my current setup is an 81.5x95mm b18c1 block around 11.6:1 compression with an unported stock valve b16 head, supertech valve springs and retainers with blox stage 3 cams, stock pr3 cam gears and an edelbrock performer x manifold and 70mm TB with a comptech race header.

now my question is would it be worth it to swap the head to a stock port/valve JDM ITR head with buddy club spec IV cams, manley springs and retainers and toda cam gears? or would the power gains not be worth it?

also would there be any power to be gained from adjusting the cam gears? or could i just stick with stock ones?


here are the cam specs for those of you dont have them memorized haha

buddy club Spec IV
Intake Cam: 12.3mm lift 306* duration
Exhaust Cam: 11.8mm lift 302* duration

blox Stage III
Intake Cam: 12.8mm lift 272* duration
Exhaust Cam: 11.9mm lift 280* duration

and just curious, are the duration measured at different valve lifts for the blox cams than the buddy clubs? or does the duration just differ that much?

 

With that much stroke, I would definitely look into a ported head. I didn't even know you could run stock gears with those cams.

 

the car has a Y21 with 4.78 FD

 

omg thats alot of duration! bet this thing hauls *** with that gearing. I would go 84mm with a ported head and spec 4's

 

yeah i wish i could sleeve it to 85-86mm

 

if your investing all this money, you might as well or at least go a bit bigger and do the css, it pretty cheap.

 

Those numbers are advertised numbers, not real, .050 numbers or what the motor actually sees.

Those are the .030 hype numbers.

 

thanks, good info to know

 

Yep so look for something like say pro 2 or pro 3 or even m24xx. Something that's gonna perform in and out of vtec. Pro series is usually your best bet.

Oh and yes stock itr head is an improvement over a stock gsr/b16 head btw. I like my itr head :-D

 

I would get the ITR head, sell the cams and get some Pro 2's. Whatever cam you go with you MUST degree them in. Its an extra cost and takes a little time, but the power gains are well worth the extra work. You will also want to upgrade the lost motion assemblies to the spring type to make sure there is enough travel to let the big cams go around.

 

I agree with him(^^^) partially. Yes on degreeing whatever cams you get. But I wouldn't waste my money on a itr to run it stock. I would get another b16 head and have a full port job done. Don't spend the $ just because its a ITR. Its only polished between the guide and seat. B16 and ITR heads are the same casting.

 

The seat angle and throat angle is Better on the ITR head as well as the deshrouding it has. Its worth the mod. The port you refer to is actually called bowl blending and gives it better high lift flow.