Compression Ratio with pump gas??
#4
Junior Member
JOURNEYMAN
Join Date: Jan 2005
Posts: 27
compression ratio-pump gas
I have a 355 sbc with 10.5 flat tops. It previously detonated when I ran some old steel 64cc turbo Chevy heads, #340292. We replaced them with a set of 68cc AFR alum heads with 180 runners and the detonation went away. I don't know if it was more from the larger chambers or the alum head material, but I suspect it was more from the aluminum since it dissipates heat better. It's may be easier and cheaper to swap heads than pistons. JMO Mep
#5
Senior Member
RACING JUNKIE
Join Date: Sep 2007
Posts: 4,137
let me rephrase...mine was 11 to 1 on paper, I never measured anything and did the math. It was a flat top piston 406 with 5.7 rods and it had a small hyd cam .507 lift dur @ .050 was about 244 I think. It had a set of the original sportsman cast iron heads with 64 cc chambers( advertised I didn't measure them)