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521 cid broken camshaft dowel for timing gear . bent valves

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Lem Evans
rmcomprandy
lance flake
norm
Dave De
supervel45
maverick172
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Post  maverick172 May 17th 2023, 8:04 am

Lem Evans wrote:What lifters do you have?
they are kasse roller lifter when i bought heads i order basically everything from kasse

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Post  supervel45 May 17th 2023, 8:37 am

I don't know if up there in Canada if you guys build in the winter in cold shops or not. If you ever do I would find a way to pre heat the oil before you run the top end oil tests, as well as maybe using a thin winter oil.

It's also good to rotate the crankshaft while checking to see if it makes any difference.

When you git the valves in and check the block clearance, it would be nice to see some pictures from the bottom of the cylinder, with the head on, of what those heads look like on a 4.39" bore also.

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Post  supervel45 May 17th 2023, 9:37 am

Dave De wrote:
maverick172 wrote:well i have 60 to 70 psi hot oil pressure wot and 15too 25 at idle i could try running thicker oil. my clearnaces are . 032 on mains and .028 on rods if memory serves
Lem Evans wrote:
maverick172 wrote:521 cid  broken camshaft dowel for timing gear . bent valves - Page 3 Rock210
521 cid  broken camshaft dowel for timing gear . bent valves - Page 3 Rock110
supervel45 wrote:I saw your pictures and a little more info at the other place. It really seems like you may have had/did two problems, at the same time going, 1. Wrong cam bolt torque 2. Potential valve to block interference  and the extra 700 rpm on that last or last few passes may have come to a head together. If all 8 valves are/were clipping the block, the timing gear/pin was running on borrowed time as Lem and someone else I believe, mentioned.

You have gotten some excellent advice from both places in my opinion.

For the time being I am going to stand by my earlier posts, that you may be a special circumstance, of parts, and tolerance stack, Caused by a bore job/block casting, and head milling, ect., that was off enough, that was too close to the edge, and just did not make the cut. If I am wrong, great and one less problem for you to deal with.

Any way Check and Triple Check everything mentioned, and always be on the lookout for anything you are others may have missed.

PS:1 If the clearance is .010" I would want more personally.

PS:2 You said that engine seemed like turd from the get go. Could the exhaust valves, or some of them, ben "tweaked" a Tad from startup and not sealing good? Just something else to ponder.
here is the worst rocker arm see slight blueing on one side sorry picture little blury but you get idea . you could be correct and the exhaust valve was nicking the block the whole time and created heat possibly ? should i replace these 4 rockers?

Too much heat = not enough oiling.
Any items that have heat color should be replaced.
Your comments about oil pressure and clearances dont have anything to do with Lems comments about the heat stress on those parts. When the valves clipped the block the valve train loads were double or triple normal load. That's why the rockers look over heated which is indicative of over stress. If the intake rockers dont have that blueing appearance its obvious why they are good. If they are blue as well then I'm almost certain that oiling up isn't sufficient. At bare minimum replace all exhaust rockers and roller lifters. I like Randy's idea about clearancing the pistons for valve relief.


That's a good point on those exhaust lifters Dave. I would check them closely and be very suspect of them.

As Lem may have meant they took one good hit when the valves bent, it is unknown how much stress they took when/if the valves were clipping the block.

The Aviation Folks don't play with the roller stuff, after a shock load. I don't know how much testing the Engineers put into it when they switched, from flat tappets, but, they surely know it's not worth the liability/gamble in an Airplane.

PS: Check the pushrods for straightness. I am pretty sure you have the big and thick wall ones but, it's still a good engine building practice anyway not to overlook.

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Post  Lem Evans May 17th 2023, 10:52 am

maverick172 wrote:
Lem Evans wrote:What lifters do you have?
they are  kasse roller lifter when i bought heads i order basically everything from kasse

Please post pic of lifters...........I bet they are Morel

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Post  Lem Evans May 17th 2023, 10:55 am

How long did this damn thing run with eight bent exh. valves.?

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Post  supervel45 May 17th 2023, 11:00 am

How much Flex do the stems have at Lift? Check the Guides.Suspect

OP: Closely examine the top and bottom face edges of your exhaust valves for wear marks with a magnifying  glass and report back. Or better yet, get some good pictures of them that can be enlarged on a full screen.

