I was wondering if the B20B blocks that came with the P8R head had the PHK pistons. If it did, it would have a 9.2:1 CR and that would explain why it's listed on the jap site. I'm trying to figure out the CR on my P8R equipped B20B w/ P8R...I'm guessing it has PHK pistons. But, i want pics of it and also post what year your B20B engine was (u can look at the head year casting). Thanks...

 

mine were p3f. i sold them so i cant take any pics. it is a 98

 

or https://honda-tech.com/zerothread?id=990644

 

I'm not looking for just any pics of pistons. i want pics of the pistons from a p8r equipped b20b.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by erebunicrx &raquo;</TD></TR><TR><TD CLASS="quote">mine were p3f. i sold them so i cant take any pics. it is a 98</TD></TR></TABLE>
ok...so let me ask you this...did you ever measure the valve reliefs? I can't imagine them being the same as regular p3f pistons.

 

no i did not but. i think the valve seat on the intake of the p8r head is rasied up alittle.

 

ohhh ok....anything to verify this? Also, with the 49cc combustion chambers on the p8r head using the p3f pistons, it brings the CR down to 8.3:1. That just seems`crazy to me. There isn't any information about any 8.3 B20's....not even on the jap site. It's crazy. That would make this motor nice for boost...but, not for an all motor setup. It would throw off the ratio if you were to get upgraded pistons. For example, if you put 12:1 CR pistons in this motor, it would actually be around 11.5:1....

 

im not sure if the ls heads come with different size valve springs but there wer 2 different size springs in my p8r head. the in takes were smaller. when the machine shop went to put my crower springs in the seat pressure on the intake was 100lbs and the ex side was 60. also the intake was coilbound at .440 lift wich would make it impossible to run 404's

 

u sure? Darkane is running a P8R w/ great gains on the 404's....
here:
https://honda-tech.com/zerothread?id=940453
Besides...you can't run them without upgrading to the crower springs/retainers set.

 

what are your thoughts on the compression ratio? I'm curious...

 

humm. i did not know anyone else was running 404's in the p8r head. have you talked to him and find out if he did all the installation or did he bring it to a machine shop?

 

not sure. i saw that he gained 18HP on a mustang dyno without any tuning!....
it would be a good question to ask him tho.

 

up

 

id still like to know about that compression as well. i just picked up a p8r head for dirt cheap, and its in perfect condition. 49ccs seems like it might be too much

 

it is 49

 

so that means that P8R B20's have an 8.3:1 compression ratio! that's crazy....I was going to do an all motor setup, but im boostin instead 6 psi.....on the stock block.

 

did you have it checked, or just guessing? i checked the deck height to the quench area on the sides. a regular P75 is 3mm, the P8R is 1mm. dome height is the same.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eviloliv3 &raquo;</TD></TR><TR><TD CLASS="quote">did you have it checked, or just guessing? i checked the deck height to the quench area on the sides. a regular P75 is 3mm, the P8R is 1mm. dome height is the same.</TD></TR></TABLE>

if your asking me, i had it checked

 

god d@mmit...what compression does it have!!!!???

 

cant you just use a compression calc to find it out?

 

can someone tell me what car came with the p8r head? it's NOT a cr-v. those are either pr4 or p75.

 

its off a b20 from japan i think tose only came in crv's.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by erebunicrx &raquo;</TD></TR><TR><TD CLASS="quote">cant you just use a compression calc to find it out?</TD></TR></TABLE>

yeah i did...but it came out to be 8.3:1. I haven't been able to find any information about that....it's crazy....that seems like a perfect CR to boost on tho.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by erebunicrx &raquo;</TD></TR><TR><TD CLASS="quote"> its off a b20 from japan i think tose only came in crv's.</TD></TR></TABLE>
so any jdm b20 has this head? and basically it's an LS head with an 84.00mm combustion chamber?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mike K &raquo;</TD></TR><TR><TD CLASS="quote">
so any jdm b20 has this head? and basically it's an LS head with an 84.00mm combustion chamber?</TD></TR></TABLE>

no not all jdm b20's have them. it is like a 98 ls head (with the bigger intake ports) with a 84mm combustion chamber and 33mm intake valves. the same as a vtec head. also i compared it to my ls head and i thought the casting on the p8r was alot cleaner and smoother then the ls.

 

so where can i pick one up? anyone know of a source?