just want to no what the sandard compression ratio on my vu ss is standard heads and gaskets. The recomended ratio for the cam i want is 9.5-1. whats the best way to change the compression ratio. shave heads or new head gaskets
cam HYDRAULIC ROLLER: Street/strip, needs 9.5:1 CR , 2800+ stall, intake, gears, & headers, very rough idle. COMP CAM BIG MUTHA THUMPR THUMPER IN 235 EX 249 IN .573 EX .558 109°
vu should be the ls1 10.1:1 comp, i think the only way you could do it is to put dished pistons in, as shaving the heads will increase your compression ratio as your making the combustion chamber smaller in the way of the chamber/bowl on the heads becomes smaller increasing the comp. could put in a thicker head gasket, i know not ideal but would need to go to a .060-0.065" thick head gasket with standard head chambers, could still how ever do bigger valves and increased port flow without shaving the heads. could increase the bowl chamber size as well i think by machining/increasing the bowl diameter on the heads, which would help drop the compression a little, maybe enough with a thicker headgasket(don't quote me on that i could be wrong on that part).
who the fark told u to lower your compression? my ls1 has 9.5c/r and gets 15 pounds of boost shoved down its throat... up the compression if anything, lowering with make less power
iv seen the comp cam specs for this cam and it says exactly what phat vy posted, requires 9.5:1 comp, the book iv got says 10.1:1 comp as well for the ls1.
hmmm year i was going to shave my heads to raise the compression. i dont want to drop CR but that's what is recommended. I don't see what you gain by droping the CR, the smaller version of this cam said the recommended CR is 9-1. can anyone tell me what i would gain by lowering my CR.
Mate I think you will find that the manufacturers specs of 9.5cr is the minimum comp you would need to run this cam not what you have to have....the more comp the better, stick some e85 down its throat and go nuts on the comp ...do it
this should open up to it: 54-602-11 - Thumpr seen some good results from higher comp and E85 if you can find it, went in a cam and head package ls1 with higher comp and E85, absolute weapon, made an x amount extra rwkw, its won some dyno comps for n/a ls1, made 300+rwkw cam and head package on E85 and daily driven.
Mad year thats what i like to here migh give my tuner a call and see what he thinks. Has anyone used this cam, does anyone have some time or dyno results cheers
