Damian

iTrader: (89)

I know on the older SBC's they should read around 125 psi, and the lowest cylinder should be no lower than 70% of the highest. Does this stand true for the LS1's?? If not, what are some roughly good #'s for comparison? TIA

Josh

cablebandit

iTrader: (37)

my car, stock, ran 180-185psi. Rons turd, who knows <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Ron@Vengeance

iTrader: (51)

Lmfao @ Jerry, Thanx ******** <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Actually,I got my passenger side head off today. Both the middle cylinders were leaking through the broken O rings in the head gasket. I have the drivrs side one ready to come off, just gotta get that damn power steering pump off. I cant seem to find the right size wrench to fit the top bolt. O well, time to go to work.

GeorgeC

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Damian:
<strong>I know on the older SBC's they should read around 125 psi, and the lowest cylinder should be no lower than 70% of the highest. Does this stand true for the LS1's?? If not, what are some roughly good #'s for comparison? TIA

Josh</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">It's hard to say what number to look for, since so many factors can come into play. The main thing you're looking to see is that all the cylinders are pretty close to each other (I'd want a little more than the 70% you quoted). Your camshaft, how it's installed (advanced/retarded), the temperature of the motor, etc, will all change the numbers you'll see on a cranking compression test.

Scalpel

iTrader: (4)

You should want them w/in 15% of each other, in my opinion and greater than 100 PSI in each cylinder.

cablebandit

iTrader: (37)

Ron that kinda hidden bolt is a 15mm....OR you could just leave it on the head like I did and take it off when it's on the ground. Be careful with the ps pulley. its "plastic" and will crack easily.

Max@Cartek

I would probably try to get a leak down test done instead. Much more accurate and eliminates a lot of the factors that are not accounted for with a compression test.

Max