Here is a nice picture, if it links, for the other guys here.

https://www.460ford.com/attachments/img_0023-jpg.95576/

This one with what appears to be multiple hits, maybe after the timing gear failure and a bent valve from piston contact.

https://www.460ford.com/attachments/img_0021-jpg.95574/

And as you can see, this exhaust valve had much less piston to valve contact. It also looks to have a very small mark on the block deck, on a full screen.

https://www.460ford.com/attachments/img_0020-jpg.95573/

^ Also note what appears to be carbon on the valve contact mark on the piston in the above photo. It may indicate the valve sticking open, somehow, and the piston slamming it closed, and the block contact was so small that the engine ran with a "tweaked" valve for a while. Just a thought.

Also Note: All Cylinders Don't have Carbon Rings on the Deck Surface or Piston Tops. Soo?

Just for refence, here is a picture of a piston, with a exhaust valve relief, for a SR71 head, it's a tight fit. I suspect it's from the large bore 598 test mule, from the location off the bore wall of the intake valve, and the location of the steam hole in the deck also? It would also likely be cut for a 1.76" valve in that case.

https://servimg.com/view/19993227/9

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Post  QtrWarrior May 17th 2023, 5:21 pm

Lem Evans wrote:How long did this damn thing run with eight bent exh. valves.?

I wouldn't think it ran too long...

Except.............
If the pin broke, it could be possible that the cam "shifted" in relation to its "pinned" position...
Possibly retarding the camshaft...That would mean all P to V clearances would change...
Possibly enough for the Ex valves to hit pistons and after being bent, then clip the cyl edge..??
Especially, if it was at high rpm...

Note...
Only one of mine is double pinned (Oakley 618) and I have never had an issue..
I use a SBC crank bolt washer and an ARP bolt, making sure it doesn't bottom out.
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Post  supervel45 May 17th 2023, 6:23 pm

^ I kinda posted part of that on the first page or maybe the second.

I went and looked at a set of my heads with the springs off, just to think it through a little more. What doesn't make sense is the exhaust valve is angled so much towards the center, from the valley or exhaust view, direction of the cylinder. The hit marks are on the edge of the piston. You would think it would bend the face of the valve up, on the side that hit, (making it further away from hitting the block), and the stem towards the center of the cylinder, away from the block.

The cam pin breaking and retarding the cam, as the under torqued bolt slipping, most certainly makes sense.

Also the cam running retarded more and more making it run like a turd.

It's a weird deal for sure.

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Post  maverick172 May 17th 2023, 7:46 pm

when i say it ran like a turd i meant ( it did not seem to have the hp i expected out of this engine infat it was not a huge differance over my iron head 501 i had in the car before .but one thing i noticed was my second lass pass i ran till end 1/4 mile and when i turned off track engine stalled which it never did that before and took me a bit to get started so my guess the pin was already broke that run and than i went back to pitss and it was only 150ft into my last and final run and let go ..
supervel45 wrote:^ I kinda posted part of that on the first page or maybe the second.

I went and looked at a set of my heads with the springs off, just to think it through a little more. What doesn't make sense is the exhaust valve is angled so much towards the center, from the valley or exhaust view, direction of the cylinder. The hit marks are on the edge of the piston. You would think it would bend the face of the valve up, on the side that hit, (making it further away from hitting the block), and the stem towards the center of the cylinder, away from the block.

The cam pin breaking and retarding the cam, as the under torqued bolt slipping, most certainly makes sense.

Also the cam running retarded more and more making it run like a turd.

It's a weird deal for sure.

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Post  supervel45 May 17th 2023, 8:55 pm

maverick172 wrote:when i say it ran like a turd i meant ( it did not seem to have the hp i expected out of this engine infat it was not a huge differance over my iron head 501 i had in the car before .but one thing i noticed was my second lass pass i ran  till end 1/4 mile and when i turned off track engine stalled which it never did that before and took me a bit to get started so my guess the pin was already broke that run and than i went back to pitss and it was only 150ft into my last and final run and let go ..
supervel45 wrote:^ I kinda posted part of that on the first page or maybe the second.

