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On a brand new rebuild (1990 302), I am leaking compression past the intake valve into the intake. Heads were reconditioned with valves and guides being ground. I observed this while rotating the engine by hand while tape was over the intake. I have two cylinders bleeding compression into the intake. I observed pushrods at the point of it bleeding off and both valves are completely closed when this happens. Should I be concerned, or will they seal up once it fires off the first time? Let me know if I need to take this up with the machine shop who built my heads.

Thanks,
Greg
 

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A million years ago, I had a head reconditioned, and the way they tightened up the valve guides was to knurl them (the guides). Anyway, they were too aggressive with the knurling and the valves were so tight in the guides that they would actually stick somewhat open even against the valve spring pressure. We had to pull the springs and valves and ream the valve guides a little to open up the clearance.

We took the rocker arm off and pushed on the valve with the wooden part of a hammer handle. Pushed down and some didn't come all the way up. We then pulled the valve spring and manually pull/pushed the valve up and down. They should move in the guides pretty easily.

I would make sure that that cylinder was at TDC, so if the valve is loose in the guide, it won't fall into the cylinder.

Seems to me that the valve stem clearance might get tighter when the engine warms up, if the guides are too tight now, they might get worse if you run the engine.

Just my 2 cents.

Good Luck
 
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