Topic: Swapping Cams??

[Cheesemaker]

So, I am swapping out a HOT cam for a stocker for my new motor.  Both are broke in.  I have a couple questions.

1.  Do I have to keep the same rocker assembly with each specific cam?
2.  Should I use assembly lube on stuff? 

[Gnarly4X]

So, I am swapping out a HOT cam for a stocker for my new motor.  Both are broke in.  I have a couple questions.

1.  Do I have to keep the same rocker assembly with each specific cam?
2.  Should I use assembly lube on stuff? 

Hey C...

If the rocker pads still look good, I would keep the rocker assembly with the cam.

I would use assembly lube on cam lobes, rocker pads, cam journals, etc.

On my rebuild, I used the original rocker assembly on the new 261C with no problems.

On the 2nd head replacement, my local head shop examined the same rocker assembly and said it looked fine and to go ahead and use it.  I installed the original factory cam into the new head.

As you know most cam suppliers will say they will not warranty their cam if you don't install a new rocker assembly, but that is just to cover their butts.

But.. I am not an engine builder.

Gnarls.

[sirdeuce]

I've changed cams several times keeping the same rockers without issue. The theory behind using new rockers is the wear pattern. More aggressive cams hit the pads at differing angles than a stocker and vice versa. The resulting wear on the pads is mostly on the leading edge of the pad and possibly a different pad curvature than another cam's wear.
Other considerations are the transfer and retention of particles from cams with different alloys and. or hardness. The latter came from a metallurgist I had a lengthy conversation with years ago. Those scenarios would be on a microscopic level and most likely not cause any issues. Though anything IS possible.

If you want to reduce the chance of failure have the pads polished perpendicular to the cam scrape on the pads. Shop can do that on the crank polishing belt or you can do it at home with wet 600 grit  cloth/paper. Don't use a hard flat surface if you do this yourself, you don't want to disrupt the curvature of the pads.

replace any rockers with deep grooves or scratches either way.

[Cheesemaker [OP]]

Alrighty, I guess I am leaving the cam and rocker assembly together.  This way, I won't have to worry about a break in situation.  But I will put assembly lube on it all.