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Why are you measuring on the intake valve? The exhaust valve is what the piston chases on it's way back up. What thickness head gasket, what lash are you using?
 

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Discussion Starter #4
Because my exhaust valve has .130 clearance, its fine. I am worried about LATERAL clearance on my intake valve. The side of the valve it close to the side of the valve pocket. It looks as though it has .050 ish clearance. I just dont wanna fuck up. These are new pistons. Reliefs are different.
 

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OK, now I'm following along. I wouldn't think you're going to get that much expansion of the relief area when it heats up to create an issue? I'm sure someone has experienced that and can chime in and give a better answer than mine? Worse case scenario pull them out, and have the relief cut back a few thousandths before you do your final assembly?
 

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Discussion Starter #6
Well I wanted to assemble it today and tomorrow, this has me held up.
 

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Why are you measuring on the intake valve? The exhaust valve is what the piston chases on it's way back up.
Doesn't the intake valve "chase" the piston down the bore on the intake stroke, sometimes having more clearance issues after TDC with some bigger cams?
 

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What is the piston to wall clearance?

This is interesting and something I haven't had to consider in the past. What is the apication? Street car? Power adder? Knock sensors? ECU?
 

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a good "SAFE" rule of thumb on valve pockets are 0.100 OD larger than the intake valve diameter or 0.050 per side -----
 

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if its not assembled yet......dont chance it, id get them cut larger, Mine were about .030, i put it together and guess what?? every intake left a witness mark on each piston and it was getting oil in the puke tank. Why chance it?? .050 is prob ok, but after my exp i had them all opened up another .050
 

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Take an old valve and cut the tulip off...then sharpen it. Place threw the guide and make a center mark on the piston. Then measure to the edge of the valve relief
 

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Discussion Starter #15
Its together, a buddy came over and looked at it says "its good". Nate this is an all motor streetcar. The one in my sig.
 

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put in a sample valve that has a .100" diameter larger diameter ,

you have to time the cam and set up all the necessary things such as geometry and pushrod length ETC...FIRST.
 

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Last time I ran one that close......I had Custom pistons and bent Valve when I took it back apart ;)
 
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