1990 L98 PR Guide Plates problem
Thread Starter
4th Gear
Joined: May 2007
Posts: 4
Likes: 0
1990 L98 PR Guide Plates problem
I have problem. My L98 came to me with guide plates, but the rockers arms do not line up with the valves. It looks like the grooves in the guide plates ate too close together for the valves. Every rocker arm is at an angle. Are L98's supposed to have self aligning rocker arms?
Now I have valves with slightly shorter stems, and I don't know if they will work with stock self-aligning rockers. Has anyone else encountered this?
Now I have valves with slightly shorter stems, and I don't know if they will work with stock self-aligning rockers. Has anyone else encountered this?
Melting Slicks
Joined: May 2000
Posts: 2,148
Likes: 1
From: Chandler AZ
Yes, from the factory they are self aligning using the valve stem. There is however a "guide plate looking" thing in there which held the pushrods in place during assembly.
Bottom line is you can't fix the rocker at both ends- and it's really better to align using the pushrod rather than the valve stem. Sounds like a good time for some roller tipped rockers!
P.S. if your valve stems are shorter, check the geometry- you might need to adjust pushrod length.
Bottom line is you can't fix the rocker at both ends- and it's really better to align using the pushrod rather than the valve stem. Sounds like a good time for some roller tipped rockers!
P.S. if your valve stems are shorter, check the geometry- you might need to adjust pushrod length.
Thread Starter
4th Gear
Joined: May 2007
Posts: 4
Likes: 0
The problem is, when I bought the car it had a lot of rocker arm noise. When I inspected, I found the pushrods were wearing through the guideplates. I think they might have been the "guide plate looking" assembly aides. Anyway, one side had roller tip rockers, the other had regular non-self aligning rockers. The side with regular rockers had some severe valve stem damage because of the severe angle of the rockers. One rocker arm has completely slid off the stem of the valve. The rockers and valves on that side were completely destroyed. I bought new Comp Cams guide plates(4808), but it still seems something is a little off. The rocker arms are still at a slight angle.
I know that I need hardened pushrods, how can I tell if mine are hardened? The original guideplates were worn severely, but the pushrods show no damage.
I know that I need hardened pushrods, how can I tell if mine are hardened? The original guideplates were worn severely, but the pushrods show no damage.
