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piston comp
Posted: Sun Nov 16, 2008 3:55 pm
by bones
Ok, what is the best distance down the bore for the piston with nos, have heard that you shouldnt have the compression to high. Is 10ish ok or could it be higher, does this make any sence
rich
Posted: Sun Nov 16, 2008 5:08 pm
by Boosted LS1
Down the bore will make for a crap engine with zero squish when driving normally. It'll waste fuel and make higher emmissions. Build an efficient engine and inject the notrous later in the cycle imo.
Posted: Sun Nov 16, 2008 6:29 pm
by bones
cheers Boosted, so what depth would be ok, nos goes through a progressive controller and max will be 175 shot,
rich
Posted: Sun Nov 16, 2008 7:50 pm
by Boosted LS1
In an ideal world you'd want the piston at tdc to be no further from the cylinder head then .040".
Posted: Mon Nov 17, 2008 2:51 am
by bones
thanks for that, so somewhere between 0.020 and 0.045 should be ok, then i just hope ive got a 81mm crank
rich
Posted: Mon Nov 17, 2008 10:04 pm
by mgbv8
Rich
10:1 will be ok for nitrous. Mine is a 9.75:1 with the block decked and the heads skimmed using comp gaskets, so I'm pretty close to 10:1 anyway.
You need to make sure you knock enough timing out of it though when using gas or you could have a quick end to a good engine with bent rods or melted pistons.
Rule of thumb is 2 degree's of retard per 50shot of gas as a starting point.
Posted: Wed Nov 19, 2008 1:13 pm
by bones
not timing again, when i get to use it i will forget, or the controller should do that its a got a retard switch on it,
rich