I went and looked at a set of my heads with the springs off, just to think it through a little more. What doesn't make sense is the exhaust valve is angled so much towards the center, from the valley or exhaust view, direction of the cylinder. The hit marks are on the edge of the piston. You would think it would bend the face of the valve up, on the side that hit, (making it further away from hitting the block), and the stem towards the center of the cylinder, away from the block.

The cam pin breaking and retarding the cam, as the under torqued bolt slipping, most certainly makes sense.

Also the cam running retarded more and more making it run like a turd.

It's a weird deal for sure.

On your 1/4 mile times, how did the MPH on the 501 compare to the 521?

Did the 521 loose MPH before the last pass?

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Post  maverick172 May 17th 2023, 10:07 pm

best time i run with the 521 was 11.3 1/4 and best the 501 ever did was a 10.89. but i just started playing with the 521 i think it has more in it but the has smaller cam smaller stroke smaller carb alot smaller heads alot smaller intake . same ignition system. keep in mind the 501 was running c14 when it run in the 10's. 60ft best time with 501 was a 1.6 and with 521 i got a 1.58 or something . think my 10"converter is too tight for one and i am running a 4.88 gear i have a set of 3.88 but that too high gear . i would like a 4.30 gear i think would be ideal mph was i think 121mph . car weighs 3180 without me in there
supervel45 wrote:
maverick172 wrote:when i say it ran like a turd i meant ( it did not seem to have the hp i expected out of this engine infat it was not a huge differance over my iron head 501 i had in the car before .but one thing i noticed was my second lass pass i ran  till end 1/4 mile and when i turned off track engine stalled which it never did that before and took me a bit to get started so my guess the pin was already broke that run and than i went back to pitss and it was only 150ft into my last and final run and let go ..
supervel45 wrote:^ I kinda posted part of that on the first page or maybe the second.

I went and looked at a set of my heads with the springs off, just to think it through a little more. What doesn't make sense is the exhaust valve is angled so much towards the center, from the valley or exhaust view, direction of the cylinder. The hit marks are on the edge of the piston. You would think it would bend the face of the valve up, on the side that hit, (making it further away from hitting the block), and the stem towards the center of the cylinder, away from the block.

The cam pin breaking and retarding the cam, as the under torqued bolt slipping, most certainly makes sense.

Also the cam running retarded more and more making it run like a turd.

It's a weird deal for sure.

On your 1/4 mile times,  how did the MPH on the 501 compare to the 521?

Did the 521 loose MPH before the last pass?

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Post  supervel45 May 18th 2023, 12:22 am

With the big cams we are discussing I would like to see at least 4,500 stall. I would not change the gears until you make a solid pass, and see where you cross the Traps RPM wise.

With that said, I think both of your current combos likely will reach peek Horse Power at, 6,400 to 6,600 RPM. The roller cam 521 might squeak out a couple 100 more RPM's if you are lucky.

Example: You cross the traps with your current 4.88's at 6,700 to 7,000 RPM, Call it good that's where you want to be. If it's much higher RPM's, then that go down to 4.56's.

And don't trust old and or cheap Tachometers. They do go bad and show lower RPM's sometimes. I know one mine did.

Those 33X12 inch Slicks do like a lot of gear though, to get rolling.

I thought you said you had a 12" convertor that stalled 2,800 to 3,000 or some such?

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Post  maverick172 May 18th 2023, 5:21 am

supervel45 wrote:With the big cams we are discussing I would like to see at least 4,500 stall. I would not change the gears until you make a solid pass, and see where you cross the Traps RPM wise.

With that said, I think both of your current combos likely will reach peek Horse Power at, 6,400 to 6,600 RPM. The roller cam 521 might squeak out a couple 100 more RPM's if you are lucky.

Example: You cross the traps with your current 4.88's at 6,700 to 7,000 RPM, Call it good that's where you want to be. If it's much higher RPM's, then that go down to 4.56's.

And don't trust old and or cheap Tachometers. They do go bad and show lower RPM's sometimes. I know one mine did.

Those 33X12 inch Slicks do like a lot of gear though, to get rolling.

I thought you said you had a 12" convertor that stalled 2,800 to 3,000 or some such?
they called it a 2800-3800 stall "from previous owner of car" but now that i have the engine out again i measured the converter

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Post  supervel45 May 18th 2023, 12:19 pm

On the 521 if the cam is really installed at 109 ICL, I am with Paul also. Advance it 4 degrees to 105 ICL. That will help some with your dynamic compression.

