Valve Adjustment

[Tronn1]

I have 37k on my ap1 S and am thinking of getting a valve adjustment and new OEM plugs.
I would like recommendations as to the best valve adjustment specs, i.e., tightest to losest settings. I do not race the car and it has been running fine without any real issues.

Hello to all especially Svatne, Xviper and Road Rage (wherever he is).... I miss you guys...:rockon:

[repiv]

According to the AP1 service manual:

With cylinder head temp less than 100*F ....................

Intake: 0.21 - 0.25 mm
Exhaust: 0.25 - 0.29 mm

[CoralDoc]

I do a "precision" valve adjustment at the lower end of the specification on my car. The theory is that this will increase valve lift yielding more power. In practice, I can't tell any difference in power, but the idle usually smooths out a little.

Intake: 0.008" = 0.21mm
Exhaust: 0.010" = 0.25mm

Out of the 10 or so valve adjustments that I have performed on a variety of S2000s, almost all had some valves slightly out of specification (too loose), usually the intake valves. I think it's a good idea to do on your car once it's good and broken in (~15k miles). After that, subsequent checks (up to 65k miles) did not show much change.

The recommendation in the shop manual calls for an adjustment at 105k miles or whenever there is "excessive noise". If you're capable of doing this yourself, I'd do it. If you're paying the dealer (I've heard ~$180-$300 quoted), it may not be worth it.

[CoralDoc]

With regards to spark plugs, the OEM plugs are designed to last ~100k miles. I see no reason to replace them at this point unless you are having a problem related to ignition. I'd pull them, check them for deposits and damage, and reinstall them if they look good. Be extremely careful with the center electrode as it is very fragile.

[Tronn1]

Thanks for your responses... I do appreciate the info... nice being back... :tumble:

[svatne]

Tronn,
Great drive to Monterey this weekend. Fun getting lost looking for back roads on the way back, too.
Svatne

[dlq04]

CoralDoc,

Since you've done several now I'd be interested in your critique of these notes that I made several years back:

Valve adjustment:

On the S2000 the valve clearance is measured between the valve spring retainer and the adjuster screw, not between the cam lobe and the rocker arm. When you hear valve noise it may be time for a valve adjustment.

One owner reports adjusting the valves every 15000 and replacing the plugs every 25000 miles.

The first thing Scott at Kingmotorsports suggested to one owner was check the fuel pressure by installing a gauge. Honda has a gauge and adapter set up for about $50.00. It’s recommended you, buy a couple extra gaskets too. Reportedly says the same owner at wide open throttle you should set it to 60 psi not 55 (if you have an adjustable fuel pressure regulator) as the book says. The car runs very lean.

According to one owner a valve adj on an FC20 is a lot of fun. You need a 10 mm crowsfoot 1/4" drive for those few inaccessible lock nuts on the intake side. To get the valve cover off you remove the spark plug cover and remove the coils. It’s suggested you remove the cam angle sensors too as they will prohibit the removal of the valve cover. Then follow the instructions in the shop manual for adjusting. You can turn the crank shaft with a ratchet wrench to move the cams to the correct marks. Intakes .008-.010 exhausts .009-.011. He suggests you go over them twice. The firing order is 1-3-4-2 same as most 4 cylinder engines.

[repiv]

One owner reports adjusting the valves every 15000 and replacing the plugs every 25000 miles.

That seems too soon. :think:

[chuhsi]

after a properly done valve adjustment, does the engine sound like new? i still had that classic honda valve noise when i did my adjustment at 30k. power seems fine..just noisy