total of 1418 cfm to 1581.5 cfm , so that’s an 11.53% increase in total flow. Meanwhile the exhaust ports unported volume averaged 173.5 cc’s and now the ported volume is only 175.5 cc’s. That’s an increase of only 2 cc’s or 1.1%. So, 11.5% gain in flow minus 1.1% gain in volume means we have a 10.43% increase in VELOCITY. Again I expect more when I get a proper valve job done and maybe I can post some more info later. That’s all folks!

Just to toss it out at you, I spoke to my Father today about the Ex valves and he asked me if we wanted to, and what the advantage would be to going with a Titanium Ex valve. I told him that you had not mentioned it, and that I was under the impression that it was money not well spent because of the smaller size compared to the intake...it would not really allow us to back off of the spring pressure as a whole like the intakes would. If I am incorrect feel free to guide me in.... Would we be better served extending the budget on the Titanium Ex valves, or wait and see if we are forced to buy a more expensive crank and apply the money towards that if need be. In other words, there may be enough buffer-cash to dance around the idea of adding a few dollars more to the package than we spoke about, but not enough to allow Carte Blanche.......where would the extra buy us the most.

Best Money in this case Larry, would be to get new titanium intake valves and stay with new stainless steel exhaust valves. You'll get 95% of the benefits this way. Lem and I really want to see you upgrade the crankshaft and that takes priority over titanium exhaust valves. We need to build "our house" on a solid foundation, not a sandy foundation. That's the reason for a SVO block and a billet or forged crankshaft.

Everyone remember: Professor Charlie Evans has been doing this for decades and is under no obligation to provide the forum with his exhaustive research and findings. He does so as a kind favor, kind gesture, and probably because for a very long time he has been (and therefore always will be) a teacher. I think he deserves a standing ovation for providing such a clear and insightful step-by-step explanation of what can be gained from certain "tweaks" on certain head's features.

I would like to add and say that I would go with the stainless exhaust valves instead of titanium. Titanium doesn’t like to be subjected to high heat and large spring pressure loads. I used to help a friend with his roundy-round Clevelands, and we were running titanium valves in them, and we lost two motors due to the exhaust valve heads breaking off. 9200 RPM on the gas and off the gas, then on the gas again repeatedly took its toll. We switched to premium stainless exhaust valves and never experienced another valve problem again.

To the engine builder...Shame on you! You've cost someone much hard earned money and if you are not capable of building something like this...you should've been up front with him. This build had many mistakes that should have not been so and at a premium price. I have certainly went into unchartered waters with customers...but when I do I tell them so and let the customer make the decision as to whether or not to put there faith in my abilities! Obviously we have to attempt to explore areas we have never done or we will never get better at what we do.

332cc "A" intake ports w/2.350" intake valves and less than 340cc are very moderate in size.

I appreciate it. As a side note to the other head porters and Larry, I did bite the dust and get a cast iron shard in my eye and had to go get it drilled out, then a follow-up visit the next day. I was wearing glasses, but it still got me! We all know that's part of the job with head porting, it is just a pain in the butt (eye) to put up with. My optometrist jokingly asked me how many times have I been in there to get steel out of my eyes, and I just replied "Too many!"

We're not dealers for Flow Technology and I don't know who is. I do know we can get the heads from them, and you may just want to see about getting them directly. If you are talking about the cast iron heads, you don't want to be shipping them all over the country. UPS has a surcharge for boxes over 70 lbs and these babies are 98 lbs totally bare.

Bret, if your truck pulling rules simply call for cast iron heads, then these heads are the way to go. I know your heads flow over 400 cfm also, but you've got to remember we're flowing just air on the bench. With the addition of fuel, its heavier mass and considering the total air/fuel mixture, the flow distribution pattern is going to be better with these taller intake ports than a DOOE-R head.

I find it really neat doing what you did with the numbers and the step by step of what is started with and what the end result is. I have a few pads of paper next to my bench with my chicken scratches on them. It is just like the super flow manual says pay attention to the area nearest the seat. I have lost flow doing a valve job something like 15 to 20 cfm and then found that it was were the 60 degree met the port and where the 30 degree and radius blended into the chamber. A few minutes with a cartridge roll and we were right back where we started and some times a little bit better. And all this time I thought I was doing "a good valve job". I have too seen that a little work in the right places on certain heads really seems to help. Well at least on the flow bench. A little gain here and there may not seem like much, but when you take what you started with and gain a little in 5 or 6 places it can really start to add up.

Does the same science apply to bowl work on the intake side?

On the DOOE stay away from the exhaust bowl area with a burr, and only lightly sand roll the area smooth that is closest to the intake valve. That area is dangerously thin. But, do streamline the exhaust guide area by making it wrap around the guide kind of clockwise.

On the DOOE the best intake improvements will be by widening the floor near the short turn and reshaping the short turn.

Intake Manifold Info

Why did TFS change the standard 460 water neck to the small block set up?

A little history is in order. When TFS made the old style tunnel ram manifold (that we call the John C. Holmes manifold), its water neck was traditional BBF and the thermo housing surface was horizontal, there were no clearance problems with the distributor caps because the runners were so long. As a side note the single plane manifold that carried either the TFS logo or Ford Motorsport logo had a horizontal mounting surface for the water neck also.

Then TFS redesigned the tunnel ram and made the runners shorter and the plenum bigger. This is current tunnel ram that they have on the market. With the shorter runners we had major clearance problems with the distributor cap. So the only distributor anybody could run was the MSD crank trigger or the Mallory Pro crank trigger. Because of the bigger Pro Style cap diameter with these crank triggers, there were clearance issues over there around the water neck/ thermo housing area and it was resolved by rotating things from a horizontal mounting surface to a vertical mounting surface, thus using the SBF style housing.

Later on then, when TFS totally redesigned the single plane intake into the one in the second picture, they just continued that design feature.

Old style TFS TR manifold. There were two, the "Holmes" and a unit that the runners were shorter than the new style manifold....damn near looked like a blower manifold the runners were so short.

New TFS 18-bolt heads (Charlie's Part #TFS A460-18E) links:

http://460ford.com/viewtopic.php?t=6084

http://460ford.com/viewtopic.php?t=6114

A-head Flow Numbers

Ford Motorsport A-460 Heads

Courtesy of Charlie Evans

Flow numbers for 3 sets of hand ported Motorsports A-460 heads. All exhaust are flowed WITHOUT a test pipe.

