Valve Clearance?
Thread Starter
Pro
Joined: Apr 2005
Posts: 591
Likes: 7
From: Batavia IL
Valve Clearance?
Gonna try this question out with the c-3 guys....
I am putting together a 383 and had a question about clearance for the valves. I am considering using a mechanical roller cam that has about .580-.6 lift. I am almost positive that there will be issues with the valves hitting the pistions due to the unconventional layout of the valves in my heads. My heads are Trickflow twisted wedges. What I wish to know is, is there a tool I can use to grind proper valve reliefs into my pistions so that I will have enough clearance? such as a cutting bit the same size as the valve and bolt the head on and lower it onto the piston to grind the reliefs. maybe I can just sharpen a valve and use that as my cutter. Is this a smart way to do this?
I am putting together a 383 and had a question about clearance for the valves. I am considering using a mechanical roller cam that has about .580-.6 lift. I am almost positive that there will be issues with the valves hitting the pistions due to the unconventional layout of the valves in my heads. My heads are Trickflow twisted wedges. What I wish to know is, is there a tool I can use to grind proper valve reliefs into my pistions so that I will have enough clearance? such as a cutting bit the same size as the valve and bolt the head on and lower it onto the piston to grind the reliefs. maybe I can just sharpen a valve and use that as my cutter. Is this a smart way to do this?
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I have seen a tool for this and used one once. It looks like avalve and has cutting grooves in it. Measure the valve to piston clearance first before you start grinding on the pistons. You want .100 on the intakes and .125 on the exhaust to be safe. You can go tighter but these are safe numbers.
Burning Brakes
Joined: Apr 2004
Posts: 847
Likes: 0
From: Des Allemands LA
There is a setup you can use that fits where the valve normally would in the head. The head is mocked up on the block and a drill can be used to cut the valve reliefs, the valve guide is used to ensure everything is removed where the valve will actually ride. It also has a stop on it used to ensure you don't cut too much. It's actually pretty straight forward but is a little bit of a pain and takes some time, but in this area I don't mind taking my time.
ltlevil
ltlevil
Race Director
Joined: Jan 2000
Posts: 13,015
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
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2017 C2 of Year Finalist
You can get the tool from Iskendarian. Works well..takes some time...but works nice.
JIM
JIM
