5.0 HO Roller lifter pre-load

Topic: 5.0 HO Roller lifter pre-load (Read 4303 times) previous topic - next topic

5.0 HO Roller lifter pre-load

November 08, 2011, 08:17:26 PM

Do you guys know how to figure out the correct length of push rods? I believe my pushrods are too short and causing some valvetrain noise.

Here is a picture of my rocker setup (1993 Cobra Crane rockers)...

I have the stock HO cam with stock roller lifters and 1993 GT40 heads and valves, but with TFS springs. I used the pushrods that cam from the same engine the fully assembled heads came from. It only had idle time.

I just ordered a Comp Cams adjustable pushrod to measure the length between the lifter and rocker arm.

But how do I work the adjustable pushrod? Zero lash is when I can't spin the pushrod? How much longer should the pushrod be from zero lash to pre-load the lifter?

5.0 HO Roller lifter pre-load

Reply #1 – November 08, 2011, 09:43:53 PM

.....this may help with the pattern you are trying to attain by varying the push rod length.

http://sbftech.com/index.php/topic,317.0.html

5.0 HO Roller lifter pre-load

Reply #2 – November 08, 2011, 09:54:12 PM

.....or this may be closer to your set up.

http://sbftech.com/index.php/topic,28993.0.html

5.0 HO Roller lifter pre-load

Reply #3 – November 08, 2011, 10:02:34 PM

^ gotta love sbf tech :)

5.0 HO Roller lifter pre-load

Reply #4 – November 08, 2011, 10:25:08 PM

Hey Shredder, I hope that the noise that you hear is not a result of the rocker rubbing on the VC as indicated by the scuff marks on the part # of the rocker in the pic.

5.0 HO Roller lifter pre-load

Reply #5 – November 09, 2011, 10:23:58 AM

Quickshift, the rocker rub mark is from the filler tube baffle.

All other rockers are FINE with no clearance problems.

Thanks for the links to sbftech. It appears that zero lash is no play between pushrod and rocker. Then about 0.020 - 0.060" pre-load. I'll get that measured up.

5.0 HO Roller lifter pre-load

Reply #6 – November 09, 2011, 04:34:31 PM

Quote from: QUICKSHIFT;372373

Hey Shredder, I hope that the noise that you hear is not a result of the rocker rubbing on the VC as indicated by the scuff marks on the part # of the rocker in the pic.

Ya'll beat me to it.

5.0 HO Roller lifter pre-load

Reply #7 – November 09, 2011, 05:31:38 PM

.. i didn't even realize.. lmao