#1 set

2.30In, 1.88Ex

.100=73/62
.200=157/118
.300=237/164
.400=303/212
.500=362/252
.600=399/283
.700=410/301
.750=416/305
.800=421/310

#2 set

Lift, 2.35In, 1.88Ex

.100=75/57
.200=158/110
.300=233/156
.400=297/204
.500=356/244
.600=400/277
.700=430/300
.750=436/306
.800=423/311

#3 set

Lift, 2.40In, 1.90Ex

.100=71/57
.200=152/111
.300=239/158
.400=309/206
.500=362/256
.600=405/285
.700=437/300
.750=449/303
.800=458/306

New-Style TFS A460 91cc Head

Courtesy of Charlie Evans

2.35 x 1.88

Out of the box

.200 - 157/112 71%
.300 - 233/157 67%
.400 - 293/190 64%
.500 - 345/218 63%
.600 - 380/240 63%
.700 - 390/255 65%
.800 - 392/262 66%

Port work done

.200 - 157/128 81%
.300 - 236/164 69%
.400 - 311/209 67%
.500 - 375/265 70%
.600 - 419/297 70%
.700 - 440/318 72%
.800 - 460/331 71%

Courtesy of Charlie Evans

Ported by BJ's Cylinder Head Service and flowed by Charlie Evans

2.392 intake valve, 1.920 exhaust valve, non-tulip, without a pipe

.100=74/69
.200=153/140
.300=237/180
.400=311/224
.500=368/265
.600=416/296
.700=450/314
.800=452/327

EX514 Head

Courtesy of Charlie Evans

These are hand ported and the valve sizes are In = 2.35 and Ex = 1.900. With out test pipe.

.100=70/67
.200=148/116
.300=225/154
.400=296/190
.500=359/229
.600=405/268
.700=435/298
.750=442/308
.800=447/317
.850=457/324

C-Heads

Ford C460 Heads

C- Head flow numbers after clean-up

Courtesy of Charlie Evans

45 degree seats---2.45 intake and 1.9 exhaust valve---4.625 cylinder sleeve size---no exhaust test tube

C-heads out of the box

200 - 159/111 69%
300 - 227/150 66%
400 - 285/183 64%
500 - 327/201 61%
600 - 351/214 60%
700 - 367/221 60%
750 - 380/224 58%
800 - 380/225 59%

Bowl blend

200 - 154/111 72%
300 - 230/166 72%
400 - 306/217 70%
500 - 380/260 68%
600 - 425/270 63%
700 - 427/293 68%
750 - 418/299 71%

With out of the box performance, flow at .650 would only be around 359 cfm and with a bowl clean-up, 426 cfm. That is a 67 cfm improvement. Did the cfm improvement come from enlarging the bowl's volume, or just knocking off the flash?

The C-460 head generally has a lot of core shift from the factory. There is always a pretty major mismatch between the casting and the seat insert. So there is more than "just a little" bowl blending to do. More than tootsie roll work. These heads are not for beginners. Once you get the head straightened out like what it is supposed to be, then the flow numbers really jump up and that's where your 67 cfm comes from.

Flow Test Results: Dan Tyner's Heads

Courtesy of Charlie Evans

Saturday was visitor’s day around here and we had four guests come in from out of town. Besides the usual eating, drinking, bench racing, and hell raising, we also went to the machine shop and conducted some flow tests. We flowed an Edelbrock Performer head, a TFS A-460 head, and a FRPP C-460 head and were flowing primarily for demonstration purposes for our guests.

With Dan Tyner's C-460 heads we where able to show some classic examples of;

1. What a back cut does on an intake valve.
2. The effect of a tulip titanium exhaust valve.
3. The effect of a test pipe on exhaust flow.

1. Dan's intake ports where SuperBowl blended, without any porting up in the runner. With a 2.425" stainless steel R&D valve and NO back cut his intakes flowed;

.200=148, .300=224, .400=302, .500=367, .600=420, .700=446, .800=450 cfm.

The head/slider plate was moved over on the flow bench, the intake valve dropped out of it and a proper 30* back cut was ground on the valve. Results AFTER the back cut were;

.200=166, .300=254, .400=319, .500=386, .600=445, .700=456, .800=447 cfm.

As you can see, the results were dramatic. As much as 30 cfm more were obtained. As usual, it helped the low and mid-lift flow numbers most of all, and then at peak lift it only cost us 3 cfm. It was just a classic example of how a back cut helps, however most of the time you won't see that big of a cfm change on the heads that have a lower flowing capability.

2. The exhausts were CNC ported, however we ran a smaller than usual cutter bit in the CNC machine and therefore reduced our port size by .050" in diameter. That gave us a port that was very good, but not maxed out in size which probably helps it some in terms of heat transfer. This engine is going to be turbocharged so, we had other considerations. The flow numbers with a 1.880" stainless steel R&D valve with a nailhead shape 15* back angle were;

.200=118, .300=174, .400=230, .500=274, .600=300, .700=317, .800=330 cfm.

Again the head/slider plate was moved over and that valve was removed and one of Lem's titanium 1.880" titanium tulip shaped steep back angle valves was put in. With no other changes the tulip titanium exhaust valve gave us;

.200=129, .300=200, .400=260, .500=292, .600=317, .700=333, .800=345 cfm.

Again, a classic textbook example of what a tulip shaped exhaust valve will give you in a proper racing head. Gains all across the board and as much as 30 cfm @ .400" lift. Don't expect that much gain in a set of Edelbrock Performer heads or something along those lines.

3. For test number three we had the exhaust port flowing 355 cfm at .900" lift and threw a 2.375" diameter primary header pipe on it. It was just a short length of pipe and many companies call these "test pipes". The flow went from 355 cfm up to 378 cfm. A gain of 23 cfm, which is about the usual.

One thing I'm curious about Charlie, the numbers on the high lift for the exhaust side. Is that because of the different direction on the air flow?

The steep back angle and big radius on the titanium exhaust valves give it what we call a tulip shape. I think if it wasn't there, the air goes "turbulent" and that reduces flow. With the steep back angle the air has something to give it guidance and direction, it comes off "clean", sort of' like the trailing edge of an airplane wing or the tail end of a submarine. You've forgotten more about airplane wings than I'll ever know, so you understand.

