The Stovebolt Site Forums The Shop Area Engine Shop Broke another push rod

I had my 62-235 rebuilt several years ago , new lifters, cam, pistons (bored .030" over), oil pump, crank was OK. after 3 or 4 years the hyd. lifters started bleeding down when it sat for a while. I tried changing one at a time trying to identify which one or ones were sticking down. Finally I changed all of them with Mellon lifters. I guess my engine builder used cheap Chinese lifters. So now from the warm up heavy ticking in the past I guess the top of the push rods got weak. This is the second one that broke the same way, one intake and this time a exhaust. The bad part is my truck is a COE. I've spent a lot of time in the passenger side door way!

What feedback did you get from your engine rebuilder about this problem?
Usually a good engine rebuilder, with experience on the old Stovebolt engines, will have a recommendation on which parts to use.
That is, parts that historically give less problems.

He's a X coworker I told him I was having lifter issues, that was the last time I seen him. But like I said it was fine for 3 or 4 years so I didn't get into it with him after it had been that long. I guess I should have touched bases with you guys first.

I had a '56 Cadillac engine rebuilt 15 or so years ago. Builder refused to use the Kanter parts supplied in a kit. Rocker arms, pushrods were sent back and originals reused. New stuff is CRAP!

Are you using the original push rods or did you replace them with some aftermarket tube push rods? Believe it or not the aftermarket tube push rods are stronger then the stock solid push rods. If you are running the original solid rods, consider replacing them with some aftermarket sealed power, trw or other new tube type push rods.

Learning by bad experience is not the cup I like to drink from. I feel your pain. Read this:
https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/1387191/2.html

Other than lifters, hard oil sludge in the valve guides or wrong valve guide material, maybe.

I agree with Mike. I replaced mine on a 235 (solid lifters) for bending. Worked well.
If the lifter has collapsed and is sticking hard, it may allow the push rod to fall out of the rocker arm cup (engine running).

If the cup end of the pushrod is failing, inspect the ball at the end of the adjusting screw. If there's a nipple-shaped wear pattern in the center of the ball, the leverage on the cup as the rocker arm moves is the problem. replace the adjuster screws.
Jerry

The bad intake pushrod: do you have free movement of the valve in the guide?

Times change: 50 years ago when my dad overhauled 283s with out taking them out of the car. Honing the cylinders and taking the heads to a machine shop to be rebuilt for 25 dollars a piece. He would put the push rods, rockers and pistons in order so they would go back in the same place. I asked my engine builder about that when he was building my 235. He said we don't do that.

That is a problem all in itself, especially with the 216, 235 and 261 motors. The adjusting balls on the rocker arms wear into the push rod cups. Swapping them around is not all that great and can promote a adjusting ball failure, and maybe even a push rod failure. And that may be part of or the root cause of the bendikng problem. On the other hand, the original solid rods are notorious for bending, and bending for no apparant reason. They were just not that strong. And frankly, they probably did not need to be when new, but now they are really really old, with thousands of heat and cool cycles on them. The cost of a new set of tube push rods is just not all that much relative to the cost of a complete rebuild. And as I notged above, the tube versions are way stronger. I have never, not even once, rebuilt a 235 or 261 without the use of fresh adjusters and new tube push rods.

I have never had a problem with the push rods bending, I've had two (one intake one exhaust) the top concave area has broken. Metal fatigue.