152 rockers

Mastiff

Mastiff

Member
What options do I have regarding worn rocker pads - the ones that contact the valves? I have the 9 bolt rocker assembly. I don't know if I have excessive wear, but should I consider having a machine shop surface them somehow, or can I press out and replace the whole pad and stem?
 
Okay. I have an e-mail in to him asking about that. He sent me a link to the boat style, but I have the other kind. If someone is rebuilding them, the pads must be obtainable someplace? Or maybe they make one good assembly out of several old ones?

I really don't know how anal to be about this stuff. The pads are pretty good but not perfect, same with the shaft. Same with the lifters for that matter. I'm getting different advice from everyone I ask on all these things.
 
The rockers are re bushed, shafts are reground and plated up to proper diameter, the balls are replaced in many cases and, the valve wear pads are resurfaced parallel to the rocker shaft cl. Not just a spit shine deal.

A boat system is fine and May be cheaper that rebuilding idk.
 
I got the price from Jeff on a rebuilt assembly and it's not cheap but reasonable and worth it for the peace of mind. I'll replace the lifters and rockers. Is there anything I should know about pushrods at this point? If they look good and straight am I okay?
 
The pushrods will be fine so long as the ball and cup ends are not galled. When you assemble the rocker assy try to make sure you have lifter preload. .025 min .075 max.

Not easy to measure but maybe you can get one of Jeff to send you a loaner adjustable pushrod to borrow.

You only need to make sure the lifter is on the heal of the lobe for the location you are checking. Remove the existing push rod and install the adjustable rod and replace the rocker assy. The rod is then extended until it takes up the distance between the lifter socket and rocker arm socket. Then the rod is removed making sure you don't move the setting and measure it's oal and compare it to your run rod length. The difference is the preload. I would like to see between .025 and .075".
 
This would be done with the cam in such a position that the valves are all closed? If the preload isn't as desired, do you pump up the lifter to get it right? Thanks.
 
Do one valve at a time. So that the valve is in the fully closed position.

Only way to alter preload is to use longer/shorter push rod.

To be totally honest with you, at your current engine knowledge level just assemble the engine using the new parts from Jeff and see how it is. Most of the time they are fine so long as the head/block/valve stems have not been ground a long way. If all valve's quiet down in 5 -10 minutes of running all is fine. Upon start up you will experience a lot of ticking/tapping until all of the air in the lifters is exchanged for oil. It will go away.
 
You beat me to it. I went out and researched and was starting to understand. Just for my understanding though, how do you do this adjustment when the lifters could be all over the place? I mean, recent experience tells me that they tend to pump up and stay pretty solid for a long time. The measurement with new, dry lifters would be night and day compared to what you'd get after running then engine. Right?

Thinking it out, maybe I do understand. Even on a dry lifter, the spring will push it out to maximum length, so the zero lash baseline is relative to that. You are saying that you'd like the lifter to be compressed a minimum of 0.025" from it's maximum length. The 0.025-0.075" would be the range of the lifter to absorb slop and variation.

Is that the right way to think about it?

Anyway, yeah, I'll verify the pushrods look clean and straight and just see how it goes. If it makes noise I can work on it in the vehicle. 99% of people must be running factory lifters in these things...
 
Lifter preload has nothing to do with oil being in the lifter is has to do with when the valve is closed and the lifter is on the heal of the lobe, how far the plunger is set down in to the lifter by the valve train geometry. That way the oil and lifter valving can maintain 0 lash.

You should coat the cam lobes and lifter faces with a cam assembly lube. Usually heavy black moly fortified grease specifically designed to lubricate your cam and lifters during the first turns of your engine until oil gets there.
 
Robert kenney said:
lifter preload has nothing to do with oil being in the lifter is has to do with when the valve is closed and the lifter is on the heal of the lobe, how far the plunger is set down in to the lifter by the valve train geometry. That way the oil and lifter valving can maintain 0 lash.
Click to expand...

You May not be able to tell, but that's what I was trying to say. :icon_rolleyes:

you should coat the cam lobes and lifter faces with a cam assembly lube. Usually heavy black moly fortified grease specifically designed to lubricate your cam and lifters during the first turns of your engine until oil gets there.
Click to expand...

I've been using lubriplate for everything so far. It's white. The engine builder just recently gave me a tube of some other stuff he likes, it's darker and I'll use that on the lifters now that I have it.

Thanks for the help.
 
I have very limited reading comprehension so I probably missed it. :out: :arf:


for future reference, oil on bearings (I use 90wt gear oil for bearing assembly lube) and the dark stuff on cam and lifters.

Pre-oil by turning the oil pump
 
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