Hemi pistons & increased CR

[Just Gary]

Does anyone sell ~9.0:1 cast or hypereutectic pistons for a .030" over 354 Hemi?

Stock CR is 8.0:1. I'd like to raise it to around 9.0:1, but without resorting to expensive forged pistons or boring the block out to 4.0" and using 392 pistons.

Application is a street car; stock heads, dual quads, cam: 220*@ .050 and backed by a T700R tranny in a 2500 lb car.

[Andy]

Can't help with a source for pistons. The 392 pistons will not work in a bored out 354. The pin heigth is different and the piston will be up or down(don't remember which) from where you want it.

[Machinos]

Actually, the stock compression ratio for a '56 354 hemi should be 9:1.

[laverda]

From my inquiries awhile back:
-Egge had stock pistons available
-PAW had higher CR available
-Hot Heads had the most selection ... even for my lowly 331 who needs some increased CR http://www.jalopyjournal.com/ubbthreads/images/graemlins/laugh.gif

Hope it helps.

Later,
papa al

[FeO2]

Gary,Can you mill the heads or use a thin head gasket,like I do on Chevy engines?I have an ultrasonic thickness guage if you want to measure how much you can mill. Charlie

[SKR8PN]

http://hothemiheads.com/research/hemi_guide.html
http://hothemiheads.com/research/hemiguide2.html

Try these guys.............

[Just Gary]

I stand corrected- Machinos is correct and I was wrong.

Stock CR is 9.0:1, confirmed by both my '64 Motor's Auto Repair Manual and Tex Smith/Ron Ceridono's Hemi book.

Still, I'd like to bump it up just a little... http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif Thanks for your inputs, guys.

[antichrysler]

Just to let you know that cost of a set of 10:1 pistons from Hot Hemi Heads is about $750. I would call them and get details on cams as well. They build a lot of engine and they have dyno numbers that will astound you. That 354 will get over 400 H.P. at about 5500 RPM. I can't remember the cam off hand but I do remember it's an ISKY 280 something.

[bulletproof1]

what is the hemi going in?

[Oilcan Harry]

Why not just leave it at 9:00-1? It will make plenty of power and tolerate todays gas a lot better. Gas quality gets worse all the time with additives and regulation, why not allow for it?

[Just Gary]

Oilcan Harry, you're correct r.e. poor gas, but the big advantage of hemispherical heads is compatibility with higher compression ratios and I'd like to take advantage of that.

Bulletproof 1, this is a long-term project; I only have time, space & $$ for one car at a time, so right now I'm only in the parts gathering stage. Eventually, it'll go into a 28-29 A Tudor, inspired by Gabby Bleeker's Austin sedan, but with dual quads instead of the blower and sufficiently roadworthy to take the family on cross-country Americruise & Power Tour trips..

[Shaggy]

Blower....

You know you want to