Cylinder Head Flow Thread

[dfree383]

Heres the flows from a set of TFS A460's Charlie did up for me and a Set of ported Old Style Ford Motorsports A picked up last Year.

Both where flowed a 28" with a 4.625 Bore and no pipe.

Heads are Old Style Motorsport A460
Intake Valve = Titanium 2.40 11/32 stem with Back Cut
Exhaust Valve = SS 1.90 11/32 stem
Average Chamber Volumn is around 78cc's

Flow I / E

.100 75.6 / 59.0
.200 151.6 / 120.0
.300 234.7 / 158.4
.400 310.0 / 197.3
.500 368.3 / 235.4
.600 413.1 / 267.0
.700 437.0 / 291.6
.750 442.8 / 303.6
.800 445.0 / 313.8


CNC Ported (C. Evans) New Style TFS A460's average of all 8 ports.

28" H2O, No Exhaust Pipe, on a 4.625 bore, 2.35 Rev SS Intake, 1.88 Ferrea SS Exhaust, Flowed on a SF600 Bench

Intakes / Exhaust

.100 74 / 58
.200 161 / 118
.300 245 / 165
.400 315 / 200
.500 375 / 235
.600 408 / 267
.700 439 / 294
.750 451 / 303
.800 465 / 312

[RapidRuss]

Pretty Damn close accept at .800" lift !! I would have thought there would have been a bigger difference ? and how much do the new A460 Big valve 18 bolt heads go for ? + the CNC work..

[dfree383]

Give Charlie a ring he can fill you in on the latest pricing

[RapidRuss]

Yeah Dave I'll have to do that..Its been awhile since I've talked to Charlie or Lem..

[schmitty]

I'd say there is almost 50hp worth of difference there across the board. The old style go flat at .600 and up, where the new style keep on going to .800. Nice comparo there Mr. Dave and Mr. Evans.

[David Cole]

Just thought I would throw mine in here. It shows the difference between the CNC'd/hand finished A460's of Dave's and the non CNC, hand port only heads for a little smaller budget.

New Style A460 hand ported by Charlie Evans. 10 bolt heads.
4.625 bore, no exh pipe, 28" H2O, 2.35"/1.88" stainless valves (valves oem to heads)

Averages
Intakes / Exhaust

.100 73 / 58
.200 153 / 110
.300 230 / 153
.400 294 / 190
.500 352 / 223
.600 396 / 256
.700 432 / 286
.750 443 / 298
.800 451 / 308

[72mav]

Dont mean to hi-jack. But we are kind of here anyway.
Lately Charlie has been doing wonders with the p-51's. Am really surprised to see them on one of the bigger motors like KY's 562.In the past this would probably be a A-head candidate. Even Blake is going to them. How large could theese heads go on a GOOD large displacement roller motor?There has to be a SWEET spot or limit to everything.
Reason i ask is Im looking at building a low-budget 521 right now. Thinking of going P-51 on them. Then later when finances get better build a bigger/better motor and use/ upgrade the P-51's on that.
605 anyone?????, seems the stock size chamber would give problems with the large bore and just be too small on a 605? Thanks.
Regards.
Al

[KY JELLY]

I am not an expert on the cubic inch thing , but I would like to comment here. I don't think that a well prepped set of A heads will fall victim on the dyno to P-51's .

You need to look at what you are running your engine in though. A light weight door car or dragster is very sensitive to small weight changes , that 60-70 lb difference in the head/intake weights will require at least 75 more hp just to be even imo.

[IDT-572]

The P-51's would IMHO be a good choice on a 521 as they work really well on a smaller bore , the intake valve is moved farther away from the cylinder bore. I flow test on a SF 600 here close by, but it has a smaller bore insert than Mike Phillips SF 600 with a 4.625, I think the one here is a 4.500.

The flow numbers between standard valve location heads or a good 12- 15 cfm different (less on the stock valve location heads on the smaller bore). Kasse SCJ'S and P-51's flow the same on both benches.

[72mav]

So whats the heavier head?,the A or P-51? Didnt know there was that much difference in weight, Which would matter of course.

Thanks for the input guys.
Regards.
Al

[IDT-572]

The A head is the heavier of the two buy a good bit, also the manifold is bigger and heavier. I could weigh both at work Monday and tell you for sure , but the heads will be bear ,

[72mav]

Thanks Blake.
Keep it right here
Al

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