Avg. Cranking Compression On Lt1?
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Joined: Mar 2004
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From: Cleveland oh
Avg. Cranking Compression On Lt1?
My optispark swap turned into a cam swap- which turned into a spring swap- which turned into a head swap- which turned into an engine build. Soooo...I yanked the engine this weekend and I'm going through it. Will be porting the heads, swapping the cam, and doing a few other tricks while I'm at it. I'm upping static compression in addition to the cam swap (basically trying to maintain dynamic compression) and would like a few replies on what people are getting for cranking compression on stock LT1's. -Brian Nutter
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I'm a little confused as to what you want exactly. Do you readings from a compression test, or people to guess at their dynamic compression ration?
It sounds like you know what you're talking about so forgive me if this sounds too trivial. As it is your compression ratio will be determined by many things, the cam being the biggest factor in what your target static ratio should be. I would talk with your cam manufacturer and see what they recommend.
It sounds like you know what you're talking about so forgive me if this sounds too trivial. As it is your compression ratio will be determined by many things, the cam being the biggest factor in what your target static ratio should be. I would talk with your cam manufacturer and see what they recommend.
Melting Slicks
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From: Olive Branch (Memphis suburb) MS
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Originally Posted by briannutter
My optispark swap turned into a cam swap- which turned into a spring swap- which turned into a head swap- which turned into an engine build.
Thread Starter
Instructor
Joined: Mar 2004
Posts: 139
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From: Cleveland oh
stroked and poked.
With me driving 50miles a day back and forth to work, the last thing I need is a higher gas bill, so I'll stick with 350 cubes. As for dynamic compression Nathan, the longer the intake duration, the later the intake valve closes and the amount the piston travels up from bdc until the valve closes determines the net amount of air "trapped" in the compression stroke. This is why big cammed engines can get away with more compression. In this case, it appears I can go from 10.4 to 11.1:1 compression with the same cranking compression. This gets me the horsepower from the cam and recovers a bit of the low end torque lost from the bigger lobe. Soooo, back to the question of cranking compression with stock cam and longblock....any takers?
