jyeung528

it's been a while since i read this thread, but ap1 are good to go for longer intervals between valve adjustments, say 105K miles?

Chuck S

If you're asking the question you need to check your valve clearance. Let us know what it is!

When a buddy and I did our valves 2 years ago (I helped!) my '06 were where they should be. Many if not most of his '02 were tighter than than minimum spec and needed lots of adjustments.

-- Chuck

rpg51

I'm not letting mine go that long. I'm going to do open it up and check them next season. So it will be about 15K. If they are holding then I might go 30K next time. The job is easy and it gives me peace of mind, because I know what a disaster it can be if you burn valves. Not worth it.

Billman250

Currently setting all drive by wire cars (06-09) to .012 exhaust, .009 intake. This .001 goes a long way towards preventing burnt valves.

Contrary to belief, the S2000 valve train is not noisy. It takes about .014-.016 of clearance to be able to make out valve noise.

AP1s have proven to hold their adjustment at .010 exhaust, .008 intake. .011 & .009 is also perfectly fine.

Oregonjbird

So how about the 2004-2005?

simons

Im going to have my valves checked and adjusted. Car is Ap1 90k miles.

However, contrary to most info here my local s2000 specialist says the valves should be set to .25mm intake (.010) and .30mm exhaust (.012). He insists this is best for the engine.

Does the engine run differently on .010 and .012 than the tighter .008 and .010?

He says the valves will tighten up over time and will be too tight if he sets it to the minimum spec.

Im first asking advice here before he does the job.

Any comments please.

Car Analogy

If it were an ap2 dbw '06+, he'd be correct. They tend to run lean, so exhaust valves hotter, tighten up over time. Maybe he heard that somewhere, but didn't realize or remember its '06+ specific.

Ap1 tend to keep tbeir clearances over many miles. Oftenwhen people check them at your mileage or even more, they're all still in spec, no adjustment needed.

The reality will be what the clearances are when he does it. He should check if they're already in spec before adjusting. If they're even close to spec, his theory is blown. 90k miles and they haven't tightened up. Use stock specs.

If on the other hand they're somehow tight, then sure, he can go with the looser spec so less risk of burning a valve if they tighten up too much.

clubhopper

Running on the upper side of spec is acceptable and you will not perceive a noticible performance gain.
He is correct that the valves do tighten up over time. I personally run the optimal tightest spec as I'm able to check them myself more often if necessary. However its been documented that the AP1 valves when adjusted even on the tighter side of spec hold it for a very long time. Which is why I personally run them tight.

s2000Junky

I picked up my second s2k couple years ago (Ap1) and with 90k miles on the clock I recently checked the clearances and every single valve was at the min spec to my surprise. So buttoned it back up and will check them again in maybe another 30k.

chrisaltima

Bill set my 05 to .012 exhaust / .009 intake. I had a burnt valve issue prior to rebuilding head. The car has been running incredibly good at this setting. I would not hesitate to set an 04-05 to .012.