checking ptv
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Staging Lane
Joined: Jul 2012
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From: yankton SD
checking ptv i need to check ptv clearance on my 4.8 before i have my heads milled so i can be sure i dont have issues. i plan on taking .040 off of them and using an .041 head gasket if i can. my question is how do i measure for what pushrods to get before i have the heads milled? can i just snug the head down with a few bolts without a gasket to measure? thanks
That will work. You can either wait and measure for pushrods after all the work is done and heads are on, or you can do it the same time your measuring ptv. Just snug it down with a few bolts without the gaskets and check ptv, add in your gaskets thickness and subtract your mill on the heads. Same for pushrod length.
Thread Starter
Staging Lane
Joined: Jul 2012
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From: yankton SD
I need the correct length pushrods to properly check ptv don't I? I am assuming the stock length pushrods will be to long by the time I mill the heads and put in the thinner gasket. Thanks for the help I've built motors before but I've never checked ptv or pushrod length before
What "nuts" said^^^
Also, you don't need the pr's to check PTV. Use lite wt springs, a dial indicator, a degree wheel. Check at 10* increments BTDC and TDC...
As mentioned, check the pr length after all's done being machined and assembled.
Also, you don't need the pr's to check PTV. Use lite wt springs, a dial indicator, a degree wheel. Check at 10* increments BTDC and TDC...
As mentioned, check the pr length after all's done being machined and assembled.
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Thread Starter
Staging Lane
Joined: Jul 2012
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From: yankton SD
ok i think im still missing something here. how can you check ptv clearance without pushrods? also i dont have a degree wheel or dial indicator so i was just going to use the clay on the piston method and measure that way. sorry for all the questions. is there a thread explainig how to check ptv somewhere on here? i searched with no luck. thanks
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Verdad Gallardo ok i think im still missing something here. how can you check ptv clearance without pushrods? also i dont have a degree wheel or dial indicator so i was just going to use the clay on the piston method and measure that way. sorry for all the questions. is there a thread explainig how to check ptv somewhere on here? i searched with no luck. thanks
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
With a checker spring you shouldn't need a solid pushrod. And plus 1 for old gasket. However factor in whether you are going back with the same gaskets during rebuild. Not all HG are the same thickness.
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From: Huntsville, Alabama - SA, TX is home
Yea but I believe you'll have to use a gasket since the piston usually comes out the hole a lil. that'd make it hit the head without a gasket.
Thread Starter
Staging Lane
Joined: Jul 2012
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From: yankton SD
So you're shaving off 0.040 and ~0.012 thinner on the head gasket? Total of ~0.052"
I'd double check manifold to head mating surface, making sure the intake manifold isnt trying to fold on top of the engine.
I'd double check manifold to head mating surface, making sure the intake manifold isnt trying to fold on top of the engine.
