Anyone know the actual compression ratio of......

[DamnDisLaOsBoY]

a poor man type r? gsr short block with USDM b16 head off a b16a2 and lsd gsr tranny? i was wondering if anyone knew what the ratio will end up to be since the b16 head would raise up the compression a bit?? everything motor wise completely stock.

[PRO®]

a poor man type r? gsr short block with b16 head and lsd gsr tranny? i was wondering if anyone knew what the ratio will end up to be since the b16 head would raise up the compression a bit??

"using a 100% stock (undecked, standard bore etc...) GSR block and a 100% stock (unmilled, standard valves, combustion chambers etc...)PR3 head:

USDM ITR(P73-A0) = 10.8:1 compression (no shocker there)
USDM B16A(PR3) = 11.03:1 compression

Now here's where it gets interesting...

JDM B16A(P30) = 11.24:1 compression (dome is 6.93cc)
JDM ITR(P73-00) = 11.32:1 compression (dome is 5.96cc)"

http://www.honda-tech.com/showthread.php?t=1783523

don't know if thats 100% correct, just my attempt at helping you, lol.
so according to that, if its a usdm b16a head, the ratio is 11.03:1
and if its a jdm b16a head, the ratio is 11.24:1.

[SixSquared]

^^Wouldn't surprise me. I think JDM engines do tend to be a bit higher compression. I know most of the rumored hp differences and whatnot go out the window when they get brought over here, cause I believe in Japanland they use higher octane fuel, and so once you put the lower octane US gas in, the hp gains become nullified.

None of those numbers look extravagantly high or low, so I would agree that they are either 100% accurate or pretty darn close.

[DamnDisLaOsBoY]

"using a 100% stock (undecked, standard bore etc...) GSR block and a 100% stock (unmilled, standard valves, combustion chambers etc...)PR3 head:

USDM ITR(P73-A0) = 10.8:1 compression (no shocker there)
USDM B16A(PR3) = 11.03:1 compression

Now here's where it gets interesting...

JDM B16A(P30) = 11.24:1 compression (dome is 6.93cc)
JDM ITR(P73-00) = 11.32:1 compression (dome is 5.96cc)"

http://www.honda-tech.com/showthread.php?t=1783523

don't know if thats 100% correct, just my attempt at helping you, lol.
so according to that, if its a usdm b16a head, the ratio is 11.03:1
and if its a jdm b16a head, the ratio is 11.24:1.

damn! it would jump to mid 11s? i wanted to do a factory rebuild with keeping the b16 head. and maybe boosting it sooner or later after. hmmm maybe it would be a good idea for a thicker head gasket? i kinda wanted to stay around the 10 ratio for a decent NA and better spool once i boost.

[SixSquared]

OMG I know I didn't hear you talk about boost and a type R. Seriously?

If you want a N/A all motor build, go Type R or poor man's R.

If you want boost, go LS/V.

High comp + boost = Boom.
Low comp + boost = Zoom.

[DamnDisLaOsBoY]

OMG I know I didn't hear you talk about boost and a type R. Seriously?

If you want a N/A all motor build, go Type R or poor man's R.

If you want boost, go LS/V.

High comp + boost = Boom.
Low comp + boost = Zoom.

no i know about boosting itrs... but i just didnt think that a stock gsr block with just a b16 head would sky rocket the compression like that. just have a b16 now with gsr tranny. just wanted to put a 1.8 bottom end on it. but i think a thicker head gasket would lower it to the 10s? what do u guys think?

[RedEj8]

Using this. http://www.zealautowerks.com/bseries.html

With stock gsr pistons I got only 9.8:1. I duno if you're using Type R pistons though or if the head has been milled...Or if this site is correct.

[DamnDisLaOsBoY]

Using this. http://www.zealautowerks.com/bseries.html

With stock gsr pistons I got only 9.8:1. I duno if you're using Type R pistons though or if the head has been milled...Or if this site is correct.

reps!! nice find!! yeh i did it and got the same thing. 9.8 would be perfect for boost!

[AnthonyF]

^^Wouldn't surprise me. I think JDM engines do tend to be a bit higher compression. I know most of the rumored hp differences and whatnot go out the window when they get brought over here, cause I believe in Japanland they use higher octane fuel, and so once you put the lower octane US gas in, the hp gains become nullified.

None of those numbers look extravagantly high or low, so I would agree that they are either 100% accurate or pretty darn close.

i would have to agree with the higher compression with JDM equipment. We purchase items from NAD Auto and they get items straight from japan and they always feel much stronger than USDM stuff.

-Ant.