Checking PTV without removing heads??

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Dec 12, 2010 | 11:31 AM

BlackBirds

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From: Fort Wayne, Indiana

Checking PTV without removing heads??

is it possible to check piston to valve clearance without removing the heads? I've read the method using the check spring is done without removing the heads, but you have to put solid lifters in to have accurate measurements, and to put solid lifters in you have to pull the head to replace the hydraulic lifters...

Is there a PTV method that you dont have to remove the heads for? Thanks

Dec 12, 2010 | 11:57 AM

djfury05

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You will need a valve spring compressor tool, checker springs, and feeler gauges. You can keep the hydraulic lifters installed as well as the head. Basically you remove an intake and an exhaust valve spring for a given cylinder and install the checker springs in their place. I'm not sure of the exact process after that but you will depress the checker springs by hand and push the valve toward the piston at TDC for that cylinder and insert feeler gauges in between I think the pushrod and the rocker tip or the valve tip and rocker tip I can't remember which. You are shooting for at least .100 on the intake and .080 on the exhaust valve for clearance. This is very important to check and you had better do it right the first time and be damn sure about it. Otherwise when your car is on the dyno and your getting tuned and a valve head decides to break off because you received your heads at the wrong cc size and now you have to replace the motor.. oh wait that's just me lol. So as you can see I did not check ptv before hand, rather took opinions on if id have enough clearance instead of facts. Like I said it is very important to check and you will save ur *** in the long run if you have any doubt. Good luck man.

Dec 12, 2010 | 11:59 AM

Always2Slow

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You can measure it without a solid lifters you just have to be very careful while measuring and that the lifter doesn't bleed down.

Dec 12, 2010 | 12:42 PM

BlackBirds

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so just don't push very hard on the checker spring so it doesn't bleed down the lifter? Does it matter how long the engine has been sitting?

I've got two checker springs and a dial indicator and I'm all ready to check the PTV, but I realized that I couldn't get to the lifters without taking the heads off, and I remembered everywhere I read they all said you had to use solid lifters.

Dec 12, 2010 | 03:53 PM

djfury05

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If your pushing on the checker spring there should be no tension on the lifter anyways

Dec 12, 2010 | 07:21 PM

BlackBirds

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lol brain fart sorry. so you just make sure the lifter doesn't compress at all when you let the checker spring decompress all the way. I would think the internal spring inside the lifter is a lot stronger then that checker spring... I'm thinking everyone that says you have to use solid lifters when you check ptv with the checker spring method is full of it.

Last edited by BlackBirds; Dec 13, 2010 at 08:44 AM.

Dec 13, 2010 | 05:29 PM

JPH

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You need a degree wheel on front of the motor, to compare where cam timing is, in relation to piston location? Also, shoot for .080/.100 int./exh. Tighter clearances WILL work, but high rpms, valve float, lofting can result in PTV contact down the road.