akw408

Let me preface this by saying that I have a TR224 cam, Comp Cam R lifters, stock rockers, and untouched 6.0L heads. I am using a test pushrod length checker to see what length pushrod I need. Does anyone know what preload the Comp Cam R lifters like? I'm planning on calling Comp Cam tomorrow, but just in case anyone here knows..

So I assume that if I torque the rocker to 22 ft-lbs and I get about 1 turn (give or take) past zero lash, then I have about the right amount of preload and the pushrod length is about right. If not, I will adjust the pushrod and try again. Does that sound about right? This other topic kind of left me confused : https://ls1tech.com/ubb/cgi-bin/ulti...c;f=1;t=005184 <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" />

Anyway, my question is does the cam need to be on the base circle for the valve/pushrod/rocker that you check? In other words, the valve should be completely closed right? Because I tried one valve and it was only .5 turns and another was like 4+ turns but the valve spring was compressing. So I'm assuming I only care about the results if that valve is closed. Is .5 turns too little preload? I adjusted the pushrod to 7.450" and now I get about 1.25 turns, is that better? <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

Is .5 turns be okay? According to the other topic, that would give me 0.039" preload. I'm thinking that may be too little. 1.25 turns would give me 0.098" preload. That may be too much. How would I do any fine adjustments to get me closer to 0.06" preload? I've heard of shimming the rockers, but not sure exactly what that is. Where would I place the shim and how thick of a shim should I use? Thanks!!

<img border="0" alt="[chug]" title="" src="graemlins/gr_chug.gif" />

jmX

1/2 a turn will be excellent for those lifters. In general, the less the better. I run about 1/8th a turn on mine and it runs great! I've had 3 different sets of lifters over the time, and 3 different heads/cam packages on 2 different motors, and the stock lifters seemed fine at 3 turns, 2 turns, half a turn, whatever, and the Comp R's seemed the same (although comp recommended running a lot less preload than stock on theirs). The point is, it seems hard to screw up. 0.5 turns will be fine IMO.

akw408

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jmX:
<strong> 1/2 a turn will be excellent for those lifters. In general, the less the better. I run about 1/8th a turn on mine and it runs great! I've had 3 different sets of lifters over the time, and 3 different heads/cam packages on 2 different motors, and the stock lifters seemed fine at 3 turns, 2 turns, half a turn, whatever, and the Comp R's seemed the same (although comp recommended running a lot less preload than stock on theirs). The point is, it seems hard to screw up. 0.5 turns will be fine IMO. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I got an email from a Comp Cam representative and he made it sound like the lifters like almost no preload, he even stated they work fine at zero lash. Sounds like you and the Comp Cam guy are saying I'll be fine with 0.5 turns or even less, so I guess I'm set. I feel better knowing that you have the same lifters and run less preload. Thanks jmx.

akw408

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by akw408:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jmX:
<strong> 1/2 a turn will be excellent for those lifters. In general, the less the better. I run about 1/8th a turn on mine and it runs great! I've had 3 different sets of lifters over the time, and 3 different heads/cam packages on 2 different motors, and the stock lifters seemed fine at 3 turns, 2 turns, half a turn, whatever, and the Comp R's seemed the same (although comp recommended running a lot less preload than stock on theirs). The point is, it seems hard to screw up. 0.5 turns will be fine IMO. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I got an email from a Comp Cam representative and he made it sound like the lifters like almost no preload, he even stated they work fine at zero lash. Sounds like you and the Comp Cam guy are saying I'll be fine with 0.5 turns or even less, so I guess I'm set. I feel better knowing that you have the same lifters and run less preload. Thanks jmx. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I asked the Comp Cam representative for more details, since he said that the lifters like very little preload and I told him I may have around 0.04" preload and this is what he said :

The .040" preload will actually damage the lifter because it has a prload built in
to it.Like I have said the recommended preload is .002"-.004" as in 2-4 thousands
of an inch.That is what makes this lifter different from others.


So now WTF am I supposed to do? I tried using the pushrod tester and made the pushrod 0.050" shorter but then the rocker doesn't even contact the pushrod.

Pro Stock John

iTrader: (34)

?

We have non-adjustable valvetrains.

To change lifter preload with stock rocker arms you really need to go up/down with pushrod length or use rocker arm shims.

I had R's and they suggest zero lash. I typically went .025 with mine. The looser you set them the noisier they will be.

I personally think the R's are hoopla and that they probably work marginally better than stock.

akw408

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Pro Stock John:
<strong> ?

We have non-adjustable valvetrains.

To change lifter preload with stock rocker arms you really need to go up/down with pushrod length or use rocker arm shims.

I had R's and they suggest zero lash. I typically went .025 with mine. The looser you set them the noisier they will be.

I personally think the R's are hoopla and that they probably work marginally better than stock. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I only got the Comp Cam Rs because they were alot cheaper than stock, after a few of my lifters got toasted. So can you fill me in on more details for the rocker shims? Where do you put them and what do you usually use to shim?

Also, how would having more preload damage the lifter? It would just cause it to bleed down quicker correct?

Pro Stock John

iTrader: (34)

Shims under the rockers, ask your favorite sponsor.

I've run the R's at .020 preload, and up to .060...

Try to keep the preload around .025 or lower...

David Plum

If shim is necc. shim the entire rocker arm stand up you will have to make shims and calculate thickness.

LS1x2

iTrader: (11)

Where can I get the shims or shim stock to make them?

Cal

iTrader: (1)

The rocker shims I've seen are just washers like you would put on a bolt. They aren't made from shim material. You might want to sort through a bunch with a mike and try and get them all close to the same thickness, though.