~240's okay, 280 doesn't sound right though

 

Carbon deposits?

 

my DRY results were

#1...250psi
#2...255psi
#3...255psi
#4...260psi


Seems PRETTY HIGH compare to what other ppl's test.(low 200s)
My car has 19000mile, never adjusted valve yet.

 

something wrong with my car?? or maybe it is the gauge??

 

I think you're fine. Maybe Dave or Bill can comment on why some gauges read so high...

 

I took the car to the dealer a couple weeks ago and convinced the service manager to do a leak down test, which they apparently haven't done yet, but which I WILL make them do, since they did agree to do it.

I did discover a few things while I was there:

1. The S2000 puts out a fair amount of "blow-by." I put quote marks on the term, since I'm not sure it IS blow-by - it could be air from the crankcase ventilation system or the valves or something else. I checked a band new 2005 model and it was puffing about the same as my 2001, so I felt a lot better.

2. The hydrocarbon smell I detected apparently was due to an over-rich fuel mixture, which was somewhat evident from the black soot on the spark plug electrodes. Still, I was getting really good gas mileage and did not see any trace of black smoke, so I didn't suspect that. The dealer said the air filter sensor (can't remember the exact name) was bad, and put that on order. Now I'm feeling still better.

3. As for the test results, the way I learned to do compression tests was to turn it over until the readings maxed out. I did the tests on a warm engine. My gauge is a decent one and threads into the spark plug hole, but it is by no means top-of-the line pro gear. From other tests I have done on other vehicles, it has been reliable. For my results, all the readings were taken at 6 cranks. At 4 cranks, I was hitting the 210-220 range - an extra 2 cranks would max out the reading around 220-230 for most of the cylinders. For the wet test, I did the same thing - I think the readings will vary based on just how much oil you squirt into the cylinder. Again, prior training taught me to do just one decent squirt, which is what I used for the readings I posted.

4. I remember why I love this car so much having been separated from it for almost two weeks. Not since I sold my 1992 Corrado SLC VR6 has a car made me feel this good.


All-in-all, I feel that the leak-down test should give a good baseline. When I finally get the results, I'll post them here.

 

its not blow-by. the s2k uses forged pistons which expand at a different rate then the cast aluminum cylinder walls.

 

The cylinder walls are not cast aluminium. The only car I know of that used aluminium bores was a Cosworth Chevy Vega, Not very well either.

The S's bores are Honda's proprietary FRM (fiber reinforced metal) that are cast into the block.

 

yes the s2k block is FRM, but its aluminum + fibers that are mixed together and then cast into engine blocks.

 

FRM bores are very different from "cast aluminum cylinder walls".
The block is aluminuim, the bores are FRM.