Typically they (tulip) are not better in an OEM factory style head or so is the consensus. Charlie have you done any testing with the tulip valve in a stock head where it might appear to loose flow, but with a flow tube attached I wonder if it might show an improvement?! Yet show loss without the tube.

Do you understand what I'm trying to ask/say?

Sometimes I See Things Happen on the Flow Bench that I don't understand. Lot's of times it's like two steps forward and then one step backward.

Bret, in regards to what you said about typically a tulip valve doesn't help a stock head that much, I tend to agree. That's why in my first post up there I said; "In a proper racing head" and I also said not to expect this to happen; "In an Edelbrock head or something similar".

I have seen a tulip valve help a stock type head and I've also seen it hurt a stock type head. IMO one of the best, if not the best 1.760" exhaust valves is the one sold through Ford FRPP for their SCJ heads. They have quite a bit of back angle and are the best flowing 1.760" exhaust valves I have found, and I've spent a lot of money on R&D valves, both catalog items and custom made to my specs.

Tulip Valve reasoning, Charlie I've been thinking about this tulip valve stuff on the exhaust side and the reasons why it works in a race style head to pick up some flow but doesn't in a street head.

With the race head you've got a bowl that has some depth before the short side takes off and it makes its turn. There is also area up around the guide boss where flow can occur, in other words it flows straight up before making the turn causing most of the flow to travel parallel to the axis of the valve stem for a short distance, making the back of the valve fuller helps because it fills in an otherwise dead area and it keeps the velocity up. It doesn't matter as much at high lift because the valve is open farther and the velocity is up more in the rest of the port.

In the production style head there just isn't room for the tulip shape, more of the flow is traveling across the back of the valve at an angle to the valve stem axis due to the low short side and turn that happens almost right off of the seat. In this case the tulip valve just blocks the flow at least at mid lift where it's flowing across the back of the valve.

Dave; I Think You're Right, in fact, exactly right, as to the reason that tulip valves sometimes do not work in a stock exhaust bowl or something close to stock.

The 22 degree can help in some instances with a D00E-R. This would be with a wide port that's into the head bolt. Also the roof raised slightly. The lower and smaller the port the less you will get from my experience.

Dynamically on overlap some tell me the nail head makes more power though. That's a whole new ballgame there.

Ford C-460 Head Flow Tech Data

Courtesy of Charlie Evans

This is a summary of some interesting flow data on the last three sets of C-460 heads that have gone out the door from here. It’s a classic example of how the proper shape and also the necessary volume affect the flow curve of a cylinder head.

Set #1 was a set belonging to a truck puller in North Carolina. They had suffered an engine blow-up and came in here for welding and repair. They had already been fully ported by some other shop, and I don’t know who, but I wasn’t very impressed. When we got done with the welding, new seats and guides, and some new Manley titanium valves we did a competition valve job with Newen carbide cutters. The intakes were the standard 2.450" and the exhausts were 1.900". Although the owner didn’t ask me to, I threw them on the flow bench just to see how well the flowed. I was disappointed to say the least. The intakes (average of all 8 ports) flowed the following;

.200=160.4, .300=238.3, .400=321.6, .500=393, .600=440.1, .700=455.5, .800=431.5, .850=422.6, .900=417.3 cfm

As you can see after .700" lift these ports were all done and the heads stalled and went backward. This is a classic example of an improper shape on the short side radius, and "floor air" colliding with "roof air" in the bowl. So I called the owner and gave him the flow numbers and asked him if he wanted me to rub on them a little bit. I told him I wasn’t going to port the heads, but that I felt like they needed a little work on the short side radius. He said go ahead and I proceeded. I wish I had cc’ed the intake ports, but I forgot, so I do not know the volume of the intake ports on this set of heads. The new flow numbers are;

.200=159, .300=239.1, .400=322.9, .500=394.4, .600=443.3, .700=466.8, .800=449.3, .850=444.3, .900=439.8 cfm.

So the heads responded as I suspected they would and essentially it was a wash up until .600" lift and then we started seeing a little increase. By .700" we gained 11.3 cfm, at .800" we gained 17.8 cfm, at .850" we gained 21.7 cfm and at .900" we gained 22.5 cfm. While the flow numbers are still nothing to brag about, I am happy for the gains at the higher lifts and at least the port doesn’t stall as bad. I felt that additional major work would have been required to up them to the status of a rock & roll set of C-460 heads, and I did the above work for just $380, so I feel he got good value for his dollar. The lesson to be learned is that having the proper short side radius on the intakes, can easily pick up a set of heads 22 cfm.

Set #2 This set was done for a truck puller in Virginia. They were brand new and had our full CNC porting job on them. The intake valves were 2.450" Manley titanium again, and the exhaust were 1.880" Manley titanium. The intake port volume on these heads are right around 378 cc. The average of all eight intake ports flow is;

.200=154.8, .300=235.6, .400=312.5, .500=390, .600=451.3, .700=483.6, .800=496.4, .850=500, .900=502 cfm.

The valve job has a 45* seat, and was done with Newen cutters again. I am pleased with the flow numbers and feel like this is what a rock & roll set of C-460 heads should flow. I’ve been over this before, you can get bigger flow numbers at the high valve lifts with a 52* seat, but then the "seat life" is shortened. The things I want you to remember before we go to the next heads is that they were fully CNC ported with a 2.450" valve and the port volume was 378 cc.

Set #3 was a set of new C-460 heads that we did for a street driven turbocharged engine. In this case we did a reduced volume CNC porting program on the exhaust by using a .050" smaller diameter cutter. We also did the CNC program on the chambers and the pushrod program. The intakes were hand ported in the bowls only with special attention being paid on the short side radius. The intake valves were 2.425" (smaller) Manley titanium and the exhaust were 1.880" Manley XH - 430 Inconel. Our reasoning here was that the intake track was going to be pressurized and in the street/strip application nothing has to be maxed out according to my friend Roger Szabol in Winder, GA who races a twin turbocharged drag car. Also I wanted to keep the exhaust port walls a little thicker due to the extended heat, so that was the reasoning for the reduced volume exhaust port. Additionally, the cam was only going to be around .700" lift, so nothing had to flow really great numbers at the high valve lifts. The average of all eight intake ports was;

.200=160.3, .300=251.5, .400=332.1, .500=397.3, .600=442.5, .700=456.6, .800=453, .850=446.1, .900=439.6 cfm.

