Keep us posted on how it goes. Good luck.

This is the kind of nightmare I hope I can avoid. Have one guy build it, another guy dyno it. If anything goes wrong then finger pointing.

I would pay to have the second guy reclearance valves=heads after degreeing the cam, just my .02.

Wannabe

Please listen to X-wing.
and by all means,
Bolt on a degree wheel to the crank.
Find TDC thru the spark plug hole (with an adjustable TDC stop) - adjust it so that it touches the #1 piston about 10* before TDC and check it in both directions and zero your crank pointer so that the number is the same from both directions.
Pull a valve cover and borrow a 1" dial indicator on a magnetic base and find your intake centerline. It should be wherever your cam card says (or up to 4* advanced).

That is the ONLY way worth a crap to check the installed position. All it takes is pulling one valve cover, and a little bit of time. You can do it on an engine stand, in the bed of your truck, in the boat - it is really NOT a time consuming job.

Crank keyways can be "off" a little bit. Stock timing marks on the timing cover can be "off" a little bit. Cams can be ground "off" a little bit. Timing sets can be "off" a little bit.

Don't trust the freaking timing marks in a situation like this.

No "builder" who is worth handing a dollar bill doesn't have a degree wheel and some knowledge on how to use it.
It's really as easy as I said above.

MC

WOW!!!!! A fresh set of eyes is whats needed. I agree with degreeing the cam. You can pick up a wheel from summit /jeggs and and a dial indicator for not alot of cash. Its not overly complicated.

I say that the ACTUALL V/P clearance is next to 0.000 Been there done that. SAME RESULTS

One other idea, I have seen people misadjust their valves with no oil in the lifters.The lifters pump up some of the valves may not even quite close. At that point you could get contact. Your piston to valve clearance would have to be pretty tight for this to happen. What was the clearance when the machinest clayed the pistons.

I always used the light spring method with a dial indicator + or - 10 degrees from TDC.

lets think this out,without knowing the part number of the pistons there is no way to know if they are flat top or have a small dome,im assuming they have a small dome to achive 9.3 to 1 compression ratio,this is assuming the heads are not angle milled.your cam is somewhat mild so there should be plenty of piston to valve clearance if the cam is installed correctly.three things could be causing your problem,1 valve to guide clearance not sufficent 2 cam installed incorrectly 3 weak valve springs not pulling the valve back on the seat causing contact with the piston.at this point if this engine was in front of me i would remove heads and check ALL valve to guide clearance,[2] degree camshaft to make sure it is installed correctly[3]check valve train geometry[4] check valvespring pressure on the seat[5]check piston to valve clearance useing a solid lifter so there is no bleed down.these are all things that a competent shop can and should do.even though this engine is close to stock all these things still need to be done.after 2 failures maybe it is time to find a different shop to do the work.hope this helps.

Fixed it
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