Some basic questions
Thread Starter
Joined: Feb 2008
Posts: 1,265
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From: Bolton Masshole
Some basic questions just some random questions here:
How does one check PTV clearance without removing the heads? Is this even possible?
Also, as i read through some of these threads of guys with PTV clearance issues, some have suggested flycutting the pistons. How is this done?
How does one check PTV clearance without removing the heads? Is this even possible?
Also, as i read through some of these threads of guys with PTV clearance issues, some have suggested flycutting the pistons. How is this done?
TECH Addict
Joined: Sep 2009
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From: PA/MD
I wedged a .100" shim between the rocker tip and valve tip then turned my engine over by hand to check mine.
They make a fly cutting bit that slides up into the valve guide, then hooks to a drill, its not hard, but the heads have to come off
They make a fly cutting bit that slides up into the valve guide, then hooks to a drill, its not hard, but the heads have to come off
The best way is to actually remove the heads.You can use the clay method. It involves putting clay on your piston, bolting your head back up, and cycling your engine a few times by hand. Measure the impression, and you have your clearance. Mark's way will work to give you a minimum, but will not tell you the exact clearance.
Why so afraid to remove the heads? It is just the cost of gaskets and bolts, and if you go with ARP, you only need to buy the head bolts once.
Why so afraid to remove the heads? It is just the cost of gaskets and bolts, and if you go with ARP, you only need to buy the head bolts once.
Thread Starter
Joined: Feb 2008
Posts: 1,265
Likes: 18
From: Bolton Masshole
haha im not afraid to remove the heads. hell right now i dont even have a car as i just sold my ws6. But im looking for the right LS1 car right jnow and im hoping to do heads/cam asap.
Thread Starter
Joined: Feb 2008
Posts: 1,265
Likes: 18
From: Bolton Masshole
so how does this let you know if you have PTV clearance issues or not?
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Staging Lane
Joined: Jul 2005
Posts: 96
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From: Stanwood, Wa.
I am at lunch at work right now, so I don't have time to search and write it all down. With light check springs on cyl. no. 1 valves, mount the dial indicator so it contacts the valve spring retainer, and close to parallel to the valve. Check with 15 deg BTDC and 15 deg ATDC, they say check every 2 deg by rotating the rocker until the valve touches the piston and reading the distance on the dial indicator. Crane cams web site has a better description if you have time to search.
http://cranecams.com/pdf/20e.pdf
http://cranecams.com/pdf/20e.pdf
Last edited by 99C5Coupe; Mar 24, 2010 at 02:58 PM.
TECH Addict
Joined: Sep 2009
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From: PA/MD
No disrespect taken here lol.
With the shim wedged between the valve stem and rocker the valve opens .100 futher than it would without the shim.
I forgot to add the check springs... I used them so the lifters would not collapes. I think they were around $2 at Lowes.
Best way, no but for a quick check without pulling the heads it works. Also if a .100 shim had clearance I definately had .800
With the shim wedged between the valve stem and rocker the valve opens .100 futher than it would without the shim.
I forgot to add the check springs... I used them so the lifters would not collapes. I think they were around $2 at Lowes.
Best way, no but for a quick check without pulling the heads it works. Also if a .100 shim had clearance I definately had .800
Thread Starter
Joined: Feb 2008
Posts: 1,265
Likes: 18
From: Bolton Masshole
No disrespect taken here lol.
With the shim wedged between the valve stem and rocker the valve opens .100 futher than it would without the shim.
I forgot to add the check springs... I used them so the lifters would not collapes. I think they were around $2 at Lowes.
Best way, no but for a quick check without pulling the heads it works. Also if a .100 shim had clearance I definately had .800
With the shim wedged between the valve stem and rocker the valve opens .100 futher than it would without the shim.
I forgot to add the check springs... I used them so the lifters would not collapes. I think they were around $2 at Lowes.
Best way, no but for a quick check without pulling the heads it works. Also if a .100 shim had clearance I definately had .800
TECH Addict
Joined: Sep 2009
Posts: 2,481
Likes: 5
From: PA/MD
I removed the valve springs on number 1 intake and exhaust and replaced them with "check springs" I got at Lowes hardware store. (They were small soft springs about 3" long and 3/4" across)
With these springs in you can push the all the way open with your finger and slide the shim in with the rockers bolted down
With these springs in you can push the all the way open with your finger and slide the shim in with the rockers bolted down
