LT4 non-adjustable rockers preload question
Thread Starter
Drifting
Joined: Aug 2006
Posts: 1,326
Likes: 18
From: Los Angeles California
LT4 non-adjustable rockers preload question
I just put my heads on and tightened the valvetrain hardware down to the required 18 ft/lb. I notice that I can freely spin all the pushrods except for the ones that are being actively pushed up by the cam. Isn't this wrong? Shouldn't the non-adjustable nuts be designed so that they tighten down to some amount of lifter preload?
I'm reading the comp cams install guide and there's actually a section on non-adjustable systems and how the rods should be checked to move .03" depending on if the nuts are tightened or loosened, but I don't think that happened with mine as I can still spin those rods freely. What gives???
Also, is there any way to visually check if that one recall has been performed on these rockers?
I'm reading the comp cams install guide and there's actually a section on non-adjustable systems and how the rods should be checked to move .03" depending on if the nuts are tightened or loosened, but I don't think that happened with mine as I can still spin those rods freely. What gives???
Also, is there any way to visually check if that one recall has been performed on these rockers?
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
I just put my heads on and tightened the valvetrain hardware down to the required 18 ft/lb. I notice that I can freely spin all the pushrods except for the ones that are being actively pushed up by the cam. Isn't this wrong? Shouldn't the non-adjustable nuts be designed so that they tighten down to some amount of lifter preload?
I'm reading the comp cams install guide and there's actually a section on non-adjustable systems and how the rods should be checked to move .03" depending on if the nuts are tightened or loosened, but I don't think that happened with mine as I can still spin those rods freely. What gives???.....
I'm reading the comp cams install guide and there's actually a section on non-adjustable systems and how the rods should be checked to move .03" depending on if the nuts are tightened or loosened, but I don't think that happened with mine as I can still spin those rods freely. What gives???.....
I tried checking with dealers, but they could not tell me if the recalls were done. I thought they had to track that info. So I would also like to know if there is any visual way to identify if it has been done.
Le Mans Master
Joined: Aug 1999
Posts: 7,339
Likes: 137
From: WilkesBarre PA
I thought there was a list of Vins that were affected by the recall, it wasn't all LT4 motors.
With the preload are your lifters pumped up? If your intake is off try priming the oil pump and getting oil to all rockers. I ran the non-adjustable ones with a hot cam for a few years with no issues.
With the preload are your lifters pumped up? If your intake is off try priming the oil pump and getting oil to all rockers. I ran the non-adjustable ones with a hot cam for a few years with no issues.
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
https://www.corvetteforum.com/forums...ml#post1969052
From that post:
The first recall (recall number 96-C-07) involved these VINs:
Regular production From: 5100052 through 5102717
Grand Sports From: 5600013 through 5600055
The second recall (recall number 96-C-07A) was extended through these VINs:
Regular production From: 5100052 thru 5111116
Grand Sports From: 5600012 thru 5600363
Thread Starter
Drifting
Joined: Aug 2006
Posts: 1,326
Likes: 18
From: Los Angeles California
The first recall (recall number 96-C-07) involved these VINs:
Regular production From: 5100052 through 5102717
Grand Sports From: 5600013 through 5600055
The second recall (recall number 96-C-07A) was extended through these VINs:
Regular production From: 5100052 thru 5111116
Grand Sports From: 5600012 thru 5600363
Regular production From: 5100052 through 5102717
Grand Sports From: 5600013 through 5600055
The second recall (recall number 96-C-07A) was extended through these VINs:
Regular production From: 5100052 thru 5111116
Grand Sports From: 5600012 thru 5600363
So my problem is that I haven't primed the oil system prior to checking hydraulic pre-load. I'm just doing those two things in the wrong order. Thanks!!
Anyone know what the upper collar on the special oil priming tool is for? The lower one is obviously for blocking the passage but I don't know the purpose of the second blue collar that slides on top.
Thread Starter
Drifting
Joined: Aug 2006
Posts: 1,326
Likes: 18
From: Los Angeles California
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Thread Starter
Drifting
Joined: Aug 2006
Posts: 1,326
Likes: 18
From: Los Angeles California
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
I just put my heads on and tightened the valvetrain hardware down to the required 18 ft/lb. I notice that I can freely spin all the pushrods except for the ones that are being actively pushed up by the cam. Isn't this wrong? Shouldn't the non-adjustable nuts be designed so that they tighten down to some amount of lifter preload?
I'm reading the comp cams install guide and there's actually a section on non-adjustable systems and how the rods should be checked to move .03" depending on if the nuts are tightened or loosened, but I don't think that happened with mine as I can still spin those rods freely. What gives???
Also, is there any way to visually check if that one recall has been performed on these rockers?
I'm reading the comp cams install guide and there's actually a section on non-adjustable systems and how the rods should be checked to move .03" depending on if the nuts are tightened or loosened, but I don't think that happened with mine as I can still spin those rods freely. What gives???
Also, is there any way to visually check if that one recall has been performed on these rockers?
Wow, thats something i didnt know bout on the LT4 - non-adj vlv train. And i came within a hair of buying and LT4 vette last fall. Whew! I could have really messed thing up. I had to look this up and thx for posting.
Well the non-adj vlv train is a product of all the tolerances of the eng combining to make a "correct" height for the rocker arm/p-rod. Now if the block has been decked or the heads have been milled or the head gasket are different compressed thickness it will affect that rocker height/p-rod distance. I dont see how u can change any of those from stock specs and end up with the same preload. But i will say that as the deck height gets shorter or the heads get milled thinner or the head gasket gets thinner the p-rod should fit tighter. Then again if the head gasket got thicker while the others stayed stock then the p-rod would become looser.
Hope this helps more than hurts.