Here sthe deal, i am goin to buy a full gsr with B16 pistons already in it...will it raise the compression or lower it if i put a b16 head on it? i have heard several diffrent things

 

you'll want to treat the motor as an ITR if you put the B16 head on it. I've heard that the pistons will be at a lower conmpression, because they are lower dome and geared for B16. ITR piston should have a larger dome and thusly raise the compression. I'm planning on doing the same thing in the future, so I've been doing some research. As long as you're going to get new pistons you might as well bore it to 84 and make it an all motor monster (if you have the cash).

 

Yea thats the deal, i will just keep it like it is and put in my CTR cams.

 

Any OEM B16 piston will have higher compression in a B18 block than any OEM B18 piston. The combustion chamber on the B18C1 (GSR) head is smaller (41.6) than the combustion chamber on the B16/ITR (42.7cc), so the B16/ITR head will lower the compression.

A B18C block with PR3 pistons with the B18C1 (GSR) head with stock headgasket (3 layer), and nothing machined off the head or block will give 11.37:1 compression.

If you use the B16/ITR head, the compression will drop to 11.12:1.

For all your compression ratio calculations, go here and try a number of different configurations:

http://www.c-speedracing.com/howto/c.../compcalc.html

 

no need for me to comment!
that's a good site to go to for info and even parts.

 

Aight heres the deal, i am gettin a GSR block, either CTR or ITR pistons? and my B16 head and ctr cams and maybe a ITR intake manifold or oversized valves? What do you guys recomend..and what do you think compresion will be?

I definatly will have a GSR block with a B16 head

 

Did you try the link I gave in my post above? All your questions will be answered if you go there.

 

you don't need oversized valves.... the ITR plenum would be a better choice to spend the $$ on. The above site mentioned should answer most of your compression ??

 

That site with the compression calculator said i would be running 11.65:1 compression, Sounds good to me. I will be running a mugen chipped ECU and probobly get a fuel pressure regulator. Will that give me enough gas to run 11.65:1?

 

with a chipped ECU be careful of the ignition timing map. you don't want to advance the ignition too much with a 11.65:1 C/R and on pump gas. though they're more $$ the Hondata systems offer custom tuning for your setup to make max power and avoid detonation. or leave the ECU the way it is for now and adjust the ignition timing through the dist. until you can get the proper tuning tools.

 

Right now my friend is running a stock B18C bottom end with a first gen B16 head and cams in his CRX. The **** is weak. I chipped the ECU with a Spoon program which is 4500/8500. The god damn **** bogs the motor with stock B16 cams. With that setup he ran 13.20@103. **** that head tho. P72 is the ****, and that manifold. PR3 may flow better but it doesn't really matter after it's ported. And the manifold will flow just as good once we take out the secondary butterflies and extrude hone it. plus you get that 0.2:1 bump in compression over the B16. The new motor is GSR with Golden Eagle sleeves bumped up to 85mm bore, 13.0:1 JE pistons, shot peened ITR rods, Portflow GSR head with port matched extrude honed manifold, Toda C's, RC 370cc injectors.

 

wow.... you must work for Honda then!!! I mean you're telling me that this GSR setup is better than any Type R from the factory?? God why couldn't Honda have thought of that sooner... Sorry bud but you're grossly mistaken. It may be the case for whatever you have done to that motor, but in the rest of the world PR3 heads are where it's at. The GSR plenum is too long to provide the proper air flow for NA, and might just be what your problem is... Think about it and I'm sure you'll see that you were incorrect.

 

Okay so you're tellin me that since we got a B16 head on a GSR block that we gotta ITR motor. Well if you consider a motor with 9.8:1 compression and the shittiest cam profile and manifold from the first gen B16 then you are right. Put P73AO pistons into a GSR along with ITR/CTR cams.... Which one do you think is gonna put down more power?? Also advanracing62 off the topic I see you know about JUN stuff... have they re-engineered those stage 3 camshafts?? My friend had them in his CRVTEC and their top end power was bad *** but the intake cam shattered and the motor went bye bye... A few other people I know have had the same problem but i was just curious if the problem has been fixed. Latez


[Modified by JDMspecEG6, 10:26 AM 11/6/2002]

 

Well that set your talkin about is just slappin a b16 head on a gsr bottom end right? Im talkin about changin pistons and puttin in CTR cams with a chipped ECU, and a ITR manifold, so i dont think my compression will be 9.8:1. We will c how it all works out

 

considering that a Type R is pretty much just a C1 with some diff pistons and such, and then a PR3 head with pnp, I would say that if built to spec it would be a "Type R" motor. Actually, it's called a poor man's ITR. You're correct about the crappy cam profile, and with the low compression it would be a better candidate for boosting at this point. If the motor was intended to be NA then I would think a better comp. ratio would have been used.

(OT) Yes JUN has corrected what was wrong... Mainly, it was people not using the whole head package. Portflow inners and what not are not as progressive as JUN springs, and are actually a tad stiffer than needed. All the extra pressure on the rockers and such caused accelerated wear on the cam, and extra pressure- Creating the shattering cam effect.... any cam will do it over time... It's just that there was a big JUN frenzy and so it seemed to be happening to most everyone.

 

Cool, thanks.. That's good to know cuz I loved those cams.