Nads06111

iTrader: (1)

I installed the Hotcam kit. With the rockers I spun the pushrod until I felt resistance, then turned the nut a 1/4th turn.

The car runs, but I don’t know if I should re-adjust.

1redta

how did you do this, running or not? what type of roller rockers?

I like to set the rockers with the motor running.
1. loosen them till they "clack"
2. tighten till they stop "clacking"
3. turn less than 1/4"
4. tighten allen head ,hold the nut from spinning,
5. turn a smidge more to seat everything
6. WOT give her hell

ryanisfast

I would go a little more than 1/4. I went 3/4. Some people say that's ideal though, but also make sure you tightened them when the pushrod was sitting on the base of the lobe. If you're using after market rr's with a locking allen in the center make sure to tighten it really good also!!

You should have had to turn the crank to do it right.

btw, I'm obvoiusly talking about doing it with the engine off.

MattSapp95_T/A

iTrader: (35)

As instructed by Lloyd Elliot

Tighten until the push rod has no up and down play then 1/8 - 1/4 turn preload...

Nads06111

iTrader: (1)

they were the RR that came with the Hotcam kit.

so 1/4 to 3/4 turn is acceptable?

chevymec

iTrader: (19)

I've always done 1/4 turn after zero lash.

great421

iTrader: (1)

Yep - on stock lifters, 4 1/2 flats or 3/4 of a turn, per an ASE-certified GM master mechanic.

RamAir95TA

iTrader: (2)

I've always used 1/4 TPZL with OEM/replacement LS7 lifters.

JAKEJR

Most guys use too little preload based on something someone said at one time or another, but I'm not going to join that fight yet again.

Here's what you need to know: The MOST IMPORTANT PART of setting lifter preload is to make ABSOLUTELY SURE the lifter is riding on the camshaft's base circle/heel. If that's wrong, everything else that follows will be wrong.

Jake

leadfoot4

iTrader: (1)

This is why I prefer to get them as close as possible, then fire up the engine, let it FULLY warm up, then re-set them with the engine running. As "great421" said, GM shop manual calls for 3/4 turn past "zero lash", but that's with GM lifters.

I think what "JAKE JR" is getting at, is the Comp Cams 875R lifter setting, which is 1/8 turn preload MAX, per conversations I personally had with two different Comp Cams tech reps. HOWEVER, trying to accurately set that small amount of preload is a "whole 'nother story". Believe me, as I had those lifters in my car for a while, and it took 3-4 times before I got it where they weren't 'clattering', but not too tight....

white97t/a

iTrader: (2)

Once done, should you be able to spin the pushrod with your fingers?

SS RRR

iTrader: (2)

Agreed. I don't get the whole adjusting hyd. rockers so lightly. I ran 1/2 turn past zero lash which ensured if I ever had valve float issues I would destroy the lifters as what has been seen over and over again with the Comp R's.
And yes, OP. If you did as such knowingly doing so on the base circle of each lobe then you have nothing to worry about. If you don't know, then you should adjust them again. Shoebox has several methods on this: www.shbox.com
IMO wiggling the pushrod up and down will give you more consistent results of finding lash over twisting.

Nads06111

iTrader: (1)

thanks.
what is the best way to ensure that i am at the bottom of the lobe?

SS RRR

iTrader: (2)

quik95lt1

iTrader: (7)

heres the easiest way to do this........when the intake valve begins to return from full lift adjust your exhaust valve......when the exhaust valve begins to open adjust your intake valve

AChotrod

iTrader: (17)

follow steps 7-8 never had an issue this way
http://www.compcams.com/Instructions/Files/151.pdf

Nads06111

iTrader: (1)

and thats better than doing it when the cylinder is at TDC?

AChotrod

iTrader: (17)

thats how comp says to do it and thats how I do it never had an issue. Dont matter TDC as long as the lifter is on the base circle. It will be on the BC this method

Wicked94Z

iTrader: (26)

FWIW... 5 years now on Comp 875s with as much as 1/8 turn preload hot, and currently with ~1/16 turn cold which is probably 0 when the motor gets up to operating temp. Never had any problems, except they are pretty noisy.

Nads06111

iTrader: (1)

well if it's at TDC wouldn't both lifters be on the base circle of the cam lobe?