I have a b20z with. P75 head jus picked up a complete p8r head rebuilt n 3angle vavle job....I want to install with 403 cams....iam hearing it will lower my compression. Would I have to mill the head? Trying to go all motor 10:2:1 compression dd too

you can mill the head but you have to check piston/valve clearances so your valves dont hit...i would say just put pistons in it

Iam confused with the p8r head.. the valves are bigger tban my p75head..do I need to cut the pistons?or will the head bolt right up?

The head will bolt right up. I am running a stock block with 403's and a P8R head shaved 0.030" (almost all the way to the quench pads) with a 1-layer head gasket and still enough play with the V-V clearance and P-V clearance to do what ever I please with the cam gears despite the fact that the intake valve notches in the OEM piston aren't ideal.

What's ur compression? What head gasket are u using? What injectors?

you can use stock 240cc injectors. I've seen them good on 220whp just depends on tune

My static compression was around 10:1 I believe, but I will dig up my head info which I have written somewhere with the chamber size and let you know for sure.



I hope you are talking about HP at he flywheel and not at the wheels, because you can't rate injectors at a maximum WHP since drivetrain loss is never consistent, but at a minimum of 10%, that yields 242 hp, which at 60 psi fuel rail pressure would require 338cc injectors (rated at 43.7 psi) and 80% DC. If you were to use the stock injectors for that setup, you would need about 86 psi fuel pressure at the fuel rail. Good luck!

So unless you want to kill your injectors very quickly, you will never make 220 whp on 240cc injectors. I dyno tune cars for a living and with a compressed SiR fuel pressure regulator, the 240cc injectors hit 90% dutycycle on an LSVTEC making 165 whp, which is the same output as a stock Integra Type-R motor. (The ITR also runs at 90% duty-cycle, btw, and 80% is the recommended maximum for saturated injectors)

The injectors I am using are 310cc from an F20B.

oops yeah i mean at the flywheel lol

So I can use stock rails n injectors?

Yessir, you can. How much power do you hope to make?

170whp

or at least close too it...

You *might* be able to end up near there depending on the rest of your setup...

Just beware not to rev above 7500-ish if the rod bolts are stock.

Also know that above 7000 RPM I experienced valve float with the 403's and Crower's valve springs. Currently I am revving only to 7000 since my block is also stock, and I have Crower's stiffer springs that fit the B18/B20 heads. (68182 instead of 68181) I was told to shim the springs I had by Crower, but I plan to rev higher with more aggressive cams in the future.

Now it is possible that the springs I bought were tired since they were second hand, but upon measurement, they were still within Crower's usable specs.

^ yes - ARP rod bolts are very necessary if revving above stock 7 K or even with turbo to be safe.

I'm.not revving past stock redline 7200. I should b fine with stock rods n everything..

then you'll be good yes

OK, had head milled 25, just to be on the safe side, after taking it to the machine shop it was safe to say that it was milled because it was a rebuilt head, so 25 got me almost to the pads!!! whoa!!!

now where in the world did you find a single -layer head gasket? been looking everywhre?