Hey there guys and gals! I am new too the import world here and have a question.

Here first is what I have for motor....

1997 B18c JDM Type R
Max port and polish on the head
4-1 headers with catless exhaust
AEM Cold air
All else stock except 82mm pistons going in.

My question to you is quite simple. Unfortunatly we couldn't find any JDM style pistons so had to go with the USDM style which is going too loose me a bit of compression.

Now, im looking too boost that back up. Will going with a Cometic .030 head gasket and milling the head achive me what I want and getting that compression back?

Also, we have an OBD1 p28 ecu in car right now and I was thinking of replacing the OEM Type R cams with S2 Stage 2 cams. Was told this may not be wise bc we're putting in the thinner .030 head gasket and milling the head (potentially). Was also thinking of match porting the OEM Type R intake too the head.

Any advise from the pros?
Thanks tons

 

OH! And if course I forgot, was going too be getting a set of s2 cam gears for the tuning after the pistons are installed and the motor is rebuit. OEM or S2 Pro 2 cams pending lol

 

Bore over only as far as you need to to restore squareness to the bore. 81.5 is sufficient. If you mill the head use a gasket that will fill the created clearance unless you plan on degree'ing the motor to compensate for the difference in cylinder head/block height.

I would stay near 91 or 93 octane compression levels to keep it streetable on pump fuel, we all have our preferences, do as you wish.

In my experience cams have yielded excellent results, I would go this route myself. I like Honda gaskets, my opinion though.

Get a good tune, Hondata etc.

 

Run an 81.25 JDM piston and keep the compression.
Next word of advise...send me your tranny

 

Unfortunately we weren't able too find when we were looking replacement JDM pistons that allowed us too keep the existing rods so we had too move over too the USDM Type R pistons and theyre not returnable Hense the cutting of the head too try restore the compression back to JDM specs. There is a plan however too adjust the cans tming too compensate for this adjustment with head. My builder says I won't need adjustable cam gears but I don't see how cams can be adjusted w/o them :s

As for cams, I was thinking of going Skunk2 Pro's with a tune but so many threads are going back and forth between " change the stock itr valve spings and higher the compression " and " stock itr valve spring and retainers will be fine for stage 2 cams "....can anyone tell me if they have positive or negative experience using stock itr valvetrain with Pro stage 2's??

Thanks guys

 

93eg; if I send you my tranny then itd be a lil hard too get around :-P

 

op I'm kinda in the same boat... have to bore over want to keep the c/r up and want to keep everything on budget... aftermarket pistons might be the only option for us...

someone had mentioned to me RS Machine made a good piston for a good price, but I cant find any info on them or reviews...

 

Naw I'll send you my S4C w/ LSD

IMO the best RS machine piston for the GSR crank/rods are PR3's. They put your CR at 11:1 at a minimum. With a GSR head it jumps up .3 compression points and you can manipulate from there. Thinner HG, Flat faced valves and head milling when all used right will get you the static compression you want and still keep tolerances decent. IMO a GSR w/ 11-11.5:1CR skunk pro 1's, tuner 2's, jun 3's, BC3's or Rock m22x's are all killer cams.

 

RS Machines USDM pistons are actually the ones I ordered lol The machine shop recommended we used them and says he swares by them so RS Machine it is!

Whats the difference between skunk2's Pro and Tuner series? :s

 

do they not make a JDM OS piston??

curious as to why you went with USDM rather than sticking with the JDM??

 

JDM pistons are only available in .25 overbore. 81.5 and up all that's available is aftermarket USDM style pistons.

Looks like you have some research and homework to do.

 

Ive been doing tons of reading up on the differences between the two. It seems that Pro vs Tuner is Pro has a...how do I say gain over the entire prm range vs a more vtec gain with the tuner series.
And seems as though tuners are easier too tune

 

Only if you have a tuner who is clueless. Any GOOD tuner has dealt with tuning cams that have larger than stock primaries and will have no problem getting them dialed in a running smoothly.