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PTV clearance issues

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Old Jun 7, 2013 | 06:23 PM
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Default PTV clearance issues

I put the 233/239 cam in, got the cam dot to dot, put head gasket on, put head and tightened it down. Slid stock 7.400" pushrods in, tightened rocker arms, then turned motor over and was given 0 clearance. I didn't get "held up", and I made 2 full revolutions, but it ate right through the clay and put really small indentions in my pistons.
-I am using checker springs

I decided I would put my stock cam back in and try it, it had clearance on the intake side but not exhaust.

Can anyone tell me what I may be doing wrong?
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Old Jun 7, 2013 | 06:53 PM
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If you are using checker springs with 7.400 pushrods your probably not collapsing the lifter any and its holding the valve open. Only run the rocker bolt down until you have zero lash and try it.
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Old Jun 7, 2013 | 06:58 PM
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Originally Posted by badassracing
If you are using checker springs with 7.400 pushrods your probably not collapsing the lifter any and its holding the valve open. Only run the rocker bolt down until you have zero lash and try it.
Zero lash meaning tighten it just until rocker is snug with pushrod?
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Old Jun 7, 2013 | 07:16 PM
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Yes try that and see what happens. If you watch the valve and tighten the rocker down the whole way I bet its opening the valve.
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Old Jun 7, 2013 | 07:20 PM
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Originally Posted by badassracing
Yes try that and see what happens. If you watch the valve and tighten the rocker down the whole way I bet its opening the valve.
OK will do! Once if this does solve my problem, once my new springs are installed, I wont have a problem with this 0-lash thing will I? I'll just be able to tighten my rockers and be ready to roll?
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Old Jun 7, 2013 | 07:23 PM
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Your pushrods may be too long for checking ptv. Like mentioned you need zero lash to check no more. Than measure for the correct length pushrods
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Old Jun 7, 2013 | 07:27 PM
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Originally Posted by tyler99
OK will do! Once if this does solve my problem, once my new springs are installed, I wont have a problem with this 0-lash thing will I? I'll just be able to tighten my rockers and be ready to roll?
You'll be good to go once you put the springs on.
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Old Jun 8, 2013 | 12:05 AM
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Originally Posted by tyler99
OK will do! Once if this does solve my problem, once my new springs are installed, I wont have a problem with this 0-lash thing will I? I'll just be able to tighten my rockers and be ready to roll?
It's not quite that easy...You need to measure for the correct length + pre-load. How do you know 7.4 is the correct length?
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Old Jun 8, 2013 | 12:55 AM
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You need an adjustable pushrod.
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Old Jun 8, 2013 | 06:28 AM
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Read this Tyler, the document is still a draft but it should help you.

http://www.scribd.com/doc/137049285/...RAFT-20-Apr-13
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Old Jun 8, 2013 | 06:29 AM
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Originally Posted by 01ssreda4
You need an adjustable pushrod.
Highly doubt factory push rods will work. Buy you a comp checker, just 20$ from TSP.
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Old Jun 8, 2013 | 09:31 AM
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Originally Posted by 01ssreda4
You need an adjustable pushrod.
I actually have one. Do I want to use it as my pushrod when I check for ptv? Should I slide it in, tighten the rocker just until it begins to push my checker springs down, then turn the pushrod until it is snug with the rocker and that's the size I need?

I've never done anything to a car before so I'm just learning as I go.
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Old Jun 8, 2013 | 11:46 AM
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Originally Posted by tyler99
I actually have one. Do I want to use it as my pushrod when I check for ptv? Should I slide it in, tighten the rocker just until it begins to push my checker springs down, then turn the pushrod until it is snug with the rocker and that's the size I need?

I've never done anything to a car before so I'm just learning as I go.
Collapse the push rod checker, install it, tighten down the rocker as if you were installing it for final. Expand the pushrod until you have zero lash. Then rotate the engine to check clearances.
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Old Jun 8, 2013 | 09:46 PM
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Originally Posted by badazz81z28
Collapse the push rod checker, install it, tighten down the rocker as if you were installing it for final. Expand the pushrod until you have zero lash. Then rotate the engine to check clearances.
Correct. Then, if you are satisfied with your clearances, add your desired preload to the PR length and that's what you need for push rods.
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