Notice that the intakes actually flowed better than Set #2, even with the smaller valve and absolutely no porting in the intake port at all, (just bowl porting) from .200" through .500" lift. The intake port volume was 332 cc (difference of 46 cc) and this is a classic example of the smaller port out flowing the bigger port at the lower valve lifts because the smaller port has increased VELOCITY! The bigger port is "lazy" at the lower lift points, but then the bigger port comes on and outflows the smaller port from .600" lift on up. The valve job was again a 45* seat and was done with the exact same Newen cutter on both heads. Also notice that from. 500" lift on up, the flow curve on these turbocharged heads and the first set of heads that I repaired is very similar in cfm. The problem is the first set is being used in a pulling truck and will see .850" or so valve lift, whereas these heads won’t need to flow at high valve lifts because of the street cam.

Lem and I have "this thing" about properly sized ports and properly sized valves for different applications. We work at it pretty hard and Lem spends a lot of time in designing custom camshafts for the racers also. The bottom line is that your head selection, your cam selection, the engine’s CID, the flow curve and many more variables should be carefully chosen when you are building your racing engine. They all should be compatible with each other.

Charlie I was just thinking about how the smaller port worked better at lower lifts, do you suppose this is because the velocity does not have to increase quite as much as the air travels from the port to the valve and seat area (it's already going faster) therefore it works better at low to medium lifts than the large port? Could this also be one of the reasons why it tends to fall off more at high lift with the valve mostly out of the picture, the velocity is now very high in the port and really drops when it reaches the cylinder? Making the port larger especially down in the bowl area might make the port work better because it makes the transition from the port to the cylinder more gradual?

Which style of port is more affected by the installation of the intake manifold, the larger one or the smaller one?? Is the larger port more forgiving if the intake tends to push the mass of the flow off center?

Volume at the high lifts is such that the air speed wants to see more area/shape over the short side and a bigger bowl. Otherwise the air becomes turbulent and "stalls" the port.

Charlie have you ever had the opportunity to test your small 332 CC head vs. the larger 378 cc intake runner on the dyno and in a drag car?

I haven't had the right "situation" present itself so I could. We're going to dyno two engines at the end of this month, but neither one of them are "C" headed engines.

I do remember you telling me that you could make a C-460 head "work" on a small 470 CID engine. Reading between the lines, I would think that would have been a small volume runner and the engine would be "working" at some very high rpm's. The small CID truck pullers that run C-460 heads work their engines between 8000 to 9000 rpm.

Charlie I've only had one 477 and it made 902 @ 7100. It had 2.35 intakes and 1.80 exhausts on a 4.440 bore. A Comp Cams cam with about .837 gross lift on the intake. The intake port was just a clean up with stock sized runner area. The same on the exhaust.

Profiler Heads

Courtesy of Charlie Evans

The web site says 524 cfm @ .900" lift and goes on to say that this can vary some depending on the valve job and etc. The set I showed Dave I had just finished, and they flow an average of 546.6 cfm @ .900" lift, and 360 cfm on the exhausts @ .900' lift without a test pipe. Of course they flow even more at .950 and 1.000" lifts. Profiler says this is a "cast as ported" head, which it is, however I assure you that if you don't port them, you're leaving some on the table. The flow numbers from another shop, for an unported set, weren't all that great.

The Profiler site also says you can run stainless steel valves, but I sure wouldn't. At this level we're talking titanium valves all the way. We're getting better flow numbers out of them (Profilers) with the 420 cc port, than either of the sets of flow numbers that E.T. Performance gives for their 400 cc port, or their bigger 440 cc port Thor heads, so I really like the heads.

I've also had my hands on a couple of different E-460 Pro Stock heads and we've flowed them. Surprisingly the 1.000" flow numbers of the Profiler heads are not too far behind the 1.000" flow numbers of the E-460 heads. The Profilers use a 2.450" intake whereas the E-460 heads have a 2.520" intake, so that's certainly a part of it. Just call me if you have any other questions.

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Intake Manifold Info For C-Heads

Single plane manifold

Has anybody ever flow a single dominator manifold for c-460 heads? I was wondering if it keeps up with the port in the heads or is it a restriction.

The manifold hurts flow 30 cfm @ .800" lift and 8 cfm @ .300" lift.

How much did the heads flow that the manifold was bolted to?

Intakes, average of all 8 ports at 28" H2O on a 4.600" bore are;

.200=157
.300=238
.400=316
.500=384
.600=431
.700=464
.800=478
.850=480.

Just wondering how restrictive the casting was, it looks to me like it would be good.

I don't feel that the intake port sees the manifold runner as much of a restriction, if any, on the "C" package. Getting the air turned into the runner entry may be the real issue. When a 1050 carburetor with bigger throttle bores was installed, the end cylinders really liked it over the stock 1050. If there was enough time, a multitude of spacer types and bigger carbs available (1150/1250) I think the flow #'s would have looked better. All of this is moot unless there is another single plane one carb manifold to compare to. Who knows what is really going on in side a running engine at WOT with the pulsing and the introduction of the heavy fluid (gas) into the mix. With its equal length runners and above the runner venturi position it's easy to see why a tunnel ram does what it does. I just did not want anyone to mistake that speck of flow data that I posted, as wisdom.

Tunnel ram

Has anyone run a tunnel ram to see how much more power can be made over a single dominator?

I talked to kaase about that hp wise. They said you would be looking a 60 to 80 hp over a single four.

What kind of issues am i going to deal with in changing from the single 4bbl manifold to Charlie Evan's adapter and the A460 tunnel ram?

There aren't any "issues" except for the deck height of YOUR block, and that holds true in regards to the proper fitment of any intake manifold. With block deck heights ranging from 10.28" to 10.32" and all points in between, it effects the proper fit of any intake manifold in regards to how high or low it sets and the proper alignment with the port.

