Keep blowing oil pