A boys first broken pushrod.... LOL

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Shane

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Hey all...

I'm broken down, and am just hoping its simply a busted push rod, tow her home and put a new one in..

What happened:

The car , 340, comp cams 268, 750 double pumper, .40 over, 2000 miles on a new build , has been running top notch. I haven't really got on it too hard, just been enjoying cruising...

I went for a nice drive this mornjng as I'm up at Lake Erie for the weekend nd about 15 mins out I hear something is not right...

I limp back and this is what I found.

Is it possible the rod just broke and all else is fine, or am I going to be into bigger problems?

Thanks for any input!...
 

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based on what i see in that pic (mind you im on a smart phone) the pushrods are too long and its possible you had contact.
 
What baxter61 said is a possibility. The pushrod cup may have made contact with the rocker.
 
Baxter61 said:
based on what i see in that pic (mind you im on a smart phone) the pushrods are too long and its possible you had contact.
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x2

Pushrods "as a rule" do not "just break."

The ones in my little really mild 318 have been.............

unknown miles in the original 273

In the 340 used to be in my old FJ-40 Landcruiser, UNTOLD "blings" past 6.5--7K
 
They do kinda look deep in there...

They are comp cams rods and mopar rockers...

The car has been running good, I guess I should go back and question the machine shop about it...
 
Maybe just me but something just doesn`t look right on that shaft either.
Looks drilled or burred through to and beyond the plug, that could be a serious oil leak?
 

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Something caused that rocker adjuster ball to starve for oil and burned it up. When it wore deep enough, the pushrod cup made contact with the rocker and snapped the cup off. That whole rocker shaft needs to come down and be inspected. I would do both. I would replace those BS self locking adjusters with good Crane ones. You're going to have to find one adjuster anyway. You may as well replace them all and do it right.
 
I have a few extra rockers, but I'm not opposed to changing them out for something better. What would I order? Does crane sell a whole shaft that bolts right up on my head?
 
looks to me like the push rods are to long...look at the one next to the broken one.it's to close to the rocker.you might be able to shim your rocker shaft, replace the broken push rod,adjust em all and go cruizen...

i hope so anyway...good luck!

i run those stock 273 rockers on a lot of 340s with no problems at all....i have a 69 340 i built 17 years ago with tons of drag strip passes and road miles....never even had to adjust em.
 
Mike , that's what I was thinking when I put them in...

The shop put in comp cams push rods... Should I just get the right length ones from Chrysler? What push rods are you running?

Thanks!
 
mopar head said:
Maybe just me but something just doesn`t look right on that shaft either.
Looks drilled or burred through to and beyond the plug, that could be a serious oil leak?
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FIRE YOUR ENGINE BUILDER!!!!!!!!!!! That notch on that side should be DOWN and toward the center of the engine!!!!!!!!!!!!!!!

That notch is an index mark to properly orient the shafts so the oil holes are in the right orientation.
 

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Are you kidding!??? So you think that simply not enough oil was getting to the rocker and it dug into the pushrod, then snapped off when it touched the rocker!?!!

Like I mentioned. I have spare shafts and a few extra rockers... Maybe all I'll have to do is inspect everything and buy one new push rod...
 
No, LOL that ain't all. You need to inspect ALL of both shafts, rockers, pushrod cups and adjuster balls for damage.

THEN figure out what to do about the pushrods that are too long. You may /may not be able to ship the shaft.

Frankly if your so called "builder" made such basic mistakes as this, I'd be tempted to pull the whole damn engine apart and inspect it.
 
How do I figure out for myself what length pushrods are supposed to be in there? So I know before I go have a chat with them first thing Tuesday morning..
 
Shane said:
Mike , that's what I was thinking when I put them in...

The shop put in comp cams push rods... Should I just get the right length ones from Chrysler? What push rods are you running?

Thanks!
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usually you can look at the top of the push rod and see tiny marks on the edge of the cup from contact with the rocker.i would be leary of all of the push rods and replace them.i use comp,stock and whatever kind is laying around on a street engine.

the 340 i've ran so long has a hydraulic cam and stock 273 rockers and shafts....and i'm pretty sure comp push rods...butt,my adjusting nuts are almost bottomed out in the rocker.i think i have .030 shims under tha shafts.

i would try to get the cups further from the rockers however you can...shorter push rods or shim the shafts,and go from there.

that notch on your shaft is in line with oil holes and as 67dart273 said should be down....the way yours is you are oiling the no pressure side of the rocker.

mike
 
Ok.

I will. I'm having it towed home Monday night. I got some fishing to do, and I can't let this ruin my weekend off.

I do appreciate all your help
 
Where would I get shims? It seems that I can inspect everything, make sure both shafts are facing the right direction, install one new push rod, and be back on the road fairly cheaply....

And then get some pointers how to set the valve lash of course...
 
I would take it back to the builder, and show him the article on how to properly install the rocker shafts. That way if you run into other problems maybe he will make it right.
 
Cruzin said:
Rob, I hope I don't have this problem with my rockers.
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You won't because, 1) I'm tearin um SLAM apart to make sure there are no obstructions or gunk inside them and 2) you're gonna get some good Crane adjusters. They'll be bulletproof when I'm done with them. What happened here is lack of oil.
 
I looked, the other side has the grove on the shaft back at the firewall, BUTT, it too is facing up.

Does having that shaft upside down cause te lack of oil that caused it to break?

Rusty, do I need just crane rockers? And they go on those shafts?
 
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