What is the most comp I go with on pump gas 94oct?
09-28-2008, 10:15 PM
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What is the most comp I go with on pump gas 94oct? What is the most one could go with (compression ratio) on 94 octane pump gas?? This will be on a carberated 383 LS1.
09-29-2008, 06:30 PM
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Well I don't know how spot on the tune will be a first. It's carbed and I will be using a LC-1 AFR gauge and controlling the timing a MSD 6LS ignition system. And I don't really know **** about tuning something like this. But luckily my buddy is pretty smart with carburated stuff, so I think we will get the hang of it pretty quick.
With the figures I have plugged into a CR calculator, which I'm guessing on the deck height -10 out of the hole and gasket bore at 4.00" the bore is 3.905" and I know it is slightly bigger then the hole. We are going to measure tonight to be exact, I come up with around 12.5 to 1 CR.
With the figures I have plugged into a CR calculator, which I'm guessing on the deck height -10 out of the hole and gasket bore at 4.00" the bore is 3.905" and I know it is slightly bigger then the hole. We are going to measure tonight to be exact, I come up with around 12.5 to 1 CR.
09-29-2008, 10:04 PM
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Wow, I'm looking at 12.6 to 1 with a .050" head gasket or 12.95 to 1 with a .040". Looks like I will HAVE to run race gas. Or at least cocktail it with 94 oct with a very safe tune.
10-08-2008, 10:38 AM
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I have read about guys getting away with higher compression on pump by having big cams that allow for a Dcr that will cooperate with pump gas and a bit higher compression. For example, Patrick G's 347 build that used a big cam and telve to one compression.
10-09-2008, 08:01 AM
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Well, I went with a cometic .051" mls, 3.910" bore. The piston is .011" out of the hole, 58cc chambers and -2cc pistons. That still puts me at 12.5:1 CR. I'm good with that!
