I've been plotting going ls/vtec on my ls for quite a while now. The main reason i want to do it is for the better breathing head. I don't plan to rev past 7000rpms, and i have a pretty reliable setup planned. I recently started reading about the rare JDM p8r b20 head that has 33mm valves and bigger ports, along with a 84mm bore. My first question is, will this bolt right up to a b18b? And my second question is, would the breathing of the p8r be comparable to that of say, a b18c1.
Would getting this head, with maybe some crower 403s, and some p30 pistons, make decent power? Anything near say, b16 head with stock cams, and p30 pistons (ls/vtec)?

Thanks for your help.

 

84mm combustion chambers would hurt your compression, no?

the valves are vtec size, so I guess it would be a decent upgrade, however find out about the effects on yuor c/r first...
-Mike

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AngelTeg &raquo;</TD></TR><TR><TD CLASS="quote">84mm combustion chambers would hurt your compression, no?

the valves are vtec size, so I guess it would be a decent upgrade, however find out about the effects on yuor c/r first...
-Mike</TD></TR></TABLE>

The P8R head is more comparable to the B16 head as far as flowing goes.

I do feel that the 84mm chambers will affect compression, but I believe there are other factors to worry about as well. I cant remember right now though. So IMO I would get a B20 Block or get some real good head work done to the PR4 or P75 head.

 

if you could remember that'd be great

 

with that head+some good cams and you would deffinatly want more compression you can make some good power........and it would probabbly be over 7000rpm so be prepared to upgrade your valve springs/retainers.

 

i still don't plan on reving past 7000, i was planning on using 403s if i got a p8r head.

 

friday night bump

 

ttt

 

it will not work with a b18 block, you need a b20 block

breathing should be comparable, close anyway

I've got a p8r sitting in my basement waiting for some 403's or 404s to go on in the summer

 

thank you BigC-ivic.

 

I just re-found this thread... my 403's are on their way