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Re: max compression on a 494 b uild
Posted: Mon Jul 22, 2019 6:49 am
by Piledriver
you are not allowing for the ramps... add 15 degrees to closing (50) per the instructions.
Put it together and run premium.
I suggest a scotchbrite finish on the chamber and piston crown, knocking off any sharp edges.
Polishing is counterprofuctive.
Re: max compression on a 494 b uild
Posted: Thu Jul 25, 2019 4:43 pm
by fusername
Not to sound stupid, but where are the instructions? Can't find em on the page.
At this point I'm with you pile. I have good gages, egt, cht, oil temp and finally, after years of waiting, an lm2 kit, just need to weld in a bung for it.
So hopefully if it will work, it will work, and if not I'll figure it out before doing damage.
Re: max compression on a 494 b uild
Posted: Thu Jul 25, 2019 11:30 pm
by Piledriver
Fourth line in UEMs "effective compression ratio calculator"...
"Intake Closing Point (Degrees)ABDC @ 0.050 lift +15 degrees"
It's an approximation, but it's only a ballpark figure anyway.
A tight deck is like free octane boost.
Also note it likely demands less timing, as the burn will speed up.