I have been adjusting my own valve for about 10 years, and I am embarrassed to say that I have been adjusting them WRONG on my S2000. The first car that I adjusted my own valve on was a NON-VTEC Acura Integra. The Helm's manual clearly shows that the valve clearance is measured between the cam lobe and the rocker arm. However, the Helm's manual for the S2000 clearly shows that the valve clearance is measured between the valve spring retainer and the adjuster screw. I did not notice this difference until today. Unfortunately, I did perform a valve adjustment about 6K miles ago, and I found that the factory valve clearances were "WAY OUT OF SPEC!". I was WAY WRONG, since I was measuring the clearances between the WRONG PARTS.

I consider this to be one of those "Good News and Bad News" situations, since a recent dyno plot (after the bad valve adjustment) shows that I had a particularly weak low end, while still having a decent high end. The valve clearance problem explains this, since the percentage of valve lift reduction is greatest when I am in the low RPM range. It also explains why my valve train was so noisy after the adjustment.

Basically, the difference between measuring the clearance at the cam lobe versus the adjuster screw looks like it is about .003". So basically, when I THOUGHT I was setting the clearance at .008" (intake), I was really setting it to .011". With the intake valve clearance set correctly at .008", the clearance between the cam lobe and roller rocker is now .005".

Am I the only dumb ass here, or have any of you also made this mistake?

No, you shouldn't feel like a dumb ass at all;) . The first car I ever adjusted valves on was a 2001 Integra Type R, and on that car, you measure between the cam lobe and rocker arm also (I think it's this way with all B series engines).

Then I went to adjust valves on the beater, a 92 CX hatchback. If you try the previous method of adjusting valves, you can't even get your feeler gauge in there! So I looked at the Helms manual a little more closely, and sure enough, you have the measure between the retainer and rocker arm. I don't know what differences are though, between valvetrain designs that would warrant two different methods of valve adjustment.:confused:

Gernby - It's good of you to post this so others may avoid the error you made. I consider myself lucky that my prior valve adjusting experiences were on valve trains set up like the F20C. BTW, I don't think it's related to whether the engine is VTEC or not as my old non-VTEC Civic Si adjusted between the valve retainer and adjuster just like in the S2000. It's clear how easy it would be to do what you did based on prior experience with an engine that has a different adjustment protocol.

Thanks for your moral support. I really do feel a bit of "gut rott" about it, though, since I know that too much valve clearance can cause valve train damage.

I forgot to mention that I had also adjusted a friend of mine's '02 S2000 valves. He and I have practically the same setup, and whenever either of us make a change, we do rolling start drag races to see the difference. To date, his has always seemed to pull on mine AT LEAST half the time. However, after I readjusted my valves (his are still done the wrong way), we had completely different results. We did several rolling start runs from about 3K to 9K in 3rd gear. For the 1st time, I managed to pull on him EVERY time. Every run, I led him by at least a car length by the time we reached 6K RPMs, and at least 2 car lengths by the time we reached 9K. I am REALLY glad about this, even though I have been missing so much for so long.

My friend thinks that I am going to readjust his valve, but I'm planning on playing him along until after I win the season autocross championships ... :LOL:

You may think you are playing me fat boy but the Prelude sans sunroof and roll cage will rip thy arse:D

Thanks for the heads up on this. I have been measuring it correctly.

I have about 36K on the car and have adjusted the valves maybe 4 times or so. Each time it seems I find less clearances out of spec., or at the measurement I would like.

With JR filter, Mugen ecu, cat bypass, Hondata gasket, Mugen header, Spoon exhaust, I dynoed at 229hp at Ultimate Lurkers today. Each time the engine got stronger with 4 runs, whereas stock ecu ones would decrease power after the second/third run due to heat issues and ecu compensation.

I think careful valve adjustment is important for optimum engine performance.

[QUOTE]Originally posted by Prolene
[B]Thanks for the heads up on this.

Before many of the mods, I got 202 on the underground roller type of dyno and 195 or so on the above ground dyno (Mustang?). This is with a 9/99 (model year 2000) S2000. UL has shown consistently that the later model years yield better dyno results, due to factory ecu tuning, I think. Mine and UL's run consistently VERY rich stock, thus with less power stock.

I am getting better at valve adjustments, and of course with less valve clearances being out of the lower of the spec range (where I want them), the faster it goes. Last time maybe 45 min, checking them all and adjusting 3-4 valves.

Yep, I'm pretty sure now, 2002's make more power.

I've dyno'd 3 stock 2002's on my dynapack. They have made 220, 219 and 217.5 hp to the wheels for an average of almost 219 to the wheels. Of the 3 stock 2000-2001 models I've dyno'd, they made 211, 212, and 213 whp for an average of 212. When comparing the curves, the 2002's are definitely more powerful, especially above VTEC where the whole curve is elevated.

I don't know if its ECU (the fuel curves don't look much different) or something else (cams? time to check part numbers), but I'm pretty certain that something is different about the 2002s.

UL