Here's the email I got from my JDM vendor:

Brother,

Here are the things you want:

USDM AP-1
Head Gasket 12251-PCX-004
Piston 11.1 13010-PCX-A00

JDM AP-1
Head Gasket 12251-PCX-004 (same as USDM)
Piston 11.7 13010-PCX-000 ( different)

**all USDM pistons have an A at the last three digits and the A stands for America.

What do you guys think?

 

uhh ohh

 

Sounds like a lot of work for 6-7hp. Anyway, why stop at 11+? Doesn't Spoon have the whole ensemble? What octane do they require? They do have a larger RADIATOR available, right? water pump? oil pump? What HP gains do they claim? Isn't their philosophy based on streetable power?

But, it all the competition Honda has drummed-up, they've got no choice but to come up with an S2200? S2500? V5? I'm trading-in when that comes. As long as it's a ragtop.

 

Also to keep in mind. The pistons ont he S2K comes in two sizes to better fit the bore. I'm not sure is this is the letter Richard mentioned.

Took compression reading from two S2K the other day and it varies a lot, hence another reason for some dyno number varying from car to car.

According to the service manual the compression should be 228 PSI with a maximum variation of 28 PSI

My car: Mileage 15,000
Oil: Regular

Cyl #1: 230
Cyl #2: 230
Cyl #3: 220
Cyl #4: 217

Race Car: Mileage 17,000
Oil: Synthetic (Motul)

Cyl #1: 240
Cyl #2: 240
Cyl #3: 238
Cyl #4: 247

I took the readings on the race car after a prolonged idle. The other car were taking with three bars but the fans never turned on. Maybe the reading could go a little higher. Will keep on taking the readings on the race car after each race to see how the F20C stands to the abuses of racing.

 

What's the viscocity of the Motul you are using on the race engine?
Are you using Motul 300V ?

 

[QUOTE]Originally posted by mingster
[B]Here's the email I got from my JDM vendor:

Brother,

 

If I remember correctly 5W30

 

Still doing the mod though. Hoping for the best

 

As Pepe pointed out, hoping may not be needed.

Sounds like your having GREAT FUN, wish I had the time. Just monitor that knock sensor.

 

Make sure the comp check was done with the TB at WOT. As far as the letter after the piston number, this could be the grade of piston matched to the bore.
I dunno, still waiting on my FSM.

Once you pull the head off you will see a stamp showing which piston grade to get. It would be nice to run a cork-bond stone through the bores as well. Add new rings and 500K to let them seat. But we are talking a full rebuild here with the crank coming out. You cant knock off the conrod bearings and pull the piston through the top ;-)