Biccins

Hello all, I'm looking for advice on my 2007 S2000. It has 130k miles and I have run the following tests. What would you do?

Compression
Cyl 1: 178psi
Cyl 2: 120psi
Cyl 3: 180psi
Cyl 4: 180psi

Compression w/ teaspoon of oil
Cyl 1: 240psi
Cyl 2: 150psi
Cyl 3: 238psi
Cyl4: 240psi

Leakdown
Cyl 1: 4%
Cyl 2: 18%
Cyl 3: 8%
Cyl 4: 8%

So - the car seems to be running okay, but I worry for its longevity with Cyl 2 being at 120psi 18% leak. When I first got the car it had extremely tight tolerances on the intake and exhaust valves.

The car is not throwing any codes. I used a borescope and I see no visible scoring on the cylinder walls (I'll have to pull the head to really see the extent of wear). With Cyls 1,3,4 at ~240psi with a teaspoon of oil, I'll assume that's normal ring wear. Cyl 3 seems to have more than just piston wear -possibly burnt valves?

I have the tools, space, and time to pull the engine. Under the assumption I open it up and there is no cylinder wall scoring... would you change the piston rings and lap in new valves as needed? I am looking to stay NA and extend the life of this motor as long as possible. If there are proven aftermarket parts as I pull the motor I may use those, but I have not seen much in the way of reliable aftermarket parts for our S2000s. Thanks all and happy Friday!

noodels

May damage head & further $ needed if not done,get the valves sorted on number 2
also may damage Cyl 2 piston crown if it runs too weak,then that may result in bore damage also.
Leave the botton end alone,so whip the head off only.
130k its just run in
If I was to remove my head again in situ, I would remove engine ,then can inspect replace clutch ect

Biccins

That's my worry, it becoming further damaged if action is not taken now. I will probably replace some other components upon inspection as well as clean the carbon while disassembled.

Zer0ne

I had the same issue on the same cylinder on my 2006 although your compression #s are lower. Valves were torched. The DBW cars run lean and need to have the valves adjusted more frequently because they tighten up quick.

Biccins

What all did you end up replacing?

Zer0ne

Entire valvetrain with new OEM. Probably could've gotten away with just the few torched valves, but I did it for peace of mind and to keep everything even. My shortblock was fine.

Singh_snisen

Drop a used motor in it. rebuild the current one later or sell

Biccins

Any advice on where to purchase from? There's a good handful of honda parts stores, but I didn't know if there's a good to go to for an bulk parts