Pushrod length?
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Joined: Jul 2006
Posts: 10
Pushrod length?
I have built a 383 stroker that I am putting in a 89 Camaro.The block is a 71 model and it has 487x heads that have been worked and the rest is all roller.I have a Crane 4.88"-5.09" hydraulic roller cam with hydraulic roller lifters and 1.5 rocker arms.The problem is that I took the motor to the local engine shop and they said they measured it and it needed to be +100 over stock(the pushrods).But now I have it ready to run and cranked it over and it had no 
compression.So we took the valve covers off and the valves springs were just smashed way to tight and would'nt let the valves shut.Well,come to find out every were I have read says that when you switch a older motor over to a roller that the pushrods will be alot shorter.I read that factory pushrod length in a OE roller motor is 7.200 and that crane or Comp. sales retrofit 7.300 for switching to roller in a older motor.My question is if I should buy the 7.300 or purchase a pushrod length checker and check it myself before I buy anything.Also any advice from anyone with a similar project would be greatly appreciated.
compression.So we took the valve covers off and the valves springs were just smashed way to tight and would'nt let the valves shut.Well,come to find out every were I have read says that when you switch a older motor over to a roller that the pushrods will be alot shorter.I read that factory pushrod length in a OE roller motor is 7.200 and that crane or Comp. sales retrofit 7.300 for switching to roller in a older motor.My question is if I should buy the 7.300 or purchase a pushrod length checker and check it myself before I buy anything.Also any advice from anyone with a similar project would be greatly appreciated.
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Joined: Jan 2005
Posts: 220
From: orland park, IL
Re: Pushrod length?
sounds like the valves need to be adjusted. perhaps you can back off the rocker nut first and see what happens? this might allow it to close the valves. otherwise, you'll need the other length pushrods
Registered User
Joined: Nov 2005
Posts: 268
From: WI
Re: Pushrod length?
yea what he said ^ and if the rocker tip centers on the valve stem correctly, after you back off the nuts, and the rockers arent rocking right off the stems, then ta heck with it, functionality is just that
but to do it the right way, you need a checker, and i'm sure you could fab something up if you wanted to save a few bucks, but buy one and make it easy on yourself, set the checker in there and make sure your roller tip ain't rocking off the valve stem and get the set of pushrods you need.
you can get the estimations from those places, EDIT: which will likely work fine, but pushrods arent cheap, and there are angles and tolerances that affect the exact size you need like your heads possibly being shaved down, head gaskets, everything, will go and affect the exact size you need, and if you do it perfectly, you'll be rewarded with longer valvetrain life. so if you're getting new pushrods, get em perfect
P.S. nice heads by the way, I run the same ones
but to do it the right way, you need a checker, and i'm sure you could fab something up if you wanted to save a few bucks, but buy one and make it easy on yourself, set the checker in there and make sure your roller tip ain't rocking off the valve stem and get the set of pushrods you need.
you can get the estimations from those places, EDIT: which will likely work fine, but pushrods arent cheap, and there are angles and tolerances that affect the exact size you need like your heads possibly being shaved down, head gaskets, everything, will go and affect the exact size you need, and if you do it perfectly, you'll be rewarded with longer valvetrain life. so if you're getting new pushrods, get em perfect
P.S. nice heads by the way, I run the same ones
Last edited by 84firebird; Jul 7, 2006 at 09:10 PM.
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