Compression Ratio with pump gas??

Old 04-26-2009, 08:07 PM
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whitey70ss
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Default Compression Ratio with pump gas??

What is the max comp. ratio if I still wanna run pump gas??
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Old 04-26-2009, 09:48 PM
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Tod74
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I have ran 11 to 1 with premium gas with no issues. Most will tell you that's too much and maybe it is...but I got away with it.
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Old 04-27-2009, 11:24 AM
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ARUSSELL
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I am the same as TOD running 11.0 to 1, but 10.5 is a safe number to shoot for.
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Old 04-27-2009, 11:49 AM
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mep
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Default 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
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Old 04-27-2009, 02:28 PM
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Tod74
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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)
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Old 04-27-2009, 03:46 PM
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whitey70ss
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is there any way to measure comp. ratio with the engine in the car???
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Old 04-27-2009, 04:27 PM
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Tod74
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Originally Posted by whitey70ss
is there any way to measure comp. ratio with the engine in the car???
NO
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Old 04-27-2009, 07:00 PM
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suicidebomb
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Oh, Boy :!: :lol:
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Old 04-27-2009, 08:36 PM
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MEMRACING62
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are we going to use that magical compression guage again!! :lol: :lol:
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Old 04-27-2009, 09:28 PM
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Tod74
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Originally Posted by MEMRACING62
are we going to use that magical compression guage again!! :lol: :lol:
I almost went there but decided against it...lol
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