piston to valve clearance

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Mar 4, 2004 | 04:00 PM

jsutton

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From: Northeast LA

piston to valve clearance

i am rebuilding an 84 302 block and putting my 77 D7OE heads on it. i want to put a different cam in. it has a C4 auto and is a two wheel drive. I know from reading other posts that with stock springs the max lift is .5 but i plan on replacing the stock springs. my question is what is the max lift before i have to worry about checking piston to valve clearance. i was looking at a melling cam with .520 lift on the exhaust. i don't want too much of a radical cam but i want people to be able to tell by the idle i did a cam swap. this is not my daily driver and i never tow anything. any help would be greatly appreciated!

Thanks

jason

77 f100
two wheel drive
long bed

Mar 5, 2004 | 09:25 AM

shifty

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you should check piston to valve clearence when ever you go to a higher lift cam

Mar 6, 2004 | 12:05 AM

Capone

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From: Monterey bay area

what sized valves?

Mar 8, 2004 | 06:31 AM

jsutton

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Joined: Sep 2003

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From: Northeast LA

It is the stock size valves. i think the haynes book that i have says that they are 1.90 on the intake and 1.84 on the exhaust, but i will have to check when i get i home tonight to make sure. I will repost the correct numbers if I'm wrong.

Thanks,
Jason

77 F 100
long bed

Mar 10, 2004 | 10:40 AM

jsutton

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From: Northeast LA

i checked in the haynes book and i was wrong it doesn't give the valves size, so i don't know what size they are. i tried to call autozone and the ford dealer, but neither said they could tell me what size valves came in D7OE heads. i think i will just stick with a cam under .5 lift and check the clearance to be safe. Thanks for the input though. i appreciate it.

Thanks again,
Jason

Mar 15, 2004 | 02:32 AM

Capone

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From: Monterey bay area

If I recall correctly you have 1.85/1.46 combo....and .515-.525 would be up there as far as what you could push....piston to valve clearance wise...

another thing to consider is the rocker ratio.....I would run 1.6

then the gakset compressed thickness....

Best way to check piston to valve clearance is to get a slid lifter....press some small globs of clay on the valve reliefs and tighten the heads down without gaskets...and turn the assembly.....onece a revolution is complete disassemble and check clearances....with a micrometer...