Stuck Oil Pump!?!?

[Jon Miller]

First it was rings....Now it's the oil pump.

After about 40 minutes of run time my nice new Mellings High Volume oil pump ground to a halt and twisted the pump drive shaft in two. The parts that turn inside the pump ground into the plate on the bottom of the pump until it stopped turning. I promptly ordered a new pump and drive shaft which I hope will arrive on Friday. What I need to know is why this would happen in the first place? I would rather not keep replacing pumps every 40 minutes, although it would serve to keep the fuel bill down. Could it be that there was pressure from the drive shaft forcing the impeller thingey down into the bottom plate? This is my first FE, maybe it's normal to replace oil pumps every 40 minutes or so.......Maybe I should have gone with the 289.

In other news: The rings are still soaking in Marvel Mystery Oil in the hope that they will unstick, and I'll be back up from 6 to 8 cylinders without the need for a complete tear down. I did get a compression increase from 40 to 70PSI on one of the cylinders. The other is still at 25 PSI.

-Jon

[Ron61]

Jon,

I haven't used the Mellings pump but all I have heard about them has been pretty good. Did you call them and ask about that? Is is possible that you received the wrong drive shaft and it was just a little to long and that forced everything down inside the pump?

Ron

[JBCOBRA]

WOW! That is horrible.
Who built the engine?
Can you just send it back?

[Jon Miller]

I think I figured it out......I dumped 2 ounced of WD40 in each cylinder in an effort to get the rings unstuck(See "Stuck Rings" Thread). I let it sit for a few hours, then ran the motor. That's when the pump broke. What I'm thinking is that a good portion of that 16 ounces of WD40 made it's way into the crank case, and got sucked into the pump in one big bubble. Since it's 90% solvent it removed the lube from the pump and allowed it to destroy itself.....Since the motor did not start making terrible noise, I don't think any other damage was done.

Thanks,
Jon

[Jac Mac]

Replace your oil filter, if your lucky most of what got ground off in the pump should be in it. If your down to 25lb in one cylinder most of the unburnt fuel in that cyl will be diluting your oil as well. I dont mean this in an unkind manner, but with all the time you have spent on these issues you could probably fitted a new set of rings. Sometimes the long way is the short way!

Jac Mac

[Rick Parker]

If you are using the ground HP oil pump shaft, they can be installed incorrectly. The Hex is longer on one end that the other (?) be sure it is installed with the right end in the pump vs the distributor.