Street motor compression [Archive]

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ebeard94lt1

01-25-2010, 09:22 AM

So with how crappy gas is now i have heard that for a street motor 11:1 is pushing it. Anyone got any thoughts?

Low N Slow

01-25-2010, 12:16 PM

Static compression doesn't mean a lot, dynamic compression is what really matters. Depending on your cam you can go much higher than 11:1. I'm running 11.7:1 and have no problems running the shitty 92 octane we get out here.

1963SS

01-25-2010, 04:29 PM

^^^ Agreed. I'm running 12 to1 and have no knock counts to amount to anything.

Fastbird

01-25-2010, 08:11 PM

I was on 11.7:1 for a while with no issue.

96LT1355Z28

01-25-2010, 08:40 PM

12.1 here 91 octane without any problems.

popo8

01-25-2010, 09:00 PM

You gotta remember the LT1 is already a "high compression" motor with somehting like 10.5:1 stock. 11, is no where near pushing it...

ebeard94lt1

01-26-2010, 06:05 PM

Whats the differance in static and dynamic compression?

RamAir95TA

02-16-2010, 12:37 PM

The two compression terms almost define themselves. Static is just that - a static figure. It is the ratio of combustion chamber size from the bottom of the stroke and the top of the stroke. It is a static figure and never changes.

Because this article describes DCR very well, I'll just link you.

http://www.empirenet.com/pkelley2/DynamicCR.html

FWIW, my 383 is running 12.6:1 SCR.