Sizing pushrods in built LS
02-16-2013, 05:24 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Sizing pushrods in built LS
For the stroked LQ4 I'm building, reminder this is the cam:
And 823 L92 heads. The LS book I have says to put the valve at half lift and check if the rocker is on the middle of the stem, but that seems a bit weird. I checked for zero lash with an adjustable pushrod, and came up with 7.355".
I remember seeing someone post to go for .050" to .100" preload. If that's correct, then I should get pushrods that are 7.405" to 7.455" long. Stock are 7.400", I believe.
Tried searching, didn't find anything meaningful.
And 823 L92 heads. The LS book I have says to put the valve at half lift and check if the rocker is on the middle of the stem, but that seems a bit weird. I checked for zero lash with an adjustable pushrod, and came up with 7.355".
I remember seeing someone post to go for .050" to .100" preload. If that's correct, then I should get pushrods that are 7.405" to 7.455" long. Stock are 7.400", I believe.
Tried searching, didn't find anything meaningful.
02-18-2013, 12:00 AM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Well, my son's 5.7 came with TSP .080 wall 7.425" push rods and an unknown lumpity cam. He's put an LS6 cam in it after a refresh, and those push rods seem too long. So, he's going to put a set of LS6 push rods I had laying around, and I'm going to use his TSP push rods. Win/win, I think.
02-19-2013, 03:04 PM
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Car: Camaro
Engine: 6.2L
Transmission: T56
Re: Sizing pushrods in built LS
50-80 is where you want to be. 100 is too much for safety sake imo. IIRC 1 turn of the rocker arm bolt is 45 thou
Adjustable pr length checker is what you need
Adjustable pr length checker is what you need
02-19-2013, 07:46 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Re: Sizing pushrods in built LS
I used an adjustable push rod to establish zero plunger preload.
The 7.425" pushrods will put me at .070" plunger preload. Close enough, eh?
The 7.425" pushrods will put me at .070" plunger preload. Close enough, eh?
02-25-2013, 05:47 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Probably is. He isn't squawking about giving up his fancy aftermarket pushrods for factory pieces: but then he knows I'm using them in my LS6-clone in the Camaro and they're doing fine, plus he probably realizes I haven't said anything yet about reimbursement for his rings that I included with an order for my own stuff from Summit...
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