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Rocker arm issues

On the Comp rockers, the thru hole in the adjuster is not redundant.
That is how the pushrod is oiled.
There is no other hole in the body.
If you wanted to run solid adjuster screws, you would have to add pushrod oiling....... or you’ll start burning up pushrod tips and adjuster screws.

The Comp adjuster screws are set up to oil the pushrod in the same manner as T&D’s.

FB721B2F-00E6-42EA-B6E7-711660065A0A.jpeg
 
This is a Comp big block rocker with the adjuster set to the correct “one turn from seated” position:

View attachment 1057239 View attachment 1057240

If you look at where the OP’s adjusters are breaking, it’s where it’s broached for the hex key.
If the adjuster were properly positioned in the body, that area of the adjuster would be above where the stress is being placed.

Buy new adjusters, and the correct length pushrods so the adjusters can be positioned correctly in the body, and the problem should go away.
Thanks for the advice. What you are saying makes perfect sense. The engine is a crate motor from Blue Print Engines (493 cid). They no longer make this motor. The cam and valve train is all Comp Cams so I assume using a set like this, including push rod length, would be correct. One question though.... are your settings for the adjuster for a hydraulic lifter, such as these? I had them set to 1 turn past zero lash. Outside of this one issue, the motor has been great. Again, thanks for the advice.
 
The positioning of the adjuster screw is independent of the lifter preload.

The adjuster screw should be one turn from seated...... regardless of what type of lifter you’re using.

If you wanted one turn of preload for use with hyd lifters, you would measure for pushrod length with the adjuster screw fully seated into the rocker body.
Then, if you measured right, that position and the correct pushrods would be zero preload, then you would dial in the one turn of preload, and both the adjuster position and lifter preload would be correct.

“Most” adjustable rockers for mopars use the number of threads showing below the rocker body as the way to determine proper adjuster positioning.
For many rockers that number is 1-2 threads showing...... which is about how yours look to be set up.
For the Comp rockers...... that is not correct.
 
On the Comp rockers, the thru hole in the adjuster is not redundant.
That is how the pushrod is oiled.
There is no other hole in the body.
If you wanted to run solid adjuster screws, you would have to add pushrod oiling....... or you’ll start burning up pushrod tips and adjuster screws.

The Comp adjuster screws are set up to oil the opushrod in the same manner as T&D’s.

View attachment 1058140

well that sucks. In my best Emily Litella voice..... Never mind.
Im Pretty sure I remember this correctly, but maybe I’m mixed up. I just went and looked at some ProComp stainless rockers online, and I do NOT see an oiling hole there. My bad I guess.
 
I have some Erson roller rockers on my 302. I went to adjust them, and the head fell off. I think I went with ARP. Been 15 years. Haven't touched it since. When I looked at the broken adjuster, the grain of the metal looked like sand.
 
in my mind for this to happen either the adjuster material has to be poor, the adjuster is sloppy in the rocker threads, or the top of the rocker is not square to the threaded hole. I think its the adjuster itself. I would think if the adjuster was screwed too far out, the bottom of the adjuster would break. Along with the fact that this issue has shown up with multiple brands of rockers. And for the most part female cup style adjusters. Also in my case when the adjusters were swapped the problem went away.
Doug
 
It’s def not a problem limited to cup style adjusters.
I’ve had it happen myself with some Crane adjusters that had been in service for a few years.

I have had customers call me where the top of the adjusters have broken off with Crane, Hughes, and HS rockers.

My advice has been to buy new adjusters from someone like Manton or Smith Brothers.
 
Thanks everyone for the help. I have reached out to Manton for some help. I'm going to try and replace all the adjusters with better quality parts and see if that solves it. It seems to be the opinion of the group that this is where the problem lies. I will update this thread after I have made the changes and let you know how it went. Thanks!
 
I have some Erson roller rockers on my 302. I went to adjust them, and the head fell off. I think I went with ARP. Been 15 years. Haven't touched it since. When I looked at the broken adjuster, the grain of the metal looked like sand.
Yes, I thought the broken end of the adjuster looked very "grainy" to me also. When the last one snapped off as I was removing it, It felt brittle and just "snapped", not like a long twisting feeling. And I only had one hand on it. I'm thinking I have a bad batch of adjusters.
 
In all this talk not one has mentioned, have you talked to either the builder or Comp about this issue/problem? What do/did they have to say about it? Good Luck
 
In all this talk not one has mentioned, have you talked to either the builder or Comp about this issue/problem? What do/did they have to say about it? Good Luck
I contacted Blue Print Engines when the first 2 broke, as the engine was still under warranty. They sent me replacement rockers. They said they had never had this problem before. They were pretty helpful, however they no longer produce this engine. I contacted Comp Cams and they were not much help..... unless I wanted to buy a new set of rockers.
 
Here are the instructions from T&D on where the adjuster screws should be set:

A810E776-1465-4128-86F3-DCCBB0B1F46B.png
 
I contacted Comp Cams and they were not much help..... unless I wanted to buy a new set of rockers.

That's the typical big biz bullshit. Good Luck
 
New adjusters are on the way from Manton. Nice people to deal with. The cost of those things are steep, so I'm hoping for the best. I'm going to replace all 16. I'll post an update when I get it done. Thanks everyone for the advice.
 
Well I finally got it back together. Comp Cams sent me mis-packaged rockers twice. Right side rocker package and part number with a left side rocker inside! Then the right side were backordered. I used the Manton adjusters, they were great to deal with. So far, no problems.
 
Thanks for following up:thumbsup:
 
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