.25 over CTR pistons in a stock GSR???? can it be done?...how?

 

yes. it can be done.
just remove the old pistons, install the new ones. just be sure to check
piston to cyl head clearance as well as piston to wall clearance

 

You have to get your block rehoned(or bored) for the pistons to fit.

 

But won't the compression be approx 12:1?? ...That's pretty high for a daily driven street car isn't it?

- also what work would have to be done to the GSR head? i.e combustion chamber, new head gasket, what type of cams would be best to use

 

Civic Type R cams are good, but I'd go with Skunk2 Stage I's. If you get them you'd need to upgrade the valvetrain(valve springs and retainers), only if you're going to raise the rev limiter, which you should since these cams make power up there.
You can get a thinner head gasket to raise compression a little.

 

i'm still sketching about the 12:1 cr though......should i be sketching about it?

 

i'm running the .25 over ctr's in my b18c1. read a page that i believe katman wrote that said that this setup only produces about 11.5:1 comp. anyways, there is no knocking or pinging. just make sure you use 93 or better octane and have a fpr. oh and you will have to get the block bored and rehoned. it wasnt that expensive any machine shop can do it.

 

you got a link?

 

I have a GSR with JE 12.5 compression pistons and a gsr head.with stock 240cc injectors and a stock FPR and a prelude fuel pump on 93 pump gas...no problems here...runs strong..but i do have a p28 with a mugen chip with a apexi SAFC..

 

Run it through the compression calculator here http://www.c-speedracing.com/howto/c.../compcalc.html CTR pistons will give you 12:1 compression. That is what I am running now with other mods and no detonation