Hello everyone, I recently pulled the head on my 228 to replace the gasket and upon looking at the pushrods, I noticed hairline cracks on the outside of the cup on the rocker arm end. Ten out of the twelve have them. The two that don't are a different style and look like they replaced old ones at some point. I'm assuming that any cracks are not acceptable. Would reusing them risk catastrophic failure? I would guess that they could start chipping at some point. Anyone else run into this problem?
If they are indeed cracked then yes, you are risking a failure. Time to replace them. Just be aware, that all push rods and adjuster balls are not created equal. The cup in the push rod has to match the ball adjuster. If the ball is even a tiny tiny bit bigger then the cup, the ball will essentially sit on outer edge of the cup and will pound the cup rim and then fracture in short order. Blue up the cups on the replacement pushrods with some dykem and rotate the balls in the cup an look at the wear pattern. If its just on the edge, you will have to sort out a work around. FYI, I had this happen last year. I installed a set of Clifford chrome moly pushrods I had purchased 30 years ago. Did not think to check . turns out the cups were just a hair smaller then the sealed power rocker adjuster. Fractured two push rod cups coming home from a show. Blued a couple of the cups and ran the balls and discovered the entire set was running on the edge so out they came.
Ten push rods, all with "cracks" in one engine at the same time? It does not fit the normal manner in which parts fail in an engine. Can you post some closeup pics? It isn't difficult to post pics on this site. As many on this site can attest for me on this, I am old, fat, forgetful, short-fused, homely, inconsiderate of other's feelings, and stupid, yet I can still post pics on this site. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
Thanks for the replies you guys. I did my best to get close ups of the cracks. I've looked over all of them and at least one of the cracks are visible on the inside of the cup. I've also attached photos of the new style rods that were installed. I looked over all the cups and rocker arm adjuster balls and didn't see any uneven wear patterns.
The pushrods are measuring at 10 9/16"(10.56") but I can't find replacements at that length with ball and cup ends. Patricks sells Mellings that measure 11.108". .5" is a big difference that I'm assuming the rocker arm adjustment won't compensate for. Summit does sell another Melling https://www.summitracing.com/parts/mel-mpr-79/overview/, that measures 10.513". Is that close enough, or does it have do be exact? The ball ends are different from the originals ones though. I guessing that is what Dragsix was talking about. Anyone else have input on this? I'm steering in the direction of reusing the old rods. I don't plan on really pushing the engine at all. Just driving it every now and then around town.
Comp Cams sells kits that allow you to fabricate custom length pushrods with ends that match specific requirements. Their website states that you need to contact their technical department to be sure you get the right parts the first time. When Comp was a brand new company back in the mid-1970's, my father was a field tester for them, using their experimental lobe designs in the circle track engines he was building. Two men had left Cam Dynamics to open their own cam grinding company. Their custom pushrod kits come with a set of over-length pushrod tubes, a special cutter tool, and an installation jig to put the cup shaped top piece in straight. I've used them on MOPAR engines with Skorpion roller rocker arms, and they work very well. Call Comp tech assistance to see if they sell a blank pushrod long enough to fit your engine. They're very helpful, and they know what they're talking about. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
You really can't eye ball the adjuster and cup contact pattern only because you don't know whether the push rods have been moved around or replaced or replacement adjusters installed. You really do have to dab a little machinists dyekum on the cups and run the ball in on the cups to confirm. Byw, those cups look pretty rough inside. What do your adjuster balls look like. That may be part of the problem. As for reusing push rods that have obvious cracks, that would not be the road I would choose. When those cups break or shatter, the ball can jam up the push rod, the pieces can fall into the push rod boss, then into the lifter galley and if you are really unfortunate, into one of the drain back holes to the pan. The issue with the push rod jamming up the rocker, it could jam an intake valve open, and a piston could hit the intake bending it. Now you have a valve job to attend to. I was lucky, when mine shattered it jammed the exhaust valve open so all I lost was compression. Smith Brothers in Oregon makes push rods and matching adjusters for all kinds of motors, including the 235 and 261. They made me a set for my 261 and the quality is just tremendous with the adjuster balls perfectly machined matching the push rod cups. The downside, they are somewhat expensive and the smallest diameter rod they make is 3/8.
If it were me, and I know its not, lol, but if it were, I would be patient and hold out until you find a new set of adjusters and a new set of push rods. Or, do as Jerry has suggested, purchase the kit and make up some new push rods. In either case, blue the cups up and confirm correct seating of the adjuster ball into the cup.
So those measurement lengths are from end to end? How does that reflect on the actual seat? I am guessing the ones that are close may be much closer when looking at the actual seat?
I was thinking that after you use machinist die and are not happy with what you see, could you use valve lapping compound to seat the ball and cup to satisfaction?
I ended up with the Mellings MPR-31 rods. I was confused at first since summit listed them at 10.444" long. When I went on Patricks website he listed rods at 10 9/16"(10.5642"), which ended up being the MPR-31 rods. They measure up nearly identical to my original 228 ones. The rod shaft is thicker. The original being 1/4" and the MPR-31 is 5/16".
