I got a Compression test today on my engine.
it was
1-175
2-177
3-177
4-175
is this normal like there is almost no difference between they cylinders i just do not know if this number is normal or not. i can not find it in my FSM. what should stock be??
also there are no leaks and everything is looks great.
Those numbers look almost perfect, and having consistent numbers between cylinders is great. At least I think so.
I’m no expert on the SR20 or KA24 engines but those numbers look pretty damn good to me!! Congrats! 8)
Those are really good i think i got 164-166 across mine last year. Ready for 6 PSI…
http://www.nissanperformancemag.com/may04/ask_sarah/
What are the specs are for the bottom end (crankshaft, connecting rods, etc.) of the SR20DET and KA24DE?
KA24DE: 2389cc DOHC 2.4L; high nickel sand cast iron block; 9.5:1 C/R; 89mm bore, 96mm stroke, 165mm rod length; forged steel crank and rods; main cap girdle; deep block skirts, fairly thin cylinder walls.
SR20DET: 1998cc DOHC 2.0L; sand cast aluminum block; 8.5:1 (Avenir and Bluebird) or 8.3:1 (GTiR) compression ratio (9.5:1 or 10:1 in the non turbo versions); 86mm bore, 86mm stroke, 136mm rod length; fully counterweighted forged steel crank; main cap girdle; deep block skirts; thick cylinder walls; beefy main caps.
Today’s atmospheric pressure was 101.20 kPa = 14.7 psi x 9.5 = 140 psi ??? Am I calculating this properly? Anyway, high & consistent = good! Go KA24DE!
sweet the guy that did them said they sounded good he just does not know what stock should be. i looked around and the average that is normal is around 165-170 so mine look mint. 6 psi here i come
Sounds like you’re using the weatherman’s “corrected” barometric pressure, which is just going to confuse the matter. Actual atmospheric pressure here in Edmonton is closer to 13.5 psia (we’re at ~2200 ft elevation)… and of course using the gauge scale, atmospheric pressure is always 0 psig, no matter where you are.
Your compression test number is a gauge pressure (eg. ~ 175 psig). And it is not calculated by atmospheric pressure x compression ratio. Your compression ratio is the volume ratio of your cylinder from bottom dead center to top dead center.