I want to upgrade the valvetrain on my AP1 using the Kings Performance street spec valvetrain kit. I'm new to the S2000 world and learned of the AP1 retainer issue, so I thought ehh why not just replace it all. I'm the 3rd owner of the car, which was previously boosted by the 1st owner but removed before he sold it to the 2nd. I've talked to Kings and they said a port and polish wasn't needed on the F20C and a buddy of mine told me that upgrading the valves on the F20C wasn't necessary. I want to make power in the 500whp range. Is my buddy right about not needing to replace the valves?

 

Yes

 

If theres nothing wrong with your head, just an ap2 retainer upgrade would be fine. Otherwise, upgrading just springs and retainers would be okay too. Billman on this forum created a thread on aftermarket valvetrain parts and its reliabilty or lack there of...find it, its a good read.

 

Thanks guys. Much appreciated.

 

The head on this car is capable of supporting 500+whp easily. No porting, no valves, or springs are needed. Some think they're useless, but I'd toss on a block guard if you plan on running over 15 psi of boost. 16 psi is ~ 510whp on stock compression.

 

There is no "AP1 retainer issue."
Care to enlighten us?

 

Think twice before you jump. See Billman's thread referenced above. "Upgrade" might be a misnomer. "Downgrade" might be more accurate.

 

Or go with Honda performance F1 spec valve train kit (comes from factory)

Best "upgrade" to the valve train is proper retainer inspection, and valve adjustment.

Currently at 150,000 hard miles, 100% original AP1 engine including retainers, one valve has moved .001 in all that time. There are thousands of others all oem, with the same story.

Aftermarket parts are no match.

Perhaps some documentation of the lengths Honda went through to create this F1 spec engine may convince people. In the end, time will be the proof.

 

Hey billman, would you recommend all factory honda parts even on a 500-600whp turbo s2000?

 

My AP1 has 170K miles, and many track days.
With proper retainer checks, and valve adjustment. I have been able to keep the OEM head in tip top shape with no issues.

For the next service i will be performing, i will be putting in AP2 retainers, just to be proactive with engine ware.