[Dfosticz]

Can anyone help me with the proper amount of lifter preload? Ive found anywhere from .060-.100. Just looking for the proper spec.

 

[BO185]

Can anyone help me with the proper amount of lifter preload? Ive found anywhere from .060-.100. Just looking for the proper spec.

Are you using stock rockers or adjustable units and getting your pushrod length for a different cam? Ideally I would run .080-.090.

 

[Dfosticz]

Stock rockers with a tick performance stage 1 turbo cam

 

[hotrodg726]

Ideally 1/2 of the plunger travel is what you want. Should be around.075-.080

 

[BO185]

Stock rockers with a tick performance stage 1 turbo cam

The rockers are self adjusting install and torque preload is set, but you will need to verify push rod length as the cam isn't stock to verify preload.

Most times you can call the trick and they can give you a PR length if you don't have a checker at least they use to. Just makes sure to tell them you have the LS7 1.8 rockers. Or if you have a PS checker install it, install rockers, set load. Remove and measure that is your PR length you need.

 

[Dfosticz]

I have a 5.3 with ls7 lifters. I have a pushrod length checker. I need to know the preload to add after i check length. Stock 1.7 rocker arms from 5.3

 

[hotrodg726]

read post 4 .

 

[BO185]

I have a 5.3 with ls7 lifters. I have a pushrod length checker. I need to know the preload to add after i check length. Stock 1.7 rocker arms from 5.3

Ahh ok yeah the LS7/LS3 lifters are same. Install checker torque rocker arms to 22fl/ft. adjust PR checker to set preload .80-90, remove rod checker, and measure it. Thats the push rod length you need. When you install them and torque rocker arms it will be set to what you spec'ed

 

[Dfosticz]

So i checked and with the cam on base circle i installed the rod checker and get zero lash at 7.270 length. So i added .08 to get my 7.350 pushrod length. I have 799 heads on a 99 5.3 with a mls gm gasket, tick turbo cam and ls7 lifters. I thought they would be stock length. Does this seem weird?

 

[BO185]

Does this seem weird?

No not really. One reason to check it. The stock truck push rods are 7.4'' and the cam has a smaller base I assume, than the stock truck cam so no surprise really.

 

[Dfosticz]

Well its not supposed to have a smaller base circle. Are the mls gaskets thinner than the graphite gaskets?

 

[BO185]

Well its not supposed to have a smaller base circle. Are the mls gaskets thinner than the graphite gaskets?

Smaller than what the truck cam? There are alot of factors again one reason to measure and know what you need. Did you measure with an old head gasket or just calculate it? The MLS are little thicker than graphite.

 

[Dfosticz]

I measured with the new heads and mls gaskets installed with heads torqued down. Just worried about being off on my measurement.

I put the length checker in and turned the motor over til the checker was at the bottom of the travel and wasnt moving up or down when i turned the motor over. I then torqued down the rocker and checked for lash. At 7.265 there was a little bit. At 7.270 the rocker was snug. So plus.08 is 7.350. Was this correct way to check? If im a little short, worst case the motor will be noisy at start up and i can go longer?

 

[hotrodg726]

I measured with the new heads and mls gaskets installed with heads torqued down. Just worried about being off on my measurement.

I put the length checker in and turned the motor over til the checker was at the bottom of the travel and wasnt moving up or down when i turned the motor over. I then torqued down the rocker and checked for lash. At 7.265 there was a little bit. At 7.270 the rocker was snug. So plus.08 is 7.350. Was this correct way to check? If im a little short, worst case the motor will be noisy at start up and i can go longer?

that is fine and 7.350 is a common aftermarket pushrod size for ls engines .

 

[BO185]

I wouldn't go longer. Worst case if to short you don't get max lift. If you measured 7.35 run them.

 

[Dfosticz]

So i got the car fired up and the valve train knocked and clicked for a few min then got quieter but it still sounds like a sewing machine. Im wondering if i shouldnt get the stock 7.400 pushrods and run them? Would it hurt to put the stock ones in to do a test? I have a .610 lift cam amd dual valve springs.

 

[hotrodg726]

So i got the car fired up and the valve train knocked and clicked for a few min then got quieter but it still sounds like a sewing machine. Im wondering if i shouldnt get the stock 7.400 pushrods and run them? Would it hurt to put the stock ones in to do a test? I have a .610 lift cam amd dual valve springs.

most hotter cams with modern grinds have some valve-train noise due to the steep ramp angle on the roller cams. I would not go longer on the pushrods. just learn to live with the noise. my 4.8l with .604 lift is the same way. sounds like a singer sewing machine. excessive spring pressure exacerbates the issue too.

 

[Dfosticz]

I measured for length the first time and came up with 7.400. I then rechecked and came up with 7.350. Which is what is in it. It is ticking/knocking pretty good. So I just remeasured and came up 7.400. I ordered a set of 7.400 so il see what happens. I may use a dial indicator tomorrow to see the preload with the old 7.350.

 

[hotrodg726]

just be sure your not bottoming out the plunger in the lifter. if you do it will start to hang the valve open.

 

[Dfosticz]

I dont believe I will. I put stock length 7.400 in and im getting about .090 to .095 preload. Which means with the 7.350 im only at .040 to .045. Probably why its a bit loud