Valve reliefs vs shaving tops or both????

DISTURBED said:
I always keep a good crushed gasket around just for checking piston to head and PTV clearance. Might be a good thing for guys to hang on to instead of tossing them in the trash
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That's actually how I checked my measurements. It's easy to do
 
Okay I'm going to measure a few more times to make sure I have my numbers on and then I will send these dudes over to my guy for him to cut reliefs and do a little shaving, would it be best to have him open up the bowls a little while hes got them or leave them alone?
 
Yea I feel I would be safe getting .020" cut off leaving me with .020" protrusion on them from what I have learned here, do I need to have around .040" for the PTV clearance as well? I doubt I will have any problems with .120" reliefs but just for my knowledge I think it would be good to know what clearance is used usually when building an engine for this. Thanks to all that have replied and got me in the right track, I'm hoping to be wrapping up the engine in the next couple months and will post some pictures of the setup and truck when I get started on it.
 
SmokeSmacked02 said:
Yea I feel I would be safe getting .020" cut off leaving me with .020" protrusion on them from what I have learned here, do I need to have around .040" for the PTV clearance as well? I doubt I will have any problems with .120" reliefs but just for my knowledge I think it would be good to know what clearance is used usually when building an engine for this. Thanks to all that have replied and got me in the right track, I'm hoping to be wrapping up the engine in the next couple months and will post some pictures of the setup and truck when I get started on it.
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Yes, I wouldn't run any less then .040 ptv
 
97rada said:
Isn't closer to .060-.080 suggested
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Depends on the application. We ran 8k rpm gas race engines at .040 ptv and had no issues. On street and mild builds I run around that. The higher hp stuff I will open it up for insurance
 
SmokeSmacked02 said:
Yea I feel I would be safe getting .020" cut off leaving me with .020" protrusion on them from what I have learned here, do I need to have around .040" for the PTV clearance as well? I doubt I will have any problems with .120" reliefs but just for my knowledge I think it would be good to know what clearance is used usually when building an engine for this. Thanks to all that have replied and got me in the right track, I'm hoping to be wrapping up the engine in the next couple months and will post some pictures of the setup and truck when I get started on it.
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DISTURBED said:
Yes, I wouldn't run any less then .040 ptv
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97rada said:
Isn't closer to .060-.080 suggested
Click to expand...


DISTURBED said:
Depends on the application. We ran 8k rpm gas race engines at .040 ptv and had no issues. On street and mild builds I run around that. The higher hp stuff I will open it up for insurance
Click to expand...


I think there is some terminology getting mixed up here. Piston to valve vs piston to head.
 
When I was discussing .060-.080 I was talking PTV. What you discussed earlier was PTH
 
I was originally referring to PTH clearance and then turned to wanting to know if the measurement would be about the same on PTV clearance.
 
I like to see .040 Piston to head. On hp builds I like to see the valve to piston clearance at .07 intake, and .085 exhaust. Some guys run them closer, but I don't like to fix stuff. Also agree just cut the valve reliefs if you want your engine to run right.
 
You're tossing around billet rods, but I think you'd be better off running a set of forged pistons on the peened 12v rods. I run the pistons nearly flush with my Ross pistons and 12v rods.
 
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