Oil pump eaten up and destroyed

[unclewill]

So I bought another used donor 390 for parts.  I started to tear it down and noticed it had hardly been run, the bottom end looks brand new!  I was also happy to see a Melling HV oil pump in there - score!  But alas, I pulled the pump and tried to turn it and it was locked.  I also noticed the pump drive shaft was stuck fast in the distributor shaft - I mean it will not come out!  Removing the bottom cover of the oil pump reveals the small gear was driven so hard into the cover plate that it ground chunks off of the plate and locked itself up.  So...lesson learned to always check oil pump driveshaft clearance!
Anyone care to share a procedure for doing so?
Thanks!

[machoneman]

Odd that the pump was locked up yet the main and rod bearings looked fine? Did you check every bearing and the thrust surfaces on the center bearing and crank thrust faces? How does the bottom of the distributor gear look as well as the cast iron 'shelf' inside the block that the gear rides on? Pic of that shelf btw: http://diyford.com/wp-content/uploads/2013/11/332.jpg
 
With a new pump, bolt it onto the bare block, add the pump driveshaft, mock up the
intake and install the distributor with the hold-down plate w/bolt tightened down. The drive shaft should move up/down at least 1/8" to 1/4", essentially free play where the shaft doesn't bottom out. Add the ditzy's rotor and w/o a camshaft installed, the rotor and hence the oil pump should very easily spin over.   

One other thing to pay attention to:

http://www.camresearchcorp.com/shop/uncategorized/distributor-gears/

The Ford link explains the why but note the dimensions given are not for the FE! The Camresearch link has the correct ditzy gear height for all FE's. 

http://performanceparts.ford.com/download/pdfs/DistributorGearInstallation.pdf

[unclewill]

Thanks for the reply Bob!  I'm too busy with the 482 to bother checking the bearings on the 390, but I am planning to finish tearing it down one day if I don't sell it first.  I'll also check the surfaces as you describe.  I'm not sure if it killed the engine, the guy sold it to me as a runner (as they always do!).
I'll use your method to make sure the sideoiler doesn't end up with the same problem.

[babybolt]

I'm betting that the builder of the core engine inadvertently installed a 429, 400M or other longer oil pump drive shaft instead of an FE.   

[Heo]

I dont know but i think the coverplates is made out of
a little to soft material. Just stamped out of some mild
steel.When you open a new pump they are already scratced
 I shall try to case hardening one coverplate

[machoneman]

I'm betting that the builder of the core engine inadvertently installed a 429, 400M or other longer oil pump drive shaft instead of an FE.

That's kinda' what I thought too Babybolt. Light scoring as Heo stated is normal but it sounds like our poster has a really torn-up plate. Unusual to say the least but yes, a too long shaft would do that. 

[fekbmax]

That could deff cause some probs. 1/4" v 5/16" . Like jamming a square peg into a round hole. Lesson it's a 361 - 391 dizzy/pump combo.

[blykins]

I'm betting that the builder of the core engine inadvertently installed a 429, 400M or other longer oil pump drive shaft instead of an FE.

Bingo....

A pump shaft for an engine with a girdle.....maybe an MEL shaft, etc.  I've never had any issues with the correct pump shaft being too long or the gears in the pump bottoming out against the cover.

[unclewill]

I'll check it and get back to you, sounds plausible to me too...

[unclewill]

Curiosity got the best of me so I started working on the 390 unilite.  The pump drive shaft was seated in the diz shaft then someone drilled and inserted a small pin to hold it in place (which is why I couldn't remove it at first).  It is the correct length shaft, though.  Is this a common mod?  I'm not sure how this would cause the problem with the pump.

[machoneman]

No, it's not. Pinned shafts are not used.

FE's (and pretty much all Fords) use a retaining clip as pictured below.

https://www.summitracing.com/parts/slp-224-61114?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-sealed-power&gclid=CJm0tOj9rdECFU-ewAodc4ENzw

[cammerfe]

Since the first time I pulled a hex shaft loose and dropped it into the pan (sometime in the 1960s) I've put a light drop of Loctite in the end of the diz. Never failed me yet or caused any sort of problem with the pump.

KS

[unclewill]

I can't think of why the pinned shaft would matter, I'll post any new findings as I deal with the 390 in the future.