You know Nick63's P-51/521 and this SR71/533 as well as this P51/557 all making in the mid to low 700HP range have one thing in common?

https://www.429-460.com/t28022-521-with-holley-sniper-4500

https://www.motortrend.com/how-to/533-ford-big-block-westech-dyno/  

https://www.speedmaster79.com/blog/kaase-p-51-heads-on-a-1014hp-basic-big-block 754 W/O NOS

Biggish cams and cylinder heads with not a lot of compression.

All the ones with the 800 to 900 HP Dyno sheets  seem to have 12.5 to 14 to one compression.

Still yours should put you well into the 10's.


Last edited by supervel45 on May 18th 2023, 5:11 pm; edited 1 time in total (Reason for editing : had the 754HP W/O NOS on the wrong link, moved to the www.speedmaster79 link)

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Post  supervel45 May 18th 2023, 3:00 pm

Those plugs on the 521 sure looked very lean. If you ever get it back together and go to tuning I would lose that wide band and stick to the tried and true method of reading plugs and jetting for Highest MPH trough the traps.

A lot of guys don't know that on Holley jets past #60 that the hole size does not equate to the number stamped on the jet. They also don't know that sometimes 3 jets with the same number can have the same hole diameter. Case in point 80,81,82 are all listed at .093" in the old Holley Guide Books.

83=.094
84=.099
85=.100
86=.101
87=.103
88=.104
89=.104
90=.104
91=.105
92=.105
93=.105
94=.108
95=.118
96=.118
97=.125
98=.125
99=.125
100=.128

There are H and HH High Tolerance Jets also.

If you go upping or downing jet sizes it is sometimes good to skip 3 to 4 sizes to make much of a difference.

If you know the actual hole sizes, you can make a more educated choice, sometimes. Cool

PS: You need to put a vacuum gauge on the engine, to size the power valve. If your pulling 7.5hg with a 6.5hg power valve it will open just touching the gas pedal. The lowest Holley power valve made is 2.5hg. You have to be care there also. IF your engine is intake restricted, and pulls over or close to 2.5hg at WOT, it can close, and create a Lean Condition.

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Post  maverick172 May 18th 2023, 3:44 pm

supervel45 wrote:On the 521 if the cam is really installed at 109 ICL, I am with Paul also. Advance it 4 degrees to 105 ICL. That will help some with your dynamic compression.

You know Nick63's P-51/521 and this SR71/533 as well as this P51/557 all making in the mid to low 700HP range have one thing in common?

https://www.429-460.com/t28022-521-with-holley-sniper-4500

https://www.motortrend.com/how-to/533-ford-big-block-westech-dyno/  754 HP W/O NOS

https://www.speedmaster79.com/blog/kaase-p-51-heads-on-a-1014hp-basic-big-block

Biggish cams and cylinder heads with not a lot of compression.

All the ones with the 800 to 900 HP Dyno sheets  seem to have 12.5 to 14 to one compression.

Still yours should put you well into the 10's.
ya i was thinking low 10's to be honest
ya i noticed they are all higher compression i wanted pump gas friendly engine is why i choose the compression ratio

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Post  maverick172 May 18th 2023, 3:47 pm

supervel45 wrote:Those plugs on the 521 sure looked very lean. If you ever get it back together and go to tuning I would lose that wide band and stick to the tried and true method of reading plugs and jetting for Highest MPH trough the traps.

A lot of guys don't know that on Holley jets past #60 that the hole size does not equate to the number stamped on the jet. They also don't know that sometimes 3 jets with the same number can have the same hole diameter. Case in point 80,81,82 are all listed at .093" in the old Holley Guide Books.

83=.094
84=.099
85=.100
86=.101
87=.103
88=.104
89=.104
90=.104
91=.105
92=.105
93=.105
94=.108
95=.118
96=.118
97=.125
98=.125
99=.125
100=.128

There are H and HH High Tolerance Jets also.

If you go upping or downing jet sizes it is sometimes good to skip 3 to 4 sizes to make much of a difference.