The adaptors thick enough to fit a new SVO block with the 10.32" deck height. If your block is very much shorter, then you may need to either mill the intake surface of the heads, or mill the intake surface of your manifold, or thin the adaptor plates by milling them. That's the three options.

Also want to issue a caution that not all distributors will clear. Some will and some won't. The stock 429-460 Ford Duraspark with small cap clears just fine. Other than that, you are on your own.

Charles Hamiton is a BB Ford racer in Baltimore MD that is using a set of A-460 to C-460 adaptors. His engine builder Mark McKeown and him made a 1070 Hp with his engine and the TFS A-460 tunnel ram on C-460 heads. Mark used an MSD crank trigger and the low profile "big cap" distributor and he did have to do a good bit of machining on the thermo housing of the TFS manifold in order for the MSD low profile distributor to clear.

C-Heads on Smaller bore

Foreword

This information is mostly for individuals seeking to install C-Heads on a 4.44” bore.

Fitment of C-Heads

First and foremost, these are not a bolt on and go cylinder head. You have to deal with the some issues.

Mocking up the heads on an empty block and looking up the cylinder from underneath, the chamber is slightly larger on the front and rear sides of the cylinder. It is best to run a 4.670 cosmetic head gasket to get the head to seal to the block properly. The Felpro 1018 with the 4.500 bore leaves the stainless compression ring inside the chamber at the places mentioned above.

Ford advises that the heads be used on 4.550" bores in their paperwork, and you can see why they have to do that from their position. They have to assume most guys are just going to slap them on the engine, and not take the time to mock-up and deal with the head gasket issues and chamber overhang.

On a 4.440 bore, the exhaust valve is very close to the cylinder wall with an .800 lift camshaft and a 1.80 exhaust valve. The side clearance is only .028"! An offset dowel may help, as there is plenty of intake valve to cylinder wall clearance. The exhaust valve placement is the limiting factor on the 4.44 bore.

It is best to limit an 1.80 exhaust valve maximum on a 4.44 bore, and limit the exhaust lift to .775".

Special note: Earlier versions of the C-460 had the valves spread .030. These would not be a good choice on a 4.44 bore unless you use a 1.75 exhaust valve diameter.

Valve Angles

The valves in a C-460 head do not have any cant angle, like the factory stock heads from Ford did. Notching the cylinder wall at the top does not work. As the C-460 exhaust valve opens and makes it's way towards full lift, the valve doesn't move away from the cylinder wall. If you notched the cylinder wall, it would have to extend down the wall, the full lift of the cam.

Additional machining required

Spark plug holes have to be chased with a tap.

The 7/16" rocker arm subplate bolt holes all need to be tapped deeper. The holes are drilled deep enough, but they aren't tapped deep enough. They need a bottoming tap used on them.

The push rods rub the head. Charlie Evans has a pushrod program in order to grind intake pushrod clearance with his cnc porting service as an option because of that particular problem.

Another thing is that valve lengths can be all over the map due to core shift and machining shift. If you're shooting for a 2.100" installed height, generally 6.425" to 6.450" works for the intakes and 6.325 to 6.350" works for the exhausts. With W.W. Engineering rockers this will result in pushrod length being right around 10.100" + or - a little.

If you use all 18 bolts of the 18 head bolt pattern, call Charlie @ (270)685-4654 for the extra eight 7/16" bolts/studs. Make sure to use anti-seize on the inner four bolts/studs that screw into the alum. head in the lifter valley or they will lock up.

If you need thicker head gaskets and want Cometics or copper Hussey head gaskets, just e-mail Lem at:

lem.evans@bfevansford.com

or call the guys in the parts department (270)278-2376 and they'll get them on the way.

Clearance of bore and exhaust, their effect on exhaust flow

Running a C-Head on a 4.440" bore, doesn’t that effect the exhaust flow in a negative way being that close too the cylinder wall?? Seems to me you would not get optimum flow out of it??

I guess it would but, my car goes 9.63 @ 141, weighing in at 3895lbs. The motor is 557 cubic inches and have not worked the bugs out of it yet.

The exhaust flow would suffer some. The real question though, is how much exhaust flow is "good enough" in order to get the job done? He has answered by giving his E.T. and mph and they are good, so obviously he believes the 1.800" valve is getting the job done. I think Kaase or somebody actually said you want the exhaust valve as close as possible to the cylinder wall, especially if it means you can move the intake valve further away from the wall.

Generally, part of what makes the things work is that the exhaust valve is moved toward the cylinder wall to allow better position and size for the intake valves. One can make the valves smaller to fit lesser bores with a loss of flow/performance. Some of which may be a decent trade off in a smaller engine. At some point the ID of the seat will get too big for the small head exhaust valve, requiring seat removal and welding.

The usual exhaust valve diameter is 1.900” when the heads were designed. Ford FRPP & Ferrea has them on the shelf as a catalog item in that size. I generally use a 1.900 or a 1.880 in those heads when I do them. What he has done is run a smaller than normal exhaust valve in the head because he's using a 4.440" bore. No problem. What head porters have learned in the past few years is that we can sacrifice exhaust flow in order to get better intake flow and these engines will still run damn good. This is sort of like the Ford Kaase SCJ heads in that the E/I ratio is not a theoretical ideal 70%, but more like 60%, but the engines still run better than expected, so much for theory.

Do you have any exhaust flow numbers that you would be willing to share?

I can't find my flow sheet, but they were 274 @.700 lift with a 1.75 stainless and 45 deg seats. I know that doesn’t sound too impressive, but this 514 went 8.30 in a door car @ 2650 lbs.seems to be running pretty well. It runs on a 4.440 bore with 2.40” intake valves.

With the 1.75 valve, did you have to install a smaller ID seat to make that work?

No, I used original seats, they just hang on, it isn't awesome visually, but it works very well.

Smaller exhaust and larger intake valves

Have you tried a smaller exh. valve say 1.800 and a bigger intake 2.500 or 2.550 to help the intake side out to get it to the 530 ish cfm range? I know these heads have a strong exh port, 380+ cfm, with the 1.900 valve.

I like the 2.450" intake valve. I think the size can get too big in a hurry given the rpm range the powerglide sportsman engines live in.

In regards to using a 2.500" intake valve in c-460 heads. The seats interlock anyway and the actual 45* seat surface of the intake valve is over on the exhaust seat, so, we'd have to be pulling and welding seats up and cutting new ones. That's a lot of trouble.

