screw in rocker studs
Thread Starter
Drifting
Joined: Nov 2006
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From: Ontario
screw in rocker studs
planning on using LT4 1.6RRs in my L98, first off I assume I need to switch the studs right? the 1986E doesn't have screw in studs right? how much would it cost to convert to screw in studs?
Thread Starter
Drifting
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From: Ontario
Le Mans Master
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From: One day you're a Comet...the next day you're dust... Arkansas
Thread Starter
Drifting
Joined: Nov 2006
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From: Ontario
not sure what the L98 is but I'd probably switch to screw-in anyways, I hear it's much better. just trying to get a feel for what I need to do, looks like comp cams sells a tool to remove the boss then I can tap the hole... sound right?
Team Owner
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Burning Brakes
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From: Spring Grove Illinois
Thread Starter
Drifting
Joined: Nov 2006
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From: Ontario
yeah a machine shop seems best idea so far if I have to grind the boss down, however I read on another site you only need to grind the boss if using guides, I won't be using guides so could I not just tap the hole? (using a guide to make sure it's straight of course...
http://www.maxchevy.com/tech/2007/ii_12-stud-1.html
http://www.maxchevy.com/tech/2007/ii_12-stud-1.html
Burning Brakes
Joined: Sep 2006
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From: Spring Grove Illinois
Are these Self Aligning RR ???..If Not pretty sure you need Push Rod guide plates..If they are Yes you can tap the hole with the desired tap using a guide block..Keep it straight and use kerosene as a lube on the tap.. Go slow (a few turns in and then 1/2 turn out) it will load up quickly..Cast is like dust..
Thread Starter
Drifting
Joined: Nov 2006
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From: Ontario
just after some quick reading I believe they are self-aligning. And it appears they are metric not SAE at the top need to find out what they are at the bottom.
I'll have to find out the measurements of the bottom of the stud to see if I they are 7/16, if not I'll have to go buy some.
Also thanks for the tip on tapping
The LT4 roller rockers are self-aligning (i.e. they have guides to keep the rocker arm tip on the valve) but they are non-adjustable (i.e. torque 'em and go versus setting 0 lash + ¼ or ½ turn depending on preference). In addition, the LT4 rocker arm studs are 10mm as opposed to the more common 3/8" or 7/16"
Also thanks for the tip on tapping
Burning Brakes
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From: Spring Grove Illinois
Thread Starter
Drifting
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From: Ontario
okay well more reading the top of the stud should be 7/16"
the rockers I got were from after the recall so they should not be early. Also seems the bottom is 7/16 as well for sure so even if the top isn't 7/16 I can still use my studs by tapping 7/16" holes for the studs. Sound about right?
Both the LT1 and the LT4 Heads accomodate 7/16" studs but the LT4 has larger 7/16 rocker studs. There are some reports of early LT4's with 10mm top threads. The LT1 studs are 3/8" on top and 7/16" bottom. GM part numbers are #3921912 for 7/16" LT4 and #1255216 for 3/8" LT1.
Burning Brakes
Joined: Sep 2006
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From: Spring Grove Illinois
okay well more reading the top of the stud should be 7/16"
the rockers I got were from after the recall so they should not be early. Also seems the bottom is 7/16 as well for sure so even if the top isn't 7/16 I can still use my studs by tapping 7/16" holes for the studs. Sound about right?
the rockers I got were from after the recall so they should not be early. Also seems the bottom is 7/16 as well for sure so even if the top isn't 7/16 I can still use my studs by tapping 7/16" holes for the studs. Sound about right?
Thread Starter
Drifting
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From: Ontario
If your not sure of the stud size you have run a nut down on the threads...If they are 7/16 (bottom) go for it..Check the top the same way if a 3/8 nut won't thread on it's probably metric..Either way rocker studs are available anywhere...Lets us know how it worked..PICS PICS PICS..
Melting Slicks
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From: Oakbank Manitoba
You can't use original equipment LT4 rockers as the nuts don't have set screws in the top to lock them down. The Lt4 rockers are non adjustable....there was no setting preloads with them.
Thread Starter
Drifting
Joined: Nov 2006
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From: Ontario
Thanks STL for the clarification
