Valvetrain geometry setup problems and questions

RANT- I HATE PEDESTAL MOUNT HEADS!!!

OK, so I'm trying to get my engine put together and I worked on setting up the valvetrain tonight. Its been almost 5yrs since I last did this and I forgot how much I hated it. I have a problem, I'm using a pushrod length checker to determine what length I need for proper pre-load. I think I have the length I need but I have two problems:

1. I need a shim under the intake pedestal to get obtain the proper preload. Without the shim I'm getting a hair over a 1/2 turn preload on the exhaust lifter. To get the same on the intake I needed the thinnest shim from my pack with the same length pushrod. I had to run this same setup on my old combo with my AFR 165's. The preload is the same on the intake and exhaust, but the pushrods show different wear patterns. Does this wear pattern tell anyone anything? My gut tells me that it shouldn't be different, but the preload is similar. I assume its a geometry issue, but I'm not sure. Here's a pic:

The pushrod on the right is the one from the exhaust, the pushrod on the left is the intake that has the shimmed pedestal. You can see that the entire end of the exhaust pushrod is shiny (on the right) and only a little part of the intake(on the left) is.






2. Second problem is that with these 185's, with the pushrod length adjusted so that I get 1/2 turn of preload the roller rocker roller tip is sitting on the back side of the valve tip. The only way I can think to get the proper geometry is to put thicker shims under the pedestal. I haven't had a chance to rotate the engine to see the total valve tip travel of the rocker, but I think its too far towards the lifter valley. What do you think? If I need to move the tip more towards the center of the valve tip how do i accomplish this with pedestal mount heads? I'm thinking I need to run shims under the pedestals and run longer pushrods, is that correct? The roller tip is not running off of the valve tip JFYI.

Here's some pics:

Rob, they are the same exact pushrod, but it does sort of look like they are different in the pics. The entire end of the one on the right is worn and shiny, the one on the left only has a thin shiny ring. Thanks though!

Here's a crude pic that shows the pushrod wear:

EagleAutosports said:

Looks like you definately need longer rods. That roller tip needs to be in the middle of the valve before, during, and after you rotate the engine over. Mark the top with a marker and look at the wear pattern.

Click to expand...

Thanks for the reply. That's what I thought I'd have to do. I was all excited when I got the proper preload and then I looked at the roller tip. I can't find my old shim pack so I guess I'll have to buy a new one to get the rocker up higher and then go back to the drawing board on pushrod length.


Does the wear pattern tell anyone anything? There has to be a reason why it looks like it does, but I don't what that is. When installed on my old combo, the rocker tip visually looked to be in the same location on both the exhaust and intake valve tip and preload was virtually the same.