If you know the actual hole sizes, you can make a more educated choice, sometimes. Cool

PS: You need to put a vacuum gauge on the engine, to size the power valve. If your pulling 7.5hg with a 6.5hg power valve it will open just touching the gas pedal. The lowest Holley power valve made is 2.5hg. You have to be care there also. IF your engine is intake restricted, and pulls over or close to 2.5hg at WOT, it can close, and create a Lean Condition.
would a small air cleaner cause the intake to restrict ? and cause it too run lean?
i have a 16" x 3" element on it all i could fit under hood scoop .
i have not tried touching the power valves i am going to have to do some reading on these i have not the clue how to tune these .. all new to me ,.

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Post  supervel45 May 18th 2023, 4:19 pm

Dirty or restricted air cleaner will make it run rich.

If you can get it to the track and cut back to back consistent passes when it is not busy, try the 16X3 a few passes, and then run a few without an air cleaner and see if it picks up. A 16X3 or 4 if it will clear should be OK on the street. If you are running big K@N oil air filter you need to carry a fire extinguisher, if you don't already.

Holley's 4150/4160's and 4500 two circuit carburetors are pretty simple to tune when you learn the basic's.

Now if you came up on fuel injection, I can see the transfer back to carburetors a little harder then the other way around.

Maybe you can download this book, it's pretty good. Mines a vintage 1980 edition.

https://see.beebooks.store/?book=1884089283

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Post  supervel45 May 18th 2023, 5:04 pm

maverick172 wrote:
supervel45 wrote:On the 521 if the cam is really installed at 109 ICL, I am with Paul also. Advance it 4 degrees to 105 ICL. That will help some with your dynamic compression.

You know Nick63's P-51/521 and this SR71/533 as well as this P51/557 all making in the mid to low 700HP range have one thing in common?

https://www.429-460.com/t28022-521-with-holley-sniper-4500

https://www.motortrend.com/how-to/533-ford-big-block-westech-dyno/  

https://www.speedmaster79.com/blog/kaase-p-51-heads-on-a-1014hp-basic-big-block 754 W/O NOS

Biggish cams and cylinder heads with not a lot of compression.

All the ones with the 800 to 900 HP Dyno sheets  seem to have 12.5 to 14 to one compression.

Still yours should put you well into the 10's.
ya i was thinking low 10's to be honest
ya i noticed they are all higher compression i wanted pump gas friendly engine is why i choose the compression ratio

You Know that 557/P51 in the second link, only had a 200HP NOS Cheater Plate to make 1014HP. That should put you into the 9's on the cheap if you don't use it a lot. You all can still get happy gas in Canada I hope?

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Post  maverick172 May 18th 2023, 5:41 pm

supervel45 wrote:Dirty or restricted air cleaner will make it run rich.

If you can get it to the track and cut back to back consistent passes when it is not busy, try the 16X3 a few passes, and then run a few without an air cleaner and see if it picks up. A 16X3 or 4 if it will clear should be OK on the street. If you are running big K@N oil air filter you need to carry a fire extinguisher, if you don't already.

Holley's 4150/4160's and 4500 two circuit carburetors are pretty simple to tune when you learn the basic's.

Now if you came up on fuel injection, I can see the transfer back to carburetors a little harder then the other way around.

Maybe you can download this book, it's pretty good. Mines a vintage 1980 edition.

https://see.beebooks.store/?book=1884089283
PS: You need to put a vacuum gauge on the engine, to size the power valve. If your pulling 7.5hg with a 6.5hg power valve it will open just touching the gas pedal. The lowest Holley power valve made is 2.5hg. You have to be care there also. IF your engine is intake restricted, and pulls over or close to 2.5hg at WOT, it can close, and create a Lean Condition.
did i read this wrong you said if you have a restricted intake can create a lean condition ? .

to me it makes sense a resticted intake system / carb cause a rich condition like a choke being on . or a restricted exhuast causes a rich condition as well. i might have to get ride of my exhaust as well . 3" pipe might be restricting in to much as well. .
ps that link shows a virus on nortons antivirus . for my computer