Cross-section sizing, port volumes, and flow quality

Is the port cross-section of the C-Head the same size/smaller/larger than CJ heads?

The intake port cross sectional area of a C-460 head is bigger.

Do the cross-section sizes dictate the torque peak and hp rpms?

The C-460 heads have a pretty big port cross sectional area out of the box, but then so does the cast iron Cobra-Jet head. Where do most people measure this cross-section? Some measure it at the port entry, but that's not where the smallest constriction is. Generally speaking it is either at the push-rod pinch or farther down the port at the crest of the floor.

Doesn't the length of the port effect port volume?

Example: The new SCJ exhaust ports are longer than the previous CJ heads. So, if both have the exact same cross-section from the exhaust flange to valve seat, the SCJ will measure more CCs.

The port volume data would be relative to only other heads in the same family. The length enters in to the equation. For example;

Port volume of a CJ style head would be relative to all other CJ heads, with the exception of the SCJ head, because Jon pulled the valve seat up in the cylinder. Likewise the port volume of all 3 of the A-460 heads would be relative only to each other, but not to CJ's or DOVEs because they have a raised port entry and require a different intake manifold completely.

If you were to make the cross-section the same in the intake port of a SCJ head and a C-Head, would both heads show the same flow, even though the C-Head has a better angle to the bowl? And again, if you did this, wouldn't the C-Head show more volume in the intake port because it is longer?

If the minimum cross sectional area of a SCJ head and a C-460 were exactly the same, the C-460 head can be expected to flow more air due to its port being raised. Airflow does NOT like tight/small turn radiuses, therefore the higher port C-460 head will flow better.

According to the Performance Professor Jim McFarland, the better quality is something that we should all strive for and is represented by a finer atomization of the fuel droplets and a more homogenous mixture throughout the chamber. No wet spots or puddling.

If you draw the same volume of air (cfm) through a smaller cross section port the air will be moving faster. Air speed = low end torque.
Generally that would be the case to a large degree, but cam and manifolding plays their part also.

You stated that the intake port cross sectional area of a C-460 head is bigger than any cast iron head, so low and mid-range torque would be hurt a lot on a 460 cubic inch engine. Kind of like the street Boss 429? Is this correct, or does the port shape help to overcome this?

It's possible that the head may be too big for a 460 CID engine, and that the ports may be lazy unless you really twist the engine tight. I don't think it would make a responsive street head. In that respect it would be like the Boss 429 you mentioned. Still, on the other hand, it should do better than the Boss 429 because of the better port design. The port entry is raised much higher than the Boss 429. This entry is generally measured by the height of the port's floor above the deck surface, or relative to the deck surface. The original Boss 429 head's port floor was about 5/8" above the deck surface and the C-460's port floor is about 2" above the deck surface. So you can see it's a raised port. As better heads are developed, you're always going to see the ports being raised higher and higher. Thus the overall height of the head becomes taller and taller.

Flat-Tappet, C-Head, 4.40" Bore Engine

To partially answer your question about lower rpm performance from a C-460 motor, here are the dyno results for our C-460 engine when it had an Ultradyne flat tappet cam, 4.4 bore, 4.2 stroke, 11:1 CR, 1X4bbl, almost no head work. These numbers came with 110 octane and 36 degrees total advance, we were able to run it on 92 with either 32 or 34 degrees (can't remember). Unfortunately, I do not have the data from 92 octane test (this was several years ago). I think all we did was check to see if it was feasible. We typically ran this motor with a 50/50 mix of 92 and 110. Cam specs (same for both intake and exhaust): 0.663" lift with 1.8 rockers, 259 duration @ 0.050, 292 duration @ 0.020, 112 lobe separation.

RPM HP Tq.
4500 580.9 678
4600 593.4 677.5
4700 610.5 682.2
4800 627 686
4900 640.1 686.1
5000 664.6 698.1
5100 676.9 697.1
5200 688.9 695.8
5300 704.6 698.2
5400 714.5 694.9
5500 727.5 694.7
5600 739.7 693.7
5700 753.2 694
5800 754.2 682.9
5900 758.3 675
6000 762 667
6100 766.1 659.6
6200 770.4 652.6
6300 785.3 654.7
6400 796.2 653.4
6500 797.2 644.1
6600 Peak 802.5 638.6

Can you give some more details on that build?

The numbers came from the dyno at Huffaker Engineering. I never raced it with 92 octane, just did a dyno test. It was a stock block and it had cracked cylinders by the end of each year I ran it. We also had symptoms of valve float on the cylinder walls. We probably ran it for too long on a set of valve springs. I was using the engine for road racing. It might have gone for quite a long time in a street/strip application.

I'm not sure how much more detail I can muster. I wish I could remember exactly how big the valves were. It had aluminum rods, I think it was an LA Crank, it had a wet sump, C-460 manifold, and 4-into-1 headers.

Part of the reason for using C heads in the stock block, flat tappet application was upgrade potential. Harold's view was that a relatively unimproved C head was still quite good compared to other alternatives and that while expensive, the valve train would support endurance needs.

Having implemented some of the upgrade potential, such as port optimization, a roller cam, a bit more compression (now 12.6:1), a 4.56" bore (different block) and a 4.25" stroke, the engine now makes over 950hp through the mufflers at a still reasonable/sustainable 6,700 rpm.

What size are the valves in the 4.560" bore?

I believe they are 2.44/1.87

Performance of C-Heads from 2 members

First let me explain my reasoning for using the C heads on the 557. They have pretty decent numbers right out of the box. They take a little work but what doesn't? I was looking more at a head that would work decent but still let me use it on a bigger cubic inch motor at a later date, kind of an investment so to speak. Small chambers and shaft rockers in which also was factored in for future use. It was a little pricy but now I have them.

The heads are bowl blended, short turn worked a little on the intake side, and I matched the entry to the gasket for about 1 1/2" in, catridged rolled the entire port and removed very little casting flash to make them appear symmetrical to the eye. Exhaust side has a bowl blend and cartridge roll finish all the way out.

Heads were put on a flow bench at Kuntz & Co. This is where the valves were installed and the valve job was performed. They did no port work at all with the exception of cc-ing the chamber and blending the seat to the chamber.

