408c CR Iron vs Aluminum Heads

[basstrix]

I'm preparing to order a stroker kit and wanting to understand where I'll end up on static CR with iron vs aluminum. The default CR pistons that TMeyer sells are either flat tops or 20cc dish. With a zero deck and 64cc chambers, that comes out right at 10:1.

I'd like to start with my iron cc heads (63-64cc) and have an option to switch up to aluminum and take advantage of their ability to withstand a bit more CR before detonating.

Aluminum head offerings seem to be 60, 62, and 72cc. Besides Trick Flow and Edelbrock, what else is out there (besides the old high port race stuff)? Chi? Speedmaster scares me....I've seen what a dropped valve seat does....and guides slipping doesn't interest me either.

For those who built for pump gas (91-93 octane), I'd like to see what others have done for piston choice, in terms of dish/dome volume, combustion chamber volume, and head material. I understand that dynamic CR is the major factor in what will run on pump gas, just trying to gauge what's been done in case I'm missing something.

...and then there's this timing set keyway issue that just popped up.

 

[Sheriff41]

CHI and SCM from Australia.

 

[turtle5353]

I am running AFD heads from Australia. With a Scat 408 Stroker kit. I run 93 pump gas and close to 600 hp out of my combo.

 

[basstrix]

I am running AFD heads from Australia. With a Scat 408 Stroker kit. I run 93 pump gas and close to 600 hp out of my combo.

What are your static and dynamic CR numbers? Are the AFD head compatible with standard intakes and headers? What about valve geometry? Do you need pistons specific to their geometry?

 

[c9zx]

Iron 4V CC heads 69cc, SCR 9.7, DCR 7.7, Mahle pistons 20cc dish, 91 octane, no detonation. I should have used more compression and more cam lift. It still made 529 BHP and 496 BTQ. If I were to pick an aftermarket head today it would be the CNC ported TFS. The CHI and SCM heads are great but ,WAY over priced, especially in light of the current exchange rate. Again, just my opinion. If picking a piston today it would be Auto-Tec. Excellent quality and up-grades are reasonably priced. Chuck

 

[turtle5353]

What are your static and dynamic CR numbers? Are the AFD head compatible with standard intakes and headers? What about valve geometry? Do you need pistons specific to their geometry?

We built this motor about 10 years ago. If I remember correctly compression was around 10.5 I am running a Torker II intake and my engine builder did some epoxy work to the runners for a better transition into heads. I think I’m running a custom comp cam and morel hydraulic roller lifters and Harland sharp roller rockers. I am running the piston that came with the scat kit. Icon pistons if I remember correctly. No issue with geometry.
Here is the Stroker kit from summit.
https://www.summitracing.com/parts/sca-1-94270be/media/images/make/ford

 

[Cleveland Crush]

I'm preparing to order a stroker kit and wanting to understand where I'll end up on static CR with iron vs aluminum. The default CR pistons that TMeyer sells are either flat tops or 20cc dish. With a zero deck and 64cc chambers, that comes out right at 10:1.

I'd like to start with my iron cc heads (63-64cc) and have an option to switch up to aluminum and take advantage of their ability to withstand a bit more CR before detonating.

Aluminum head offerings seem to be 60, 62, and 72cc. Besides Trick Flow and Edelbrock, what else is out there (besides the old high port race stuff)? Chi? Speedmaster scares me....I've seen what a dropped valve seat does....and guides slipping doesn't interest me either.

For those who built for pump gas (91-93 octane), I'd like to see what others have done for piston choice, in terms of dish/dome volume, combustion chamber volume, and head material. I understand that dynamic CR is the major factor in what will run on pump gas, just trying to gauge what's been done in case I'm missing something.

...and then there's this timing set keyway issue that just popped up.

427c cid, CHI 3V 67cc with AutoTec pistons 13cc dish and .015" squish (quench) clearance. 10.75 static compression with 195 psi cranking compression. 695 flywheel hp. 93 octane pump gas no problem.

 

[basstrix]

427c cid, CHI 3V 67cc with AutoTec pistons 13cc dish and .015" squish (quench) clearance. 10.75 static compression with 195 psi cranking compression. 695 flywheel hp. 93 octane pump gas no problem.

