my numbers

[cham]

Ok guys I got everything I need and ready to boost the car. I filled out a information form for Rs-enthalpy. One question was engine compression. My bottom end is built with arias 8:8:1 or 8:8 something, built 8 years ago..bored over .20, KA sportsman rods, Clevite bearings The car has 45,000 miles on it Na. My numbers was 145 across all 4 cylinders. Is this right for these lower compression pistons? Everything including the head was stripped down and hot tanked. New valve seals and 3 angle valve job. All Arp hard wear including main studs. so they done a line bore. What do you guys think. I called HRT and I'm thinking about having the engine gone through before I boost it. The motor runs fine and strong. Just don't know about these numbers

[cham]

I just saw online that a wet test gives better results. I may try that

[gtrpryde]

I've read lower compresson pistons = low compression results.

My stock 150k mile KA was ~150 across the board and I've been boosting a modest 11 psi for about 8k miles.

Hope that helps.

[cham]

That helps. Just wondered because I search and found plenty others with higher numbers..Thanks

[adamky]

That's a little on the low side, but not bad. What cams are you running? S13, S14, aftermarket, etc.?

[cham]

S14 I suppose. The shop suppied the core 8 years ago. The car is an s14 model. Since all 4 cylinders are exactly the same, would would be the problem?

[adamky]

Cams and cam timing both affect your compression numbers quite a bit. If you're running stock S14 cams (232/232), then those compression numbers seem low to me.

[cham]

I can have the timing checked. When I got the timing done it was checked twice with the gun. I've advanced it a lot with the distributor until I heard no pinging. Been like that for a long time. Don't know if that affects it any. I still haven't done the wet test. But tell you what, the car runs, fires and idles like a champ

[adamky]

I was referring to cam timing, not ignition timing.

[cham]

Ok I'll get that checked. Thanks.

[cham]

Just figured out what you was saying. The shop lined up then chain marks and holes I'm sure. This guy does this for a living. But anyone can make mistake. I'll still get it checked

[cham]

Was I supposed to unplug my injectors? Would that cause lower numbers?

[cham]

160,160,155,155.....I'm worndering what's up with 3 and 4

[shift_down]

5 psi fluctuation is nothing to worry about. Numbers seem consistent.

[cham]

Ok cool. Ready to get my tune and fire it up. I'm getting a dual tune With e85 and 93 since my town has both. I got 1100cc fic injectors pushed by a stealth 340 pump. I'm hoping to get 350 or so on this set up. I'm gonna upgrade this winter and shoot for 450-500hp

[p00t]

So many things affect the compression numbers. Really just make sure they are consistent.

When I first got my car it had a huge 800 CCA battery in it... gave 195psi compression stock...