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crazechris85 10-07-2012 05:38 PM

valve clearence
 
I have a 60 over 350 i bought a set of used bowtie phase 2 heads comp xe 268 cam 1.6 full roller rockers. pistons hit valves need help on what to do i have around 600 in heads im trying to stay away from fly cutting pistons

crazechris85 10-07-2012 05:57 PM

I took the 1.6 rockers off an adjusted the valves they cleared so I primed the oil pump and they hit and I should say I picked up the heads real cheap all the valves where bent so I put new valve train in the heads the pistons are stock style dish piston

Richiehd 10-07-2012 07:23 PM

So you went to a 1.5 rockers and valves still hit? What head gasket you using? I think your only choice is thicker head gasket or smaller cam. Somone must have machined the heck out of those heads.

BOBCRMAN@aol.com 10-07-2012 07:25 PM

Priming the oil pump should have nothing to do with piston/valve clearance. Your cam is installed incorrectly. No way a correctly installed .450 lift cam with short duration is going to hit

Silver Surfer 10-07-2012 07:28 PM

Use 1.5:1 rockers
Use thicker head gasket
Advance or retard the cam depending on what valve is hitting

adantessr 10-07-2012 07:29 PM

Quote:

Originally Posted by BOBCRMAN@aol.com (Post 1597008)
Priming the oil pump should have nothing to do with piston/valve clearance. Your cam is installed incorrectly.

I am with you , Bob .

crazechris85 10-07-2012 07:36 PM

It's only the exhaust valve that hits the cam is correct I checked three times I think the heads are zero deck and the blocke was decked .010 but delima is if I have zero clearance now if I get the pistons cut to give me .080 clearence is that to
Much for the pistons I have never seen 488 lift hit pistons but the heads are the in known I was thinking of just pulling the heads back off an selling them an getting a set of dart iron eagles

crazechris85 10-07-2012 07:43 PM

I'm using stock felpro gaskets

crazechris85 10-07-2012 07:47 PM

So the exhuast valve is hitting what way would I go advance or retard cam timming and about how much would that do for the clearance I can only 6 degres. Eather way???

BOBCRMAN@aol.com 10-07-2012 07:50 PM

The heads would have had to been milled .100" to get the valves even close to the pistons. Of course then nothing else would fit.

You probably have a three way timing set installed at the wrong position.

I just had a customer, two months ago, with similar problem.. Went thru 16 bent exh valves, eight broken studs and 12 pushrods. Not to mention the gasket sets.

I told him the first time what the problem was. But, customer is always right. Hard headed and stubburn too..

crazechris85 10-07-2012 07:55 PM

I have it set at 0 Stright up and even checked the gears with the old ones they were the same the heads came off a drag car they 2.08 an 1.60 the pistons have valve reliefs but is it possiable the the reliefs are not big enough around??

adantessr 10-07-2012 07:57 PM

Quote:

Originally Posted by crazechris85 (Post 1597025)
So the exhuast valve is hitting what way would I go advance or retard cam timming and about how much would that do for the clearance I can only 6 degres. Eather way???

You want to advance the cam to get the exhaust valves to close sooner. If you want to know how much difference it is going to make, put a dial indicator on the valve end of a rocker, and turn the engine 12 degrees ATDC ( this would be 6 degrees on the cam ) and see how much that brings the rocker up

cdminter59 10-07-2012 07:57 PM

valve clearance
 
Sounds like the first thing you should do is have them heads CC'ed. What thickness head gasket are you using? Use a .041 head gasket and place some clay on top of the piston. Bolt the head on to check the Valve to piston clearance.

crazechris85 10-07-2012 08:12 PM

I'm using a .041 head gasket no need to measure clearence I already know I have 0 clearence the vavles are contacting just turning over by hand lol the heads have been decked so far that the tip of the intake valve is even with the deck of the head

vinniekq2 10-07-2012 08:30 PM

can you post a picture of the heads?something is way wrong.If these are race heads,what do they flow? what size are the intake runners?


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