Flow numbers as follows;

Intake: 2.400 dia. @ 28" water

.300 - 245.85
.400 - 323.18
.500 - 383.52
.600 - 422.86
.650 - 440.00
.700 - 451.35
.800 - 468.78

Exhaust: 1.800 dia. @ 28" water

.300 - 161.35
.400 - 194.00
.500 - 229.75
.600 - 290.05
.650 - 298.98
.700 - 309.63
.800 - 318.19

If they are flowed by Jim Kuntz, you can be sure the info is accurate. Based on my testing of the C-460 heads and comparing flow numbers, I believe your info is accurate. These are good flow numbers relative to your application on the 557 CID engine. I suspect that the most important thing you did on the intake side was to lay back the short side radius some. Out of the box these heads tend to stall around .600" -.700" lift with just a bowl blend.

They are on a 557 with a single four intake and a 1250 dominator, flat top pistons, light tension rings with a vacuum pump, 6.800 steel rods and a billet 4.500 crank. Roller cam with a 114 lobe separation and 278* / 292* @ .050 with a lift in the upper .700 lift bracket. Home built step headers 33" long, 2" - 2 1/8" - 2 1/4" into a 4" collector with an X pipe and mufflers that are also 4". This is in a 65 Galaxie that weighs 3895lbs with me in it. I run a C-4 with a 10" converter, 4.86 gears, and 31 X 10.5W slicks. Car has gone some 9.63's @ 141 with the 1250 on it. 60's in the 1.35 to 1.36 range off the footbrake.

I don't think he has any more work in putting his C-heads on his 557 then I had putting SCJ heads on my 512 as far as machine work and little nuances. If I had a ‘65 Galaxie with the engine bay he has, I'd have C-heads. Their physical size (both width and height) is large by extra large. I think his results in his heavy car speak volumes on what these heads are capable of on a relatively low-rpm/high torque engine.

Something I think that helps too are these cylinder heads are sufficient as well as efficient. Meaning they are big enough to get the job done but also are a proven power maker on just about anything even without a lot of work done to them.

I have learned a lot from this forum. If I would have gone with the A-head and had them cnc programmed I feel that I would have had a head comparable to what I have now but minus the titanium valves and shaft rocker system. Price wise I actually did better considering I have an upgradeable baseline C head right now. I wanted a car that would turn heads and run a good number yet still retain all its glass and interior. I have done what everyone else still thinks is impossible.

C-Head Flow Numbers

Ford C460 Head

Courtesy of Charlie Evans

45-degree seats
2.45 x 1.90

Out of the box

.200 - 159/111 69%
.300 - 227/150 66%
.400 - 285/183 64%
.500 - 327/201 61%
.600 - 351/214 60%
.700 - 367/221 60%
.750 - 380/224 58%
.800 - 380/225 59%

Bowl blend

.200 - 154/111 72%
.300 - 230/166 72%
.400 - 306/217 70%
.500 - 380/260 68%
.600 - 425/270 63%
.700 - 427/293 68%
.750 - 418/299 71%
.800 - 413/302 73%

Hand ported

.200 - 158/125 79%
.300 - 238/164 68%
.400 - 316/212 67%
.500 - 384/270 70%
.600 - 431/295 68%
.700 - 464/315 67%
.750 - 476/320 67%
.800 - 480/325 67%

CNC program

.200 - 160/130 81%
.300 - 245/170 69%
.400 - 327/210 64%
.500 - 400/280 70%
.600 - 450/315 70%
.700 - 478/340 71%
.750 - 490/347 70%
.800 - 500/355 71%


Pro-Filer Heads

Courtesy of Charlie Evans

Through a "friend of a friend" a set of Profilers recently came across my workbench. These heads had been prepped by Bennett Racing in Alabama. As you know they are high end heads and supposedly one of the advantages of these heads is that they are "cast as ported". Bennett had done a good bowl blend and the valve job. The intakes were 2.400" with a 52* seat and corresponding back cuts & etc. The exhaust were 1.900" with a 55* seat. The heads were flowed at 28" H2O by Bennett. These are their flow numbers. The exhaust were flowed WITHOUT a test pipe.

.200=166/115
.300=243/164
.400=304/210
.500=356/244
.600=410/272
.700=462/289
.800=486/305
.900=504/319

Ford B-460 Pro Stock Bastard Heads

History Of The Bastard Head

Courtesy of Paul Kane

First to clarify, we are not talking about the traditional Ford Motorsport B head.

We are talking about a little known, small production run cylinder head that, as I understand it, was never sold through Ford Motorsport. Yes, it was assigned a Ford Motorsport part number (and put in the B460 part number family) but is not the small port B head that everyone is thinking about.

We are talking about a head that was so far ahead of it's time (cast back in 1990-ish) that only in recent years can other wedge heads rival its max effort flow numbers. Only a handful were ever produced, as the Smith brothers were playing with the mold and final dimensional variations every few castings. I believe that Ford gave Rick & Mike the go-ahead to R&D their ideas and therefore assigned this "cylinder head R&D project" a part number, but the heads were never formally released/sold through Ford Motorsport. Somebody correct me if I am mistaken anywhere. Good thing, because even though they all have the same number, there are differences in the groups of heads that were created.

The pair that I have are cast with the Pontiac valve covers.

Closest thing to these heads today is the Thor head.

Of special note, the roof of the exhaust ports are higher than the head bolt heads. They have seriously raised ports!

A link a picture of the heads:

http://460ford.com/viewtopic.php?t=17836

Courtesy of Charlie Evans

Here's what I know about the Bastard Pro Stock heads, but Lem knows more than what I do, so he can correct anything I say in error.

Mike and Rick Smith were the founders of TFS and my three pages of notes are directly from Rick Smith.

1. Starting midway. There were 4,000 to 5,000 Ford Motorsports A-460 heads made. They were "detuned" from the original TFS A-460 heads. The Ford Motorsports heads had a reduced bowl volume (10%) and more material under the short side radius. They had intake angles of 13* X 5.2* and exhaust angles of 9.5* X 5.2*. The seat for the intake valve allowed you to go down to a 2.190" intake valve.

2. Next came the B-460 head which was a small intake runner volume head. These heads are sometimes referred to as the "truck head". There was a matching small runner intake manifold. Maybe 500 heads were produced.

