so Im about to go do my valve adjustment and have a quick question, should I be adjusting for the lower spec or higher spec. meaning intake shoot for .008 and exhaust .010



Intake clearance should be in the range of: .21-.25mm (0.008-0.010in)
Exhaust clearance should be 0.25-0.29mm (0.010-0.011in)


Thanks
Mike

 

I adjusted mine for the lower spec, the higher the spec and the noisier they'll be. Too low, and you risk burning a valve on the exhaust side. I haven't owned my S2000 for very long but I've read on multiple threads since I've been here that the clearances actually get smaller over time. That doesn't make too much sense to me but found it true when I did my first valve clearance. Following that logic, you'd want to check them more often than normal if you set them to the lower clearance.

 

let the car sit overnight to make sure the motor is COLD. if there is the least bit of heat in the engine when you do the adjustment you have an extremely high risk of blowing it up. A friend of mine had his S serviced at honda and the tech did not know the importance of having the motor cold when adjusting valves. he thought if the motor was luke warm everythign would be ok. Long story short, it blew up the next week.

 

Couple of thoughts.

For a quick valve adjust just turn the screw down to zero clearance (you should be able to feel it) and then back it out about 1/3 of a turn. the adjuster screws move .027" with each rotation, so 1/3 is .009, right in the middle of your spread. Takes about 15 mintues to do all the valves if you take your time. Less than ten if you hurry.

Clearances get tighter over time as the valve stretches both in the stem and in the head and from the valve "pounding down" the valve seat some.

And I wouldn't worry about burning a valve from getting too tight. Burned valves are REALLY tough to do in a four valve motor since they dump heat to the head so quickly. Also, with Honda's lense shaped combustion chamber, and center plug location, you really have to screw things up to get pre-ignition. I've run (by mistake) EGTs as high as 1600 degrees (normal is like 1280) and after three HARD runs (at the Salt ET's are like 96 seconds at WOT, most of it over 7700rpm) I finally warped a valve. But I didn't burn it. Same difference though, I guess, i.e., not much power and VERY hard to start. Oh well, OOPS!

Keep the shiny side up,

Jim

 

danvuquoc helped me through the process as I was doing it. seemed like I didnt need any adjustment at all. I have an 00 with about 40k on it. but this is good info to have up for anyone thats going to attempt a valve adjustment

thankss

 

Go for .008 on the intake. That is where mine are set.

 

Great info!

 

From experience, I like to pick a number in the middle depending on the application. With the S2000, I would feel comfortable with, Intake @ .23mm and exhaust @ .27mm.


Some times your clearences get tighter as time goes on due to wear in the engine. If your valve seats wear the valve will seat deeper into the head, resulting in a tighter clearence.