imported_GHT

i was talking to some mechanic yesturday and he was telling me that a b16 head on a gsr block will give you more hp and more tq to the wheels.... is this true or is this just a bad case of misconception. thanx for the help.

imported_t_dot_SiR

haha... the money you spend to buy a head and labour to swap it on properly... you're looking at some internal parts for your gsr!!! don't waste $$$ IMO

sohcnotec

A B16 head on GSR block will also lower your compression ratio a bit.

sohcnotec

BTW all these guys on the WD-40 B series shootout all use the P72 head. Must be a reason.


http://www.importtuner.com/bseriesshootout/

imported_t_dot_SiR

i think run b16 pistons on your gsr will yield higher compression... but you might as well grab ctr pistons if you want even more

Xscorpio

waste of money

chris_si98

1.6L pistons in a 1.8L block?

imported_t_dot_SiR

haha.. that was zeeman's advice on my built up.... i was wondering the same thing at first =)

zeeman

iTrader: (1)

Yup. B16/gsr/itr/ctr pistons are all 81mm bore, meaning that they're all interchangable. And b16 pistons in a gsr yeild a nice streetable CR and won't break the bank.
Now, the GSR head has different shaped intake ports and a smaller combustion chamber. Its debateable whether a b16 or gsr head flows better, but i would say a b16 does, why would honda use a b16 head as a platform for the ITR/CTR head? If the gsr was better than they would've ported the GSR head, added dual valve springs to the exhaust side, put the good ITR/CTR cams in and labelled it the ITR/CTR head. But they did that to the b16 head instead.
I wouldn't change the gsr head for a b16 head, if anything use a ITR head, but still for the money the gains are marginable at best. Use that money to build the gsr head. Or buy another gsr head and send it out for some headwork, get some internals for it, put it all together and swap it out for your stock one, then sell the stock one off to recover the some of the cost of the other head your bought and save yourself a lot of downtime. This is what i did.

imported_plzbeleiveit

i personally used a b16 head on my b20, i recently got it port and polished and added skunk 2 cams, springs and retainers. And noticed big hp gains. all of the top guys in the honda motor buidness tell me that b16 head is the way to go.

imported_GHT

thanx a lot guys for all the usefull information.

8.5K

almost every fast car uses the p72 head for a reason. do some research and you will find out why. and i don't want to here..."well, they used the pr3 casting on ITR's so it should be better" that's very misleading. as for the WD40 shootout, every builder was given a p72 longblock, so using a pr3 casting was not an option. lastly, an untouched 18c block with pct pistons will yield roughly 12.9/1 c.r. with p72 head. i'm talking unmilled head, untouched deck height. just a str8 piston swap. beware people

8.5K

didn't read your whole post, Z. anyway, Gord informed me of some different **** about p72 heads. there is a reason that it is preferred over the pr3 casting when it comes down to cfm and velocity. i figure H used the pr3 casting because they were massed produced vs. p72. pr3=civics/crx's/del sols, 2nd gen teg, 3 gen teg etc. p72=3 gen teg only. besides the fact that dual stage manifolds suffer in the top end.

LEITNER

huh?


misinformed.

i would use the gsr head. it flows virtually the same as the pr3. the reasons its my prefered head is not for any reason anybody has listed here. its about getting the prefered quench area without having to mill the crap out of the head and block. having a tight quench area and proper combustion characteristic are essential to eliminating the possibility of detonation. but everyone here like 11.5:1 compression so take it for what its worth.

zeeman

iTrader: (1)

This is exactly why i think honda would've used the p72 as the platform for the ITR/CTR. Seeing as the p72 has taller ports and a straighter shot at the valve and a smaller combustion chamber/better shaped combustion chamber/tighter quench area you would think it would make the better candidate for the R.
I just assumed there had to be some good reason why honda used the b16 head.
What are everyones reason for using a p72 head over a pr3? I need to know if i should dicth the worked pr3 head i have for a p72 on my current project.

8.5K

maybe you should moderate this forum, Z. its like you are the only other one that gets it. why am i NOT suprised you are the only one that posted this? some people just don't know

8.5K

o.k., i'll make it for u to understand......unmodded, single plate, fully functioning p72 IM's peak early and drop off rapidly up top, when compared to a single stage manifolds . aren't u using an S2 im on your 84 x 87? if i'm misinformed, slap a p72 on your build and make the same hp.

LEITNER

it was a pr3 head genius. you are misinformed.

zeeman

iTrader: (1)

aww....you're too kind....

But a non-paid member being a mod?!?!?!?
I know what i know from doing it, experience and research. I took lots of pictures of the two different head designs (pr3 and p72) when i was working on the last few i had in my basement. I was amazed to see how much different the intake ports were shaped on the p72 compared to the pr3, and how much better the p72 combustion chamber is designed and shaped.