Author Topic: Rocker arm problem (Read 390 times)

Dne' · « **on:** November, 20, 2009, 07:14:18 PM »

I finally got my little 289 running the other day, but just briefly as I didn't have exhaust installed yet, and it did have a popping back through the carb, but didn't give it much thought at that time. So, I had the exhaust installed and able to take note to the popping back much better. I let Herb(the engine builder) listen over the phone, and he said, "sounds like a broken rocker arm". I say, "you can tell me that by listening over the phone!" lol So I took the left valve cover off after finding out where it came from by pulling spark plug wires at the cap(Herb told me how to find where it was) it was number 8 cylinder. After removing the valve cover, there it was, a broken rocker arm! split at the point where the push rod comes up. Herb came over with a new RA, and we worked on it, but found it had a bent pushrod, but he didn't bring one, so I bought a pr the next day, installed it, started the motor and the rocker during adjustment worked its way off the valve and bent that pushrod! argh! Called Herb~ he's so calm! Sounds like I'm going to have to pull that head off! oh rats!

So he asked when he could come over, but I say I can pull the head, and you can come help me put it all back together~ which I went ahead and did. It wasn't that bad to get it dissassembled, but the head is heavier than I cared to lift, so I used my engine crane to lift the head off(brains over brawn!) I could see on the spot where the rocker rides on the valve and it was kind of "worn" looking and that's the way the rocker went off. I don't know what happened, but I'm going back with new roller rocker arms and new pushrods. Herb seems to think that the old rocker arms, or that particular rocker arm was just old and its time was up! lol

Long story short, and lesson learned, Things happens(to put it nicely)! Herb has followed through and I'm so happy to have him as MY engine builder and friend!

RustyRed · « **Reply #1 on:** November, 20, 2009, 07:57:31 PM »

Sorry to hear about the trouble but Herb is pretty good to fix issues when / if they come up.

I called him when we figured out we had a harmonic balancer issue with my motor and he came right over, he looked at it, made a call, left for a while and then came back with the correct balancer that would work with a 302 pulley. Apparently, his guy sold him the wrong balancer and we didn't start putting the "front" of the motor on until later. I am sure it was a 302 balancer that was on it, just one that wouldn't work with a '66 style pulley.

Getting a new motor in and running can be a challenge with lots of "issues" that come up as I learned recently. Heck, I still haven't had a chance to hook a vacuum gauge up to mine to get the carb adjusted, LOL!

Hang in there and you'll get it.

cmayna · « **Reply #2 on:** November, 21, 2009, 07:21:50 AM »

Dne',
Are these stock rocker arms you're running?

Dne' · « **Reply #3 on:** November, 22, 2009, 08:32:12 AM »

After Herb told me about removing the head, I had just gotten cleaned up! put my coveralls back on and went to work removing the head! lol I think I had it off within an hour! I don't know why we didn't see the end of the valve, guess we we're looking for anything else other than a defective rocker arm. Anyway, the head is in Herbs hands now, today I'm going to go out and prepare the surfaces for when Herb comes back over~ hopefully we should have it back up and running by next weekend. and maybe by then my longer tie rods will be in from flaming river!
dne'

This photo was taken after the rockerarm shifted and pushrod bent, and then the verdict came that the head has to be removed.

Midlife · « **Reply #4 on:** November, 22, 2009, 09:27:22 AM »

So let me understand this...first you found a broken rocker arm, probably due to a bent push rod. You replaced both the rocker arm and the push rod, and now the rocker arm comes off again and the new push rod is bent? This does not sound good to me at all! Something is drastically wrong if push rods keep getting bent.

Dne' · « **Reply #5 on:** November, 22, 2009, 11:11:48 AM »

Yes, Herb suspected something much more than just a rocker arm prob, so that's why he instructed me to remove the head(he was going to do it, but I went ahead and took it off to facilitate things). If you look closely at the end of that valve, maybe they didn't machine it correctly, or the rocker arm took out the end of the valve? I don't know~ we'll be going back with roller rockers if that will help~!

Quote from: Midlife on November, 22, 2009, 09:27:22 AM

So let me understand this...first you found a broken rocker arm, probably due to a bent push rod. You replaced both the rocker arm and the push rod, and now the rocker arm comes off again and the new push rod is bent? This does not sound good to me at all! Something is drastically wrong if push rods keep getting bent.

johnpro · « **Reply #6 on:** November, 27, 2009, 02:57:26 PM »

There is no way the rocker should come off the valve or break.

If I had to guess, I'd say the first rocker broke because of coil bind and the second slipped off because it wasn't a rail rocker.

In other words, I'm guessing you have the wrong valve springs for your cam, and put the wrong rocker arm after the first broke. Both of these should have been caught by even the worst of engine builders.

I don't think I'd be taking it back to the same guy.