Hey honda tech world. I am building a B20\GSR that is going in my crx old engine was a B16
purpose of build: to have a competive Circuit race car
my question is what year engine B20 is good? and what is the engine code?
i dont know much about b20s only b18/b16 any info would be greatly appreciated!

So far this are the parts i have
GSR P72-2 head
sk2 pro 2 cams/Aem camgears
blox IM
Megan gsr headers
what i belive is a 98gsr hydro tranny
Rywire Mil-spec B-series engine harness just came in the mail today
Harness is all Ob1 at ecu and Alt/injectors/dist.
going to run Hondata S300
thats preety much it

 

96+

 

b20b or b20z.

 

Doesn't matter you'll need new pistons regardless.

 

You dont necessarily need new pistons... To take advantage of the VTEC head and the bigger displacement, higher compression ones are recommended.

Besides, I was illustrating to the OP which blocks to get. I dont want him to find a "smoking" deal on a B20A and think they're the same. Ya'dig?

 

Wrong - Anything bigger then b16 cams will hit the pistons.. unless he knotches the pistons to accept bigger cams he'll have a blown motor with anything bigger then that. Its known that people break / drop valves using itr cams in bone stock b20vtec swaps because the piston valve reliefs are entirely too small.

 

I see, on my first motor stock b20 block w/b16 head and gsr cams I had no issues. I however didnt beat on it a ton either.

 

gsr cams aren't really that much bigger then b16's. and it also helps to know which b20 bottem end..

 

Ummmmm yes he does if he's using pro2's.

 

i am running sk2 pro2 cams and will definetly need to upgrade all the valvetrain
buts thats for another day
is a b20b/b20z usdm or jdm?
also why is a b20a bad?
also with the cams i plan to use you guys mentioned pistons would JE HIGH C/R 12.8.1 84:5mm bore would work for me ? im think it will be good but want an opion

 

They're both JDM and USDM. It wont matter too much since your planning on using a different set of pistons.

B20A's are out of older Preludes like 88-91's. Theyre considered the bastard B, not much aftermarket support and they're a lot different in design then the B20B & B20Z.

I'll let them ALL MOTOR or bambam recommend the right compression piston to use. I will say a local (THE PATTON on here) used pro2's in his old crvtec w/RS machine 84mm "ITR" pistons, CCC ported head and made 226whp. I dont think the CR with those pistons is as high as what yours would be with the JE's but again we'll wait for them to chime in.

 

The best one to get if you plan on keeping the block stock is the JDM b20z, it is stamped b20b but is very distinctive cause it has a tall awkward IM.

But as previously said you cannot use aftermarket cams cause of p2v clearance

 

If you tear down the motor and knotch the piston valve reliefs your fine. Your compression then comes into play and from the way you come off, i'd grab some off the self 11.5-11.8CR pistons.

For people like you, i recommend RS, je or supertech pistons.. pricing is good and they have replica itr pistons.. alot of people go with RS..majority of the time.

With that said, to run a big cam, you need to have the support for it.. Induction is huge as well as exhaust.. you need a good header /exhaust.. flow matters when choosing a cam. Build your motor around your cam profile, not the other way around..

 

Do you plan on boring it? You mentioned 84.5 pistons, while 84 is stock. Additionally, there is an advantage to a larger bore other than increased displacement. You would be able to run a smaller volume domed piston while still achieving the same CR. There are distinct advantages to this.....many beyond the scope of this discussion. Cooler piston temps, lighter piston weight, and more resistance to detonation are a few.
As far as bottom end, if you plan on sleeving to 84.5 or larger, id recommend just starting with a b18a/b block as they can be had for cheaper and the oem cylinder wall design is better.

To the OP, will you be sleeving/rebuilding?

 

Also I do have experience with RS and JE. Both good pistons for an all motor setup. However they are of different materials. The JE's would require more clearance for expansion, however they are a good deal stronger than cast.

 

ok i see with the big cames and higher C/R I need my engine to breath better so i will be getting better headers thinking about bisimoto v2 and for the IM i am going to go with SK2 black series with a matching sk2 thorttle body. and for the pistons i will wait and see for now i do know its going to be JW OR SUPERTECH.
i found a shop in ontario ca called CT engines going to order the b20b block next friday will post picks next week of parts and build car THANKS FOR THE INFO !

 

i see ok im going with JE OR SUPERTECH pistons but thats later down the road.
i am not going to sleeve the block only hone it and put a golden or blox engine block guard
so i guess i am going to go with stock bore of 84mm pistons
i found a shop in ontario ca called CT engines and going to order a B20b next friday for 650 out the door :] thanks for info will post picks of the build car and parts next week keep posted.

 

$650 is a tiny bit pricey. Up here, I think b20s go for about $500. I guess that price is Ok as you're in a bigger market.

 

Yea that's pricey I got mine for 395$

 

i live in southern cali and and 395 for a b20b is unheard of at the shops around here maybe griegs list i could find it for a better price but i dont want to risk it