I did a compression test on ap1 the other just to make surre things are in order, I was shocked to find my numbers were pretty high and my spark plugs were covered in white "ash" like the car is running lean.

heres the results:

1. 270
2. 265
3. 260
4. 270

do those numbers seem a little high? I have a rebuilt head(ss valves, ti retainers, dual valve springs) and oem bottom end

I'm thinking the head was shaved a little much but would that cause the car to run leaner? Is it safe to WOT?

 

bump

any input would be appreciated

 

yea man, they seem super high... I got mine compression checked (also AP1) after a accidental over-rev, and mine were about 100 psi short of yours.... each...

 

it have tons of variable, but the thing about compression test is that you look for the difference between the cylinder, instead of peak number

number can change by crank number, brand of gear, condition of gear, temp, battery condition, etc

my old gauge reads consistently 10 psi lower than spec, i know this because i tested it

 

The consistency is what really matters here. You are in excellent shape. Congrats.

 

engine warmed up? throttle chocked open? how many cranks? known gauge tested ok?

 

engine warmed. throttle wide open. 8-9 cranks or when the gauged just about came to a stop. the gauge showed perfect for a dsm the numbers were right on the money and I used this gauge before I redid the head but that was 2 years ago and I had 240 across the board not sure if age would screw the gauge up.

 

For a number of reasons (such as oil viscosity and the seal created), different gauges read different numbers. Focus more on the fact that the numbers are uniform across the board...a better indicator of a healthy motor.

 

well that makes me feel better but the spark plugs looked kinda weird to me

heres a example of how the spark plugs looked just a lot more whiter:



doesnt that indicate a lean condition? I'm not 100% sure what a normal spark plug looks on a s2000 though. Keep in mind that I've put about 40k on my car since I bought it and I've never changed them..probably a good time to do it

 

hmm they dont look too bad. greyish/whitish i think is fine.the electrode and the tips look fine to me...but whats going on with the where the washer is?