DA-Flyby

I just bought a stock b20b block, i have a 95 GSR head. I know about that website that gives you an estimate on what compression ratio could be expected. But according to the site supposively Im gonna be at 9-2-4 ? Is that right? I just want to know the compression
http://www.c-speedracing.com/howto/c...c/compcalc.php

STOCK B20 PISTIONS
STOCK BLOCK(STOCK SHORT BLOCK)
95 GSR HEAD

DA-Flyby

NEED help here guys, Im about to send the head to get milled.

thabao

Dont mill anything. What B20 did buy? JDM B20b? USDM B20b4 or B20z4? Also, are you planning on boosting it?

If it's the B20b4, your compression is correct. That is a good compression for boost.

If your going all motor, i would get some PHK pistons from the B20z4. That'll pump your compression to 10.1:1

Or save up a $180 bucks and get the RS machine 84mm itr copies and that'll get you to 11.6:1

B20b4 are slow, slower than LS, even with a vtec head it'll be slow for an all motor.

DA-Flyby

its a JDM B20B

Im going ALL-MOTOR

RS MACHINE 84MM ITR copies, where can i get these??? $180? thats sounds great

I just can't spend 1000 on forged pistons and rods

thabao

Well since you have a jdm b20. 3 ways to see if it's the high compression one or not is:

1. look on the back, is there a knock sensor?
2. take off the head and see what pistons are in it. If they are PHK, its the high comp. If it's P3F, it's the low comp.
3. The year, what year is the motor.

DA-Flyby

they're P3Fwith no knock sensor. I want nothin less then 10-2-1. but that 11-6-1 with the itr copies sounds even better. What do you suggest?

thabao

Sorry for the confusion. The $180 for the RS is actually for the 81.5mm version. The 84mm ones run $310 shipped on ebay.

Now, if thats a lot for you, get the PHK. that'll get you to 10.1:1 still good for boost.

I would get the PHK, use a 2layer headgasket, and port and polish the head with a good intake manifold.

DA-Flyby

Im gonna go with the RS pistons(higher compression), should I run the 84mm or 81.5? im guessin the measurements are the length of pistons?

thabao

You should run 84mm, it's the width. The bore on a B20 is 84mm. You might wanna get a tune as well and run 93 pump gas only.

DA-Flyby

alright, so 84mm RS pistons im looking at 11-6-1 CR, is that on a 2-layer or 3 layer head gasket?

gshatch

you probally want to bore out the block to get rid of any damage

just do it right the first time

thabao

3layer

EG6Boy702

wont a bigger head gasket lower the compression?

skipper28-DC

Is this true for all B20vtec N/A? I want to build a setup just like the one discussed.