Impressive! What intake are you running with the 3V heads? Are you able to run stock pattern headers? Any clearance issues with headers? I don't know anything about the 3V's but have read that the raised exhaust ports can cause fitment issues.

Edit: Oh, and what is bore x stroke to get 427? My numbers show a 4.125 bore x 4" stroke will do it, but that would be a sleeved or custom block?

 

[Cleveland Crush]

CHI 3v intake, carb pad shaved about 1/2" for hood clearance but not necessary if using a drop base air cleaner; Hooker Super Comp headers. Needed to "relieve" the "8 header tube slightly because it touched one of the bolts on the steering box cover, 20-20 hindsight I could have simply used a button head bolt in that particular position for the clearance. The CHI exhaust ports are only 1/4" higher then factory ports, they don't cause any trouble.

 

[Cleveland Crush]

Impressive! What intake are you running with the 3V heads? Are you able to run stock pattern headers? Any clearance issues with headers? I don't know anything about the 3V's but have read that the raised exhaust ports can cause fitment issues.

Edit: Oh, and what is bore x stroke to get 427? My numbers show a 4.125 bore x 4" stroke will do it, but that would be a sleeved or custom block?

Correct, 4.125 x 4.00" Titus Cleveland block

 

[basstrix]

Iron 4V CC heads 69cc, SCR 9.7, DCR 7.7, Mahle pistons 20cc dish, 91 octane, no detonation. I should have used more compression and more cam lift. It still made 529 BHP and 496 BTQ. If I were to pick an aftermarket head today it would be the CNC ported TFS. The CHI and SCM heads are great but ,WAY over priced, especially in light of the current exchange rate. Again, just my opinion. If picking a piston today it would be Auto-Tec. Excellent quality and up-grades are reasonably priced. Chuck

The kit under consideration (TMeyer's 4" stroke kit) offers flat top, dome, or dish. The CP brand dish pistons he shows on his site (and I assume they are what he puts in his kit) are 20cc....so that puts me in a similar SC/DC range. If I were to use a pair of my D1AE heads at 67cc and a 14cc dish, I'd be about 10.3 SC and 10.8 with 62cc (presumably on a TFS head). I guess I need to talk to TMeyer about 14cc dish pistons.

 

[Tnfastbk]

AFD will make the combustion chamber to whatever cc you want them to be. When I did the math on mine the compression was to high for what I wanted. Two ways to attack that. One is to use a thicker head gasket set . Cometic and other I'm sure make them. But I chose to have AFD open them up a bit and have had no issues with them.

 

[turtle5353]

AFD will make the combustion chamber to whatever cc you want them to be. When I did the math on mine the compression was to high for what I wanted. Two ways to attack that. One is to use a thicker head gasket set . Cometic and other I'm sure make them. But I chose to have AFD open them up a bit and have had no issues with them.

I went with the slightly thicker custom head gasket from cosmetic to get my squish where we wanted it.

 

[bill1101]

Is 93 octane gas common outside of California? I can't find it here

 

[Sheriff41]

Is 93 octane gas common outside of California? I can't find it here

We have it in Texas.

 

[Cleveland Crush]

93 is at virtually every gas station in PA and OH

 

[basstrix]

Would you feel comfortable running iron heads at 8:1 dynamic CR? A static CR of 9.6 has been suggested but that leaves me much lower on CR when I switch to aluminum.

 

[c9zx]

I would not hesitate to run 8.0:1 DCR with iron heads and a SCR of 10.00-10.25:1. Chuck

 

[boilermaster]

I am running 10.4 and 8.2 with my 408 cleveland, no whimpy gears and make sure you know how to dial in an ignition curve.
I am doing this on 91 octane fuel, we have 93 octane with 6-8 % ethanol, my mustang does not like this and my shovelhead hates this fuel.
Boilermaster

 

[basstrix]

I am running 10.4 and 8.2 with my 408 cleveland, no whimpy gears and make sure you know how to dial in an ignition curve.
I am doing this on 91 octane fuel, we have 93 octane with 6-8 % ethanol, my mustang does not like this and my shovelhead hates this fuel.
Boilermaster

Just so I'm clear, that is using iron or aluminum?