A local guy is sellin a p8r head for pretty cheap, and I was wondering if I can use it on my LS block. Chances are that I cannot, just need some verifications.

 

i have never heard of a p8r head

 

P8R head is a JDM b20 Non-Vtec head. All the b20 in the US uses the p75, and the majority of the JDM ones also uses the p75, which makes the p8r slightly more rare. It is the only b20 head with a 84mm chamber and 33mm intake valves (like the vtec valves). It was thought to be from the Honda Orthia in 1997, some have also said that they have a 1999 head also, which should be in 2000 cars. The p8r code is cast into the head where the p75 should be. I was wondering if i can use it but the head is 84, and my block is 81, I thought it might have a chance for a fit. It is said to flow better than a pnp LS Head, and better than a stock gsr/b16 vtec head and it is stock from HONDA.

Some info on the p8r:

"This is a super rare head casting of a B20 head. Want to make good nonvtec power? Ports are different than regular LS heads, chambers are already opened up to 84mm, and intake valves are 33mm (vtec size). This head out of the box will flow as well as most ported LS heads, and you port this thing and get custom valves like another h-t member (fastone beast LS motor) you can easily be destroying vtec setups because of its 33mm intake valves seats."

Pics:

http://honda-tech.com/zerothread?id=796878

Basically, all the threads I've been seaching have mix information, I just need a yes or a no, and I want to know if It would be a pro or a con since I'd probably be losing compression due to the larger 84mm bore, but it would flow better due to the 33mm Intake.

 

I doubt that it would flow as well as a ported LS head. It will bolt up to your LS block, but unless you want a spare head to build up and then throw on your car when it's done, I wouldn't bother. Even porting a stock LS head and putting it on won't really do much for your car's performance by itself unless you have other things like cams/valvesprings&retainers/intakemani/tb/etc to complement the porting.

 

thanx

 

bcos the head from a 2000cc the combustion chamber is 2mm bigger than the sleeves on the b18. i have a worked p8r head on my b18... its got 11.5 compression now and i have a 4 into branch with 57mm exhaust and a chip to correct the fueling... and got abt 110kw true wheel power... oh and yes it flows better than the vtec head...

 

welcome to the boards, but please check the dates of the threads you post in. this thread is 4 years old.

anyway, do u have the CFM charts for your head to show that it actually does flow better than the vtec head? if so, please post them. and which vtec head are you comparing it to?

thanks

 

B16A2, but i mite be wrong on that... as far as i know the p8r head's valves are 33mm(correction), is that not the same as the vtec head? pm me if you can on this forum

 

I can't see having the combustion chambers bigger than the piston bore being good for combustion characteristics. I'd guess even with the bigger valves, this head would lose power to a P75 head on the same block with the same cams.

 

So far i can say i havn't lost power, bt i can't be certain until i get it mapped properly... y wud you loose power from bigger valves? the cams are from a 2litre so they peak lower than p75 from wot i have seen... my motor feels good bt we shall see if it lasts the dyno tuning