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Worn fuel pump rod question.

Started by 71 SE3834V, August 02, 2016, 08:24:23 PM

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71 SE3834V

Ok so I finally get around to looking into the noise I thought was a lifter tapping. Traced it down to the fuel pump. Pulled the pump and as soon as the bolts were loose I knew I had a worn push rod as the pump wasn't trying to press out. I could lay it right up to the block, no pressure required.
The bevel on the cam end was gone and the edge was sharp. Measured at 3.165". Pulled the distributor and the lobe looks fine just looks like a wear pattern starting to show (I have pics if necessary). No scoring, etc.
Now the question of why?
I measured the rod when I installed it last fall during the engine rebuild. If anything it was just a hair under 3.25". I didn't see any wear on the end and I remember the bevel was still there. I seem to remember the bevel on the cam end might have been narrower than the other so some wear might have been starting. Cam lobe had lube on it as well as the rod, fuel pump lever, etc. when installed. Cam break-in was run with Brad Penn 30wt Break-In oil. Oil was changed out at 500 mi. per the rebuilder and Brad Penn 10w30 was installed.

Is there a coating on the rod that once worn away it goes downhill fast?
I was only able to put 50 mi. on the engine before putting it away for the winter in 2014. Did I lose lubrication over the winter?
Your opinions please.
Incidentally the noise was the fuel pump. When the lever is at the end of it's travel it knocks, you might say, like it's not tight to the diaphragm. A new fuel pump and rod has been ordered.
71 Charger SE 383 4V
72 Galaxie 500 400 2V

Chargerguy74

Out of curiosity what fuel pump were you running? I lost about 1/4" of my fuel pump pushrod on the dyno running comp break in oil.
WANTED: NOS or excellent condition 72-74 4 speed shifter boot for bench or centre armrest car, part number 3467755. It's a rubber boot that looks like it's sewn up leather.

WANTED: My original 440 blocks. Serial # 2A188182 and 3A100002

ds440

We had the identical problem on a 500ci stroker engine.  Brand new Edelbrock mechanical fuel pump, the engine only had 300 miles and the car just quit.  Pulled the pump pushrod and it measured just about 3.125". 

We did some research on various message boards and the going theory is that the more recent pumps come with pushrods that have not been hardened (or just the very tips have been).  Once that tip - if it has been even hardened - wears away, the pushrod gets chewed up like an eraser.  Ultimately, we switched to an electric fuel pump, however, we had been advised that Hughes Performance sells a new pushrod that has been hardened.  But I can't speak from experience as to whether it actually works.

And change your oil.  That metal had to go somewhere. :cheers:
1968 Charger R/T, 440 auto.

71 SE3834V

Quote from: Chargerguy74 on August 03, 2016, 12:51:31 AM
Out of curiosity what fuel pump were you running? I lost about 1/4" of my fuel pump pushrod on the dyno running comp break in oil.

Fuel pump or fuel pump push rod?
The rod was possibly the original but the fuel pump had been changed before I got the car so the rod might have been changed also.

The pump I put in 3 yrs ago was a quick purchase because it was leaking one day so I buzzed up to O'reilly's and bought their house brand Precision #M16110 but when I pulled it out yesterday I see it has a M4589 stamped on it which brings up another issue. In researching this now I see the same #4589 used on many brands, Carter, Airtex, Carquest, Napa (which is an Airtex) and most listings say 'except High Performance'. May have been the wrong pump but the only differences I see in the listings for HP applications are the gph & psi (which is all over the place) and what kind connections it has.

Quote from: ds440 on August 03, 2016, 11:34:43 AM
We had the identical problem on a 500ci stroker engine.  Brand new Edelbrock mechanical fuel pump, the engine only had 300 miles and the car just quit.  Pulled the pump pushrod and it measured just about 3.125". 

We did some research on various message boards and the going theory is that the more recent pumps come with pushrods that have not been hardened (or just the very tips have been).  Once that tip - if it has been even hardened - wears away, the pushrod gets chewed up like an eraser.  Ultimately, we switched to an electric fuel pump, however, we had been advised that Hughes Performance sells a new pushrod that has been hardened.  But I can't speak from experience as to whether it actually works.

And change your oil.  That metal had to go somewhere. :cheers:


I've seen on Mancini's site they sell 3 different ones. A standard one, a chromoly tipped one (3.22"), both listed for flat tappet cams and a bronze tipped one (3.242") but no application listed.
At this point I'm going to stick with the standard one. If it happens again with this new one I'll do some more research.
And yeah, it's got 500 mi on it since the last oil change so I'll change it but it's been making this noise for a while so
that stuff been floating around. Hope the filter did it's job. 
71 Charger SE 383 4V
72 Galaxie 500 400 2V

c00nhunterjoe

My opinion, which is just that, is that its all chinese recycled freaking garbage no matter what they claim anymore. Find a used old one or swap to an electric pump at this point. Those shavings will end up destroying your engine after a few failed attempts.

V8-Rocker

Had the same problem with an comp cams pushrod. Junk after 250mls. Now I have the hardened pushrod from Hughes engines without problems...

68CoronetRT

I solved my fuel pump push rod problem with a block off plate.... :D

Dino

Jeff I still have my old Carter pump. I once thought it was the source of my fuel starvation problems and bought another pump which is currently on the engine. Turned out it was something else. The fuel pump is old (ie made well) and should clean up just fine. It's yours if you want it.
Alternatively you can have the pump that's on the engine now and I'll use the old one. The newer pump is also a Carter that I bought old stock and runs around 6-7 psi. The old pump pushes a bit less.
Extraordinary claims require extraordinary evidence.

71 SE3834V

Well thanks Dino. I already picked up the pump but I could always take it back. The bigger issue is if the rod came in tomorrow I was gonna slap it together tomorrow afternoon cause I got somewhere I'd like to drive the car on Saturday. What's your schedule like?

BTW, nice updated avatar.  :icon_smile_big:
71 Charger SE 383 4V
72 Galaxie 500 400 2V

Dino

I'll be home tomorrow evening and I'll be home studying all weekend so you can come by any time. I'll dig up the pump when I get home. Or you're welcome to remove the pump from the engine. Should have easy access to it!

Yeah it was time to update the avatar.   :icon_smile_big:
Extraordinary claims require extraordinary evidence.

71 SE3834V

I think you got the caption wrong. I doubt it's forgotten. More like "Down but not out!"
71 Charger SE 383 4V
72 Galaxie 500 400 2V

Dino

Yeah that might be a better one, although I do forget about it from time to time. I had to get the fuel pump out of one of the boxes inside the cab so I removed the cover to let everything air out a bit. The semester ends on the 15th so I'll be doing a little bit of work on it after that. I think I'll take the hp manifolds to the chem dippers near you, I have the high temp Eastwood paint for them. I still need the hardware but it would be nice to get those in place before the heads start to rust!
Extraordinary claims require extraordinary evidence.

71 SE3834V

If you want I call haul them back with me and take 'em in whenever you want. Save you one trip. I had my rims done there. You'll be glad to hear they're repaving that mile of bad road near me.
If I end up going to Roseville for the push rod I could pick up the hardware kit and save you the shipping.
71 Charger SE 383 4V
72 Galaxie 500 400 2V

Dino

They're repaving? Well that's tax money well spent at last!   :lol:

That would be great if you could take the manifolds, thanks! The hardware would be great as well IF you end up going there. Ordering the kit from ebay is the same price so no worries there.

I'm turning in, gotta get up early to study....
Extraordinary claims require extraordinary evidence.