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Warhead · 05-02-2008, 01:44 PM

Valve to piston clearance is NOT an issue with the Oldsmobile engines like they are Chevrolet's, because the valve angle on the Small block chevy is at 23 degrees, leaning the head of the valve at an angle that can interfere with the piston. That's why they have pockets in the pistons.

Oldsmobiles have a 6 degree valve angle that does not come near as close as the chevy does. While the angle does not promote airflow as well as the chevy, clearance is hardly ever an issue, unless you run massive cam (250@.050 or more, with .580+ lift). IT NEVER hurts to double check it, however.

Those pistons do not come with valve notches, but if there is a clearance issue, Isky makes a great tool for the DIY guy.

Is it too late for you to get a set of 2 inch intake valves?

600 holley? How about a nice 735 quadrajet?

BTW, #5,#6,#7,& #7a's will never, ever, ever,ever,ever,ever come from the factory at 64cc's, unless someone has milled them at least .040 inch.
They come in at 68cc's at the barest minumum.....FACT.

VERY good piston, make sure your machinist gives it at LEAST .004 piston to wall clearance, and have him pin fit the pistons. If you don't, it may cost ya.

Jim in Phx.

05-02-2008, 01:44 PM	#3 (permalink)
Warhead Senior Member Join Date: Mar 2008 Posts: 87	Valve to piston clearance is NOT an issue with the Oldsmobile engines like they are Chevrolet's, because the valve angle on the Small block chevy is at 23 degrees, leaning the head of the valve at an angle that can interfere with the piston. That's why they have pockets in the pistons. Oldsmobiles have a 6 degree valve angle that does not come near as close as the chevy does. While the angle does not promote airflow as well as the chevy, clearance is hardly ever an issue, unless you run massive cam (250@.050 or more, with .580+ lift). IT NEVER hurts to double check it, however. Those pistons do not come with valve notches, but if there is a clearance issue, Isky makes a great tool for the DIY guy. Is it too late for you to get a set of 2 inch intake valves? 600 holley? How about a nice 735 quadrajet? BTW, #5,#6,#7,& #7a's will never, ever, ever,ever,ever,ever come from the factory at 64cc's, unless someone has milled them at least .040 inch. They come in at 68cc's at the barest minumum.....FACT. VERY good piston, make sure your machinist gives it at LEAST .004 piston to wall clearance, and have him pin fit the pistons. If you don't, it may cost ya. Jim in Phx. Last edited by Warhead : 05-02-2008 at 01:51 PM.