Author Topic: Red Neck wrenching lifter preload  (Read 2602 times)

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Offline larrym

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Red Neck wrenching lifter preload
« on: February 12 2015, 02:08:07 PM »
So I had some noise in my new motor that is covered in another thread.....
Before I pulled it I wanted to check my lifter preload, I have an adjustable push rod set it to zero lash brought it to my machinist with the pushrod I was using he measured and said it looks like .045 to me that's pretty much perfect from my understanding.


I wanted to double check a few more I had read on the other board were someone was trying to figure out their preload without an adjustable pushrod, figured I would try it.


Here is what I did install 1 pushrod start all the bolts holding the rocker shaft get them finger tight with a little movement on the pushrod, slowly tighten the nut closest to the pushrod with your fingers until you get zerolash next tighten the nut fully and note how many turns, in my case 3/4 of a turn.
Now for the math the bolt is 18 threads per inch so 1 full turn 1/18=.0555555 next 3/4 of that so .055555*.75= .04166


Its not exact but it will give an idea of where you are at I was lucky to have the adjustable pushrod but I did not have the the tools to measure it.
86 white T type with t tops and blackout trim. 60lb injectors Gen 2 with Extender Chip TR6 ignition 212/206 roller cam Turbonetics BB CPT 61 CAS V4 Intercooler Cobbled together Alky Injection 4 inch MAF pipe with integral sensor
2800 stall lots of fun with a little 6 banger!
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Offline Just a Six?

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Re: Red Neck wrenching lifter preload
« Reply #1 on: February 12 2015, 02:48:22 PM »
Sounds close enuf to me since the pre load can vary an easy 20+ thousand from build to build. Wasn't stock close to 45ish yet many aim for 30ish depending on the parts used.     
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Offline Steve Wood

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Red Neck wrenching lifter preload
« Reply #2 on: February 12 2015, 03:21:40 PM »
0.025 is what I would aim for on built engine for maximum rpm without pump up but some of the stock factory engines were probably over 0.050.

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Offline Steve Wood

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Red Neck wrenching lifter preload
« Reply #3 on: February 12 2015, 03:23:25 PM »

duplicate
« Last Edit: February 12 2015, 03:44:03 PM by Steve Wood »
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Offline earlbrown

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Re: Red Neck wrenching lifter preload
« Reply #4 on: February 13 2015, 03:55:09 AM »
'87 GN - 4.2L SFI Turbocharged innercooled V6 - Chrome valve covers - supra pump - 14" K&N - 52mm throttlebody - rocker shaft supports -  1/2 intake spacer - TB coolant bypass - 3" ATR exhaust tip - Alum intake pipe - NOS timing cover - chip - relocated charcoal canister - CR42's - stock

Offline Steve Wood

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Re: Red Neck wrenching lifter preload
« Reply #5 on: February 13 2015, 09:58:18 AM »
I just wanta be in one of your movies
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Offline larrym

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Re: Red Neck wrenching lifter preload
« Reply #6 on: February 13 2015, 03:38:30 PM »
hmmm The spec I found for the Morels I use was no less than .030 no more than .050 but the interweb has lead me astray before......

86 white T type with t tops and blackout trim. 60lb injectors Gen 2 with Extender Chip TR6 ignition 212/206 roller cam Turbonetics BB CPT 61 CAS V4 Intercooler Cobbled together Alky Injection 4 inch MAF pipe with integral sensor
2800 stall lots of fun with a little 6 banger!
Best ET 11.36

Offline Steve Wood

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Re: Red Neck wrenching lifter preload
« Reply #7 on: February 13 2015, 05:25:16 PM »
I was thinking stock rockers...soun ds like you are in the range for that specific lifter
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Offline ULYCYC

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Re: Red Neck wrenching lifter preload
« Reply #8 on: February 15 2015, 10:35:03 AM »
hmmm The spec I found for the Morels I use was no less than .030 no more than .050 but the interweb has lead me astray before......



That spec is to cover all applications. For iron block and iron heads keep it close to .030.   If you beat the piss out of it .025-.030 would work best.
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