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Post  maverick172 May 18th 2023, 7:51 pm

so i had a chance this afternoon to tear my short block down and i am about 95% confindent the valve contacted the block deck as supervel45 had suspected . i did not get my new exhaust valves yet but i starighted a old one and mocked it up on a couple cylinders and i only have about 15 too 22 thou clearance i do not think that is enough . keep in mind these heads had .030 cut off the surface but i believe it was to close to the block and coupled with the extra 700 rpms it was enough . they might have even been tweaked before who knows . but i will be eye browing the bores like randy had said . thanks you guys for helping me troublshoot this i do not want anyone else to deal with this if you running a 4.39 bore please double check your block to exh valve clearance it is tight and for sure check if you mill your heads . cost me down time and couple g in parts and my time to tear it down . luckily the bottom end is good and i am going to add extra ring gap while i have it apart and get ready for future low boost turbo setup still want to run pump gas but want more power.

maverick172

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521 cid  broken camshaft dowel for timing gear . bent valves - Page 3 Empty Re: 521 cid broken camshaft dowel for timing gear . bent valves

Post  maverick172 May 18th 2023, 7:54 pm

Lem Evans wrote:
maverick172 wrote:
Lem Evans wrote:What lifters do you have?
they are  kasse roller lifter when i bought heads i order basically everything from kasse

Please post pic of lifters...........I bet they are Morel
i looked very carefully at them and could only find the 4 i will try get some good pics so you can see thanks

maverick172

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Post  maverick172 May 18th 2023, 7:56 pm

Lem Evans wrote:How long did this damn thing run with eight bent exh. valves.?
i am pretty sure the valves contacted the block i mocked it up this afternoon and i only have very limited clearnace and that is with the block which has a slight nick now from the valves so my guess with a untouched bore i would have 5 tho less clearnace

maverick172

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Post  supervel45 May 18th 2023, 8:56 pm

I thought of a good way to clearance that block if it comes to that.

Get a cheap 1.76" or 1.80" valve with the same size stem and make a cutter.

https://www.lindytools.com/ihpc

That way you get the perfect angle an depth. Also you need to be careful you don't cut deep enough to get where the piston ring rides in the bore.

Please post some pictures when you get the new valves from the bottom of the block, I for one would like to see them on all eight cylinders, to see, maybe, what the variance looks like.

Sorry about that link, I tried the download after I posted it. I looked for another one to no avail.

The restriction on the carburetor size or intake will cause the vacuum to be greater than the theoretical 0 at WOT.

You have to have a restriction on the top of the carburetor to cause a rich condition. Electronic fuel injection will generally compensate for it from the O2 sensor readings if it has enough range.

As far as 3" exhaust on the street it is probably a little small but, I would uncap it at the track and see how much you gain, before you change anything. I have found that the full exhaust system add low end power and just seems better on a street cruiser, even if it is a little small. It is also quieter usually also.

How much ring gap do you plan go with? From what I have found some of the big names vary on that some what.

supervel45

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Post  maverick172 May 18th 2023, 11:17 pm

ya that would be a good way to cut the "eyebrow in the bore"
i was thinking just useing a die grinder as i have a mark on my bores were the valve already touched but ya easy to over cut too or under cut ..
what you mean about carb restriction?
i am going to go .028 - .030 for the ring gap

supervel45 wrote:I thought of a good way to clearance that block if it comes to that.

Get a cheap 1.76" or 1.80" valve with the same size stem and make a cutter.

https://www.lindytools.com/ihpc

That way you get the perfect angle an depth. Also you need to be careful you don't cut deep enough to get where the piston ring rides in the bore.

Please post some pictures when you get the new valves from the bottom of the block, I for one would like to see them on all eight cylinders, to see, maybe, what the variance looks like.

Sorry about that link, I tried the download after I posted it. I looked for another one to no avail.

The restriction on the carburetor size or intake will cause the vacuum to be greater than the theoretical 0 at WOT.

You have to have a restriction on the top of the carburetor to cause a rich condition. Electronic fuel injection will generally compensate for it from the O2 sensor readings if it has enough range.

As far as 3" exhaust on the street it is probably a little small but, I would uncap it at the track and see how much you gain, before you change anything. I have found that the full exhaust system add low end power and just seems better on a street cruiser, even if it is a little small. It is also quieter usually also.

How much ring gap do you plan go with? From what I have found some of the big names vary on that some what.

maverick172

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Join date : 2022-10-16

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