LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Compression for pump gas

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Old 01-18-2011, 10:55 PM
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Default Compression for pump gas

Ive searched and all I get is what gas to use for boost cars and **** in Cali came up so I've DONE a search and nothing.

As in my sig I'm looking to get a game plan on the 355 and was wondering what kind of compression i could run with pump gas

the game plan thats not set in stone is

355 Forged Pistons
stock crank re machined up since they seem to be quite durable
LE2 heads with a nice sized cam
and wanting to shoot it with a 200 shot
and of course all the extra bs injectors tb etc....

But big deal is what I can get compression wise??
Old 01-18-2011, 11:00 PM
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12.5:1 static is not uncommon for LT1s but sometimes frowned upon who aren't familiar with the LT1s ability to handle high compression. Reverse flow cooling really allows for a lot of advance under higher cylinder pressures.

For a street car I'd target 11.5-12.0:1.
Old 01-18-2011, 11:03 PM
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Alright thanks Joe

Seeing as I want to do the Street Stock class I'm going to have this motor on a motor stand for a while once I get it then probably get the itch to want to put it in and buy a cheap LT1 F-Body and put it in that for fun but we will see how things turn out September is a LONG way away.

But anything to make the motor more Nitrous friendly I haven't dealt with N20 at all and there has to be things to help the motor out when its on the laughing gas.
Old 01-18-2011, 11:12 PM
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like joe said. 11.5-12:1 is good. Race gas is a must if you want to spray it though.
Old 01-18-2011, 11:19 PM
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Originally Posted by Wicked94Z
like joe said. 11.5-12:1 is good. Race gas is a must if you want to spray it though.
But in the building process what is there something you do different other then go with forged internals to make it more Nitrous friendly
Old 01-19-2011, 03:31 AM
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for a mild hit like that, just open up the end gap a few thou, depends on bore size and ring manufacturer though. Otherwise nope...
Old 01-19-2011, 07:20 AM
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just like these two guys above said...........id stay under 12:1 and on the shot race gas is a must........
Old 01-19-2011, 08:25 AM
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Thanks guys I'm sure my guy at the machine shop will know what to do with the short block just need to tell him what I'm looking for and he will hook me up with what I need.
Old 01-19-2011, 11:24 AM
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I'm running ~11.5:1 and I never get detonation, even in 100 degree summer weather.




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