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Discussion Starter #1
Degreed the cam and checked piston to valve clearances for my 351W. With a dial indicator the closest the intake got was .156" at 20 degrees ATDC while the exhaust was .251" right at TDC. With clay the intake was .165" and .075" radially. The exhaust was .230" and .165" radially. I think the intake radial clearance might be a little tight.

A tip of the hat to Howard's Cams. Everything checked out with the cam card right on the money.
 

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Degreed the cam and checked piston to valve clearances for my 351W. With a dial indicator the closest the intake got was .156" at 20 degrees ATDC while the exhaust was .251" right at TDC. With clay the intake was .165" and .075" radially. The exhaust was .230" and .165" radially. I think the intake radial clearance might be a little tight.

A tip of the hat to Howard's Cams. Everything checked out with the cam card right on the money.

These numbers are plenty good.


Intake can get .080 vertical and .060 radial. It doesn't expand as much.



Exhaust needs a little more at .100 vertical and .080 radial. Exhaust runs a lot hotter has worse stem/guide lubrication thus wider initial clearance and faster wear. All this adds up to giving the exhaust valve more working space.


Piston bore clearance gets in the act, high silicon pistons with tight skirt clearance whether cast or forged rock less that low silicon cast and especially forged with wider clearances rock about the pin and can use a little extra valve clearance.



Bogie
 

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Discussion Starter #4
They're high silicone, cast pistons with stock clearances so should be good to go. Thanks guys. I'm going to button it up.
 
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