Hotrod God

I was wondering if anyone could tell me my P/V clearance is gonna be ok with this set up?:


AFR 205 heads (uncut), Comp cam w/ .571" intake, .573" exhaust, 228 intake @.050", 230 exhaust @ .050", all using 1.75:1 roller rockers and 7.400 push rods and Comp R lifters. With the rockers I figured I would get about .588" intake and .590 exhaust. Also have 2.02 intake valve dia. and 1.60 exhaust valve dia.

PREDATOR-Z

IMO would run 1.70 (like Jesel) rockers and get Crane roller lifters instead of the comp "R".

Hotrod God

I have already purchased the parts listed above. Thanks for your opinion though. BTW the LSA on the cam is 112. I don't know if that will make a difference.

PREDATOR-Z

Oh it will work fine, provided you get the right preload on those lifters. I would recommend .008>.010 cold.

Hotrod God

Yeah thanks for the preload tip. I had a post that you replied to earlier on that question. Heh, now I'm concerned weather or not My 7.400 pushrods are going to be too long.

bigdsz

iTrader: (1)

I just ordered a Comp 228/230 .588/.592 112 +2. Valve lift @ TDC 110 ICL .105", 112 ICL .099". Hope this helps.

Hotrod God

So do you think you are going to have clearance problems? I'm kinda still a noob, but I assume that 112 +2 means you have your timing set 2 degrees advanced? Also I assume ICL = Intake Center Line, but what is the measurement of .105" and .099" for?

JNorris

iTrader: (4)

What size valves are you running?

Thanks

John

bigdsz

iTrader: (1)

I have Absolute Speed 5.3L heads with 2.04 intake and 1.575 exhaust valves.The .105" and the.099" are valve lift at TDC. You can check clearance before the cam install by bringing a piston to TDC taking the valve springs off, and letting the valves drop down to rest on the top of the piston.Then put a dial indicator on the top of the valve stem, zero it out and then lift the valve back up. Hopefully the reading will be .200"+. Subtract the .99" valve lift and you have over .100" clearance, plenty of room. What's nice is that these measurements tell you in advance if the cam will fit, but you still want to degree the cam ater the install particularly at 10* BTDC for exhaust and 10* ATDC for intake. When doing the valve drop test there should be .080" intake and .100" exhaust minimum clearance. I only had .177" total on my intake, with .239" exhaust.

bigdsz

iTrader: (1)

Also, FWIW if you are changing lifters you should mike the head deck thickness where the head bolt by the exhaust port goes through the head. Unmilled heads have a thickness of 1.615". Even if you think you know how much the heads have been milled, it's a good idea to check this measurement.

HAMRHEAD

iTrader: (8)

You will not have a P to V clearance issue with that set up. The 112 + 2 means the cam has 2degrees of advance ground into it.

bigdsz

iTrader: (1)

You will not have a P to V clearance issue with that set up. The 112 + 2 means the cam has 2degrees of advance ground into it.


Even with a 110 ICL I'll have plenty of room? It is a XER lobe.