i want to buy this set of crower stage 3 cams for my h23a vtec bluetop,,, do i need to buy roller rockers with this size lift cam or modify the stock rockers? ive heard different stories i just wanna make sure i get my ducks in a row cause this motor is in my dirt race car and i dont want it down and apart for too long. or does anyone recommend another set of cams, my head is milled to the max, some porting has euro intake, my rpm range at track is between 4000-8000rpm im either half or full throttle all the time.

 

few things...

there are much better cam options than crower especially for your operating rpm range.

no you wouldn't need rollers but I doubt you have enough valve clearance to run any aftermarket cam in that bluetop if you have milled the head. they don't have much clearance to begin with stock. unless of course you have already built the bottom end with aftermarket pistons having deeper/wider valve pockets.

If you have clearance I would suggest skunk2 pro1s. those crowers along with most other cams are gonna cost you a ton of midrange power. yes you will actually lose power with those cams at your operating rpm.

also I would not have ported the cylinder head for that rpm range. a good valve job would have been the way to go. well the good news is you have the right intake manifold for your application

 

you really do have to keep your piston to valve clearance in mind.
you wont need rollers but those cams do require upgraded dual springs.
PN: BC0030

 

im running the crower3 in my daily (came with the car). i had to play with the cams a lot to get even a half decent graph on a stock h22a bottom. the euro helped the power in midrange but other cams would be a much better option. id go for the pro1 as well. you should have plenty of valve clearance to make a decent graph.

 

what makes you say this? have you ever checked p2v on a bluetop h23vtec?

from my experience p2v is tight to begin with on stock cams and he said he milled the head to the max.

just curious why you believe he will have plenty of clearance?

reason I ask is a friend of mine has this same engine completely stock and had p2v contact bending the valves simply by missing a few shifts @ the track. I have never measured p2v on it since it hasn't gone back together yet but im very interested in knowing if anyone has actually measured p2v on this engine using dial indicators and a degree wheel (not clay) with stock cams and/or aftermarket cams.

 

I know on my build, with PRO1 cams, and stock valves and block/ head height I was really close on the valve reliefs, but that was the closest point. Unfortunately I haven't been able to buy dials and fixture yet, so no super exact numbers.

My build is 95 mm crank, H23A1 rods, and H22A pistons, so the H23A with the shorter rods, would have an extra .020 of clearance, before milling is taken into account right?

 

we are talking about a jdm h23vtec.

assuming its stock since the op didn't list it as being built...

 

hrmm.. sounds like OP needs to check some clearences or go with something else.