Frankacura

Get a B20 and have Crower II cams&Springs for your Stock P8R head. Get the B20 pistons's Valve notch larger for P8R larger valves and The Crower cams duration.
Have P30IM modified to fit the P8R head.
Have the cams DIAL IN and tune the motor.
You Gonna get Good Low Tq (2500rpm) and big Midrange (5500RPM) power till 7800rpm Cut Off
I dont recomand to rev stage II Over 8000Rpm
Peak Horspower might occur around 6800rpm to 7200rpm
Good luck

Black R

What rpm do you rev that EF race car to?

Frankacura

I shift it at 8200-8300 but i have to raise cut off to reach line in 4th gear at 8800rpm still in cut off just passing the line...
But i would like to pass the line around 8200
I will get 23' Slick against my 22

m4xwellmurd3r

Hey frank, I notice it looks like youve got some good knowledge on ported ls heads so I was wondering if I can get your opinion on the port work done on my pr4 head. Ignore the cut down valve guides, the head is getting rebuilt with full guides.

Cams are jge303 cams, .417 lift 274 duration, symetrical between int/ex

Frankacura

Hi M4X
My personal opinion about it at first is that is BAD to shave the valve guide like this.
Go on Youtube and watch the vid about Valve bouncing at 7000rpm
the valves is also forcing right and left. so longer is the guide. streight stay the valve.. a valve not streight aline on seats wont close properly in time. ( Good that you will repare it)

Also look like the one that did the work on the head try to polished his job on intake side, you dont want that, it have to stay at least cleaned on 80 grit. ( have it done as it will be apart)
air speed at the wall is 0. so you want a carpet of rolling air to let the Big air flow roll on it. It also will bring back in the port air flow the Gaz that is not well atomized and tempt to drop on port floor.. Can't explain all that here but its like that.
By the way some good work have been done, as cleaning around valves guide to let the air that hit the valves pass around and not going down in the port creating distorssion to the actual flow.
I dont Know how much he take care about grinding the same port size at every port. so you wont get variation of AFR between each other,
And at the End a Racing valve job will bring you lot more of flow if the porting is well done. As you can see my head Gain after valve job at .300 lift is not less than 22CFM Youll NEVER find those numbers without good head porting. On a stock head you usualy can make 9 - 14CFM Gains.
The Real race heads are usualy receving a Race valve job and bench flow after porting to really compare numbers.
And to me, more flow at .500lift to lost flow at .300 lift is not a effective porting job.
Some big compagnie are proud to tell you that they make a Pr3 B16a Head Flow at 310CFM@600 lift LOLOL But no cams make .600 lift in B serie. And these big head ports use to reduce air velocity so this is the reason you can't get good flow at .300 of valves lift cuz air is not running in the motor but sloly walking to it.
but an smaller intake Manif port can corect a bad ( Or To Big) ported head as you gonna get air velocity from intake but it can result in air friction to wall in bigger air demande from these smaller ports.
everything as to be TUNED to match the power you want to make, depending on the cc your using, on what kind of stroke, CR and at the rpm you want it....
There is more factors to take care then only a head porting

m4xwellmurd3r

Yeah like I said I dont like that they cut the guides down so im gonna have new guides installed full length

I did notice they used a fine grit to polish it up, I just wish I had the proper tools to rough it up again since I know a polished surface hurts more than helps.

Ill look again but iirc every port is identical. Dunno what shop did the work but besides polishing the surface it looks like they knew wgat they were doing.

Anyways, its an 81.5mm b18a1 running 10.7:1 compression. Im hoping for 140-150+whp but more is gravy. Hoping ill be able to make power up to around 8k rpm. Itll have a skunk2 pro intake mani.

Eventually itll be boosted but id like playing with it na so I can teach myself to tune some.

Im running a stock head right now and the bottom end I built rips like hell with the way I have it tuned. Around 13:1 afr wot below 3500 then it richens up to about 12.5:1 to the redline. I had to pull a few degrees of timing around 4k-4.5k from some light detonation but now its perfect. I hope to get it on a dyno soon to get a baseline of the engine with a stock head and tune vs ported head with cams

Frankacura

140-150whp is low. you will make more.
I have a B16a that run B18b head ans stock cams and ran my integra 14.3 at 96mph on LS IM shifting 7600rpm thats about 155Whp...
You gonna make around 135TQ @ 5500rpm 175Whp @ 7200Rpm

m4xwellmurd3r

Lol im low ballin my estimates so I wont get dissapointed haha. 175whp would be bad *** though.

edvas1

So there are gains to running a stock p8r head over a pr4 or p75 head? If using a b18b stock bore block which head gasket should I run?

PabloM

non vtec FTW

Frankacura

i dont recomand it on 81mm bore...
Some people did it and burn head gasket,
Mabe Turbo Fire blanket gasket could hold
Or mabe on low CR tuned cold side 12.4:1AFR
I never try it

Frankacura

Sound good...
Is this is your's ?
what are the mods ??

PabloM

nope not mine, it belongs to kbstune.cl from chile, now its b20vtec but with a gain of 10hp

from what i know:

victor x mani, stock rail 440cc injectors, high comp pistons, rods, ported head, crower valve train, golden eagle cam gear, ecu, etc

an2ny888

Frankacura, have a question for you

In your opinion, will a stock vtec head ( be it itr or b16 ), always have better low and midrange velocity than one that has been ported?

My reasoning being, a ported head is going to have slower velocity because of the material that has been removed from it

Frankacura

I An2ny
You are right in certain points
When i port a VTEC head im not oversising the port if its not to go Only Race aplication.
as my port job give you more flow at 300 Lift then what ever the rpm you are the gain is there..
those that get bigger port dont have the nessery velocity to to make torque at low RPM cuz of the low amount of air traveling the bigger port but when you get 2.1L at 9000rpm on stage III cams you must have the velocity so you want bigger ports to bring more air...
but its a big calculate to find is more TQ at less rpm will give me more HP ?
or less TQ at more RPM will be winner, And how long i want my motor to last....
to me More flow at .500 lift for less flow at .300 is a mistake to do.

Frankacura

Stock P8R head flow


P8R non-vtec flowbench results - Honda Forum : Honda and Acura Car Forums