3. I'm skipping over the Stage 5 head (10 sets made), the Stage 6 head ( 2 sets made), and the Stage 7 head (10 sets made) and going on to the Stage 8 head, which are the two sets pictured above in this thread.

4. The Stage 8 Bastard Pro Stock heads like what Mustangracer2 (Andy) and Paul Kane have. They are pictured above. Known as the 17* head, they have intake angles of 17* X 6* and exhaust angles of 4* X 3*. They took a Pontiac Pro Stock style valve cover (as did all the rest of the Bastard Pro Stock heads), and had steel sleeves in the head bolts on the intake side. There were about 10 sets made. Lem had them done in the late 80's if my information is correct. He ran them in the Pro Stock class (500 C.I.D.)in drag boat racing and set a national record. Years later in 2002 we ran them again and I flowed them at that time. They had a 2.380" intake valve and a 1.880" exhaust valve.

From April 2002, Intake numbers are;
.200=159, .300=250, .400=335, .500=405, .600=447, .700=473, .800=484, .850=487, .900=490 cfm. These did NOT have the steep valve angles.

Exhausts numbers are;
.200=130, .300=178, .400=226, .500=272, .600=313, .700=338, .800=353, .850=358, .900=363 cfm. That is WITHOUT a test pipe. Again these do not have the steep valve angles.

As you can tell from Paul's picture, they have an 87-88 cc chamber.

5. Stage 9 Bastard Pro Stock heads were the same as the above 17* head, but they added the extra lugs for the 18 bolt pattern. So this was the first introduction of the 18 bolt pattern. They were not drilled however. There were a couple of solid sets made for Keith Dyer in Texas who ran blown alcohol. In total there were about 5 or 6 sets made, the rest having water jackets.

6. Next up, Steve Schmidt in Indy advised that they change the valve angles and try a 14* X 4* intake and a 4* X 3* exhaust, which they did. These heads (Stage 10) still had the long outside head bolt boss, and tall exhaust port. They were more of an oval shaped port, and intake #1 was turned/leaned towards intake #2, likewise intake # 4 was turned/leaned towards intake #3. They were grouping the intake ports for better carb alignment under the two Dominators. I don't know how many sets were made.

7. Stage 11 was the same as above, but they tried a tunnel port version, with the pushrod tube in the intake. One set was made.

8. Stage 12, called the "Sobczak head" by Rick, because Dave Sobczak set NHRA records with this head. This is the head pictured by Lem in the above photos and is the last generation of the TFS Bastard Pro Stock heads. The valve angles were changed again, and they used an intake angle of 11* X - 1.5*, (yes, that's negative 1.5* cant), and the exhaust angle was 3* X 4*. The exhaust face was cut at the outside edge of the valve cover and had the low outside bolts. The bolt boss is 2.5" tall. This design was to improve the manifold alignment and to duplicate the "good" port on the Eicke heads. They made about 6 sets. One set for Bob Glidden which was later on bought back, one for Steve Schmidt, one for your man Tim,,,Ralph Ferra in Mass., one set for Subczak, which later on Bryan Matthews in south Georgia bought that entire engine. As of now Lem has a set and Rick thinks there's still a set at Summit/TFS. The drawings are at TFS also. Remember that all this work was done years ago, and IMO the heads were ahead of their time.

What made the bastard Pro Stock Ford head obsolete?

Back in the late 70's & early 80's, we didn't have much for the BB Ford racers, in the cylinder head department, other than the Ford Boss 429 Hemi head and derivatives of it. That's why I often say that we've never had it so good, in terms of cylinder head choices, as we do now.

Then along in the early 80's came Mike and Rick Smith, who founded Trick Flow Specialities. They bleed Ford Blue period! They developed the A-460 heads and then versions of the A-460 heads evolved into the bastard Pro Stock heads we've been speaking of. We need to be thankful for the Smith brothers efforts. As Lem said, it was in the late 80's and early 90's that the development of the bastard Pro Stock heads took place. In addition to hard work on the Smith brothers part, guys like Louie Sauli, Lem Evans & Steve Schmidt all chipped in and helped out in one fashion or another.

Bob Glidden was Rick's idol and Rick was hopeful that one day Bob would be running a set of his pro stock heads. When the opportunity came Bob got a set, but refused to run them. What can I say, other than politics, ego, money and maybe some other factors might have influenced his decision. If you remember, in the late 80's/early 90's Thunderbird days, there were egos/issues/politics in regards to Bob G. vs. Larry Widmer, parts offerings in the SVO catalog and Hemi heads etc. You can Google search Endyn and "The Old One" for info on that.

One thing I forgot to mention about the bastard Pro Stock heads, is that you have to assemble the spring package after you bolt the heads on the engine. In other words like the Olds pro stock head, and other heads with a lot of cant angle, the intake valve spring leans out and over the top row of head bolts, so the deal is you put the valves in with a small diameter light tension spring, then bolt the heads on, then put air into the cylinders and proceed to install your real valve springs.

In regards to the bore centerline dimensions. The BB Mopar is 4.800", the BB Chevy is 4.840" and the 429/460 BB Ford is 4.900" (Note; Fords had this 4.900" dimension all the way back to the 383/430/462 MEL engines). In the early 90's Mopar figured out they could bigger valves in their wedge headed pro stock engines, if they put the heads on a bigger bore space engine. They also realized a bunch of other advantages that the GM block had over their true Mopar blocks, thus they started borrowing GM's DRCE Gen 1 block and assigned it a part number.

Then GM realized the advantages of the Ford dimension of 4.900" so they cast the DRCE Gen 2 block and used a 4.900" bore centerline spacing along with other things like the +.400" raised cam, Ford roller cam bearings etc. Then NHRA said whoa, we're stopping here at 4.900" because Ford was already 5.000" with Jon Kaase's IHRA engines and they asked NHRA for permission to go to 5.000", which they did not get.

The TFS/Ford Motorsports bastard Pro Stock wedge head was not outdated by GM/Olds/DRCE at this time (mid 90's). IMO the Olds head is related to it. The answer is, more or less that no one continued to develop things. It was a money losing project for Rick and Mike Smith, and it needed the full support of Bob Glidden and also Ford. In the end things just sorted died a slow death.