2001CamaroGuy

iTrader: (6)

werd!


I'm installing Comp Rs in my new motor and baught the Comp Pro Mag 1.75 rockers just for this reason. What LG says might work but I feel better going by Comp's specs (they make it, they know what the part needs).

BoneStock

So what do we set the preload to? I've heard several answers. And then how do we set this? I don't think aftermarket roller rockers is necessary. I'm confused up to this point. Brian Tooley, chime in if you get this.

02bluess

iTrader: (18)

LS1x2

iTrader: (11)

I laugh at these threads. They come up all the time. All you have to do is shim all of the rockers the same untill you get a quiet valvetrain that is not tight. I used sheetmetal to cut my own.

verbs

Doesn't work in my situation with Yella Terra rockers, where on each cylinder the exhaust and intake rockers are joined together. Unfortunately, my intake and exhaust preload on the lifters are different. Using one size shim on everything doesn't work in my case.

2001CamaroGuy

iTrader: (6)

Verbs, are you sure you checked the pre load correctly?

to me it looks like you have a couple of things going on here...

a) your heads are fucked up (need to be remilled to make them even)
b) the intake and exhaust base circles are different diameters due to the different lift specs

Personally I think your best bet is to sell the yellas and go buy a set of rocker arms that you can adjust (I know.....shaft mount is $$$ ). Look into the Comp Pro Mags. If anything you can have your pistons notched to give you the extra valve clearance. Otherwise I don't think you will be saving yourself any money in the long run. You could scrap lifters (and possibly other parts) and get to spend a crap load more money in the end.

michael101

iTrader: (21)

I think we are starting to see that this may not be the norm. With heads being shaved, bigger springs which require taller installed height and longer valve stems, diff. base circle cams, etc. we are seeing that more information may be needed before a basic cam/lifter install than before. None of these questions/situations are that odd in the hot rod world. I think our LS1 world is somewhat spoiled because with all the help and information on these boards, we have become accustom to simply doing research, buying the part, and bolting it on. I'm thinking the "Comp R" issue is something that will become a standard research/install thing, but only after enough people go through installs with all the different head/valve combinations.

Personally, I have LS6 heads with the Crane double springs, non-stock valve stem length, and installing a FM-11. As of last night, I give up on the stock rockers. We've tried to get the preload within specs, shooting for ~ten thous. but there is just too much variation in my set up...I give up, hope to order adjustables today.

As far as hitting .004 preload goes. Mine were set like that before and noisy as hell. I think the key is "always set with the engine warm". Someone local mentioned that an aluminum engine will expand more than iron motors, makes sense. So maybe, setting ten thous. or more ends up within or close to spec. with the engine at full heat.

Z06Ron

iTrader: (2)

I'm with these guys. Would someone please outline the procedures for setting pre-load? How is it measured? On Hyd. lifters, I have always just had to get zero lash and turn so much more. I need to know how the preload is measured.

2001CamaroGuy

iTrader: (6)

with adjustable rockers, I set to zero lash and then with a dial indicator on the pushrod oiling hole in the lifter (so the tip of the dial indicator is over the pushrod), I turn the adjusting nut down till I reach 0.002". As michael101 mentioned, preload and lash should really be set with the engine hot. It does not do any good to set 0.002" cold preload only to have +/- 0.015" preload when the engine is up to temp and running. Its slow work but its doing things right.

Z06Ron

iTrader: (2)

Thanks for the reply! I knew that the dial indiacator that I bought recently would come in handy.

Crowley

I'm confused. I just ordered some 5.3L S2 heads and they recomended the Comp R lifters with my 977 springs .. am I going to have issues with this setup? This is my daily driver..

thanks,
Crowley

BB

iTrader: (7)

One ported will tell you don't need anything else. Their experience was to torque to spec and go. And they have been racing with that setup except they went with Harlan Sharps for insurance. They don't always do what the manufacturer recommends because the manufacturer will give a very safe number to protect themselves. For example, they say that the spring is only good to a certain lift, but testing on a tester shows othewise. And this porter has the expertise to know what the metal and mechanics can really do.

I on the other hand am too **** and want my preload exact to spec. Therefore I sold my YT as I had the same problems and damage verbs did and will get adjustables. Probably will go with Comp Pro Mags since I don't want cost of spacer, etc. and won't spin it to 7K every weekend - probably going to have to grind my covers even though CC says they should fit others say they don't.

Also, with the high spring pressure and high lobe lift all experts (old school and new school) recommend roller lifters to reduce side to side guide wear.

02bluess

iTrader: (18)

This is the type of info I'm looking for! I don't currently have a dial indicator; would you happen to have a mfr/part number handy?

BB

iTrader: (7)

You can get the dial indicator anywhere, autoparts store, sears, ebay, online at eastwood or harborfreight. Just search www.google.com for "dial indicator". You will need a magnetic stand too.

Pro Stock John

iTrader: (34)

Well I run the 1.7 Y/T's and I have custom length pushrods, they don't cost that much extra to get.

BB

iTrader: (7)

Would be nice to know how much expansion there is as I want to set mine up initially while the engine is on the stand and then reset latter after break in and the block is warm.

2001CamaroGuy

iTrader: (6)

I'm sure I could find you a part number. The question is how much do you want to spend? Do you have an Airgas (Rutland Tool) store where you are? If so they have a an indicator and magnetic base kit for $125.95 that would do just abut anything most people need. The model # is "2259 1020" (all 8 numbers). If you don't have one local, you can call 1-800-289-4787. I'll tell you up front that dial indicators can get exspnsive QUICK (just like any other tool).

2001CamaroGuy

iTrader: (6)

also, make sure the Range on whatever dial indicator you buy is at least 1". THere are some that will read 4-5" and others that won't go past 0.025" (but will show 0.0001").

Country Boy

iTrader: (24)

With adjustable rockers, tighten to zero lash and then 1/16 turn, maybe a hair less. That should put you damn close to Comp R specs .002-.004 isnt very much.

verbs

well, I ended up using 7.35 pushrods on the exhaust side and 7.4 pushrods on the intake side to even things out a bit. Hopefully that works out ok....and I'll be using .015 shims on the driver side head only.