My 1000-Mile Melling Oil Pump

The pictures pretty much sum it all up.

 

well....Golly.
Id say that you might have a touch of a problem there.

Im no expert, but somthing is defiantly out of place.

Whats the bottom end of the motor look like?

 

If I didnt know any better , I'd say that this is the result of a pump that has been installed dry ( not preprimed ) then the cavitation process stepped in , allowing partial oil air mixture , thus not being allowed to compress the air , resulting in the shaft being broken

have heard of this exact same thing happen a couple of times


cheers Steve in Oz

 

Never seen a shaft twist that much before breaking.

 

That is one cool garage trophy.

 

That's a perfect twist.

 

Ouch! That hurts... A buddy of mine lost a built 455 Olds in his Donzi with a mellings high volume pump while it was idling at the dock... Turns out that below a certain RPM, it would lose it's prime... Wonder if that's what happened?

 

something locked the pump up. Ford pumps can't pass even the smallest piece of trash like a GM gear pump.

 

I saw a Mustang do that once to a shaft.

 

I took one out of an old Ford 240 engine, looked exactly the same. How does it know how to do that?

Bob

 

My guess: when distributor was tightened down, it loaded the pump drive shaft, against the pump gears................i.e.: The distributor / pump drive shaft combination was too long............I don't think the twist happened in use, ( might be wrong), but it looks too perfect to have happened in service...........

 

Almost looks designed to transfer oil up to the distributor bushings. Twist's as good as Chubby Checkers!

 

stealthcruiser, I think you are right. the eng is a small block ford. something got in the pump to cause it to twist ,then snap.Looks like a dist cap clip.How could that get past the screen? I tore down a sbf that had oil and water mix, and the shaft was twisted like that.

 

Had the SBF in my sons Mustang do the exact same thing a few months ago with a new Melling pump and shaft. Didn't have 50 miles on it. I'm sure something got into it but I couldn't see a thing. Wiped out the new crank bearings too. Same distributor went back in, and it's still going strong.

 

I think there's more to the story than pump failure. Something else happened. The end cap shouldn't have had that much thrust wear. I could be wrong.

 

Are you kiddin? that twist is way too perfect to happen in non red hot condition!
I mean, i used to twist metal bars for my lowrider bikes and that is tooooo perfect
for being cold twisted...or it might be a soft alloy and then i would understand...kinda.
But why should a pump have a soft alloy crank should be the next question then
What do i know of phisics anyway?
The end cap has sum serious thrust also!
So, you done playing w/ our minds and wanna tell us?

 

Sabotage!!! plain an simple.
One of your buddies,,,,,isnt !
I'd conduct an investigation.

 

Cool, I mean sorry for your loss, but that Indian Larry drive shaft is too cool!

I had a small block mopar once where on a new oil pump the hex socket in the drive rotor wasn't as deep as the old one and the intermediate shaft bottomed out. We caught it when the distributor wouldn't stay tightened down. It scored up the cover like that one is. A new pump and a shortened intermediate shaft solved the problem.

 

That's common on small block fords, if an debri gets in the pump the shaft twists and breaks. I had it happen when a snap ring broke off of a roller rocker and the piece got in the pump.

They sell hardened shafts for the SBF, and say to run them whenever you run a high volume pump because the extra pressure will twist up a stock pump drive.

 

yeah, looks like an"extra" distributor cap clip got in there. Stuff always jumps down the dist hole. How many times have you heard that pump driveshaft fall into the pan when you pulled the dist...they always put the clip end upside down......

 

Exactly Bryan you read my lips!

 

I had an early experimental 460 ford, that's what it said on the window sticker, anyway when the valve seals became hard after awhile they cracked and fell into the pan and the pump sucked them in and jamed it tight, breaking the drive and dist. gear. Took it apart and no screen what so ever on the pick-up. Was out of town and found a junkyard full of 429 big fords and mercs. 9 out of 10 had the same problem when I went to pulling dist. for the gear. Found one good gear and used a long allen wrench cut to fit and screened my pick-up. Worked perfect. That shaft of your's had to be soft to twist like that when the pump locked.

 

Damn, am I glad I don't sell Melling oil pumps! The emphasis on the thread title would indicate Melling was at fault....it isn't/wasn't, something caused the pump to fail, it was not the oil pump itself. As, many have stated, it was locked up due to some sort of debris. Be sure to correct the real problem, before going forth.

 

Just wondering how long did your engine run with no oil pressure? Might be alot more to look into.

 

That sucks

 

I don't think you can imply anything related to the cover being scored up with that piece of debris. Nobody really knows how long the debris was trapped in the pump, or how long it tried to enter before it actually entered. It very well could have been mashed between the gears and cover for a while, or trapped on the other end of the gear causing thrust.

The reason the twist is so perfect is it had continuous force, just like a manufacturing process. Trying to twist bars at home you'll never have the consistency of force. In fact the even-ness of the twist shows that the drive rod was very consistent in terms of metallurgy and inclusion. I've seen one just like it that came out of a high mile 302 that had the gears jam due to a carbon chunk.

better luck next time

 

What was said in an earlier post about Ford valve stem seals getting hard and cracking apart is correct. The oil pump pickup screen has a strap across the middle. Sometime when you find an old screen laying around, take snips and cut the strap on one side and pry up the strap.
Under the strap you'll see a hole in the screen, usually finished uo with a stamped ring around the hole that is meant to seal against the backside of the strap. The intent is that if the screen gets clogged with sludge suction will pull the screen up and allow oil to get to the pump thru the hole.
Get that engine in a high rpm situation (maybe a kickdown to a lower gear in a passing mode, etc.)with a partially blocked screen and it will pull the screen up and any debris present (chunks of valve stem seals) will get sucked into the pump. Then what we see here happens, although I've never seen one twist so symetrically.
Learned long ago when touring salvage yards in search of a rebuildable SBF core that the next thing to check after visible damage or missing parts was to pull the distributor and check the oil pump drive shaft.
Dave

 

I don't think it being a Melling pump had anything to do with it failing. Who dropped that metal clip in the Pan?
The Wizzard

 

i had a 62 falcon that that hapend to also the first time i changed the oil and lost the prime. second time i found a piece of rubber in the pump.

 

Thats what I said!! Pist,, It's a Mystery!! Heres a home detective kit!! I hope you catch the culprits. LOL
http://www.scribd.com/doc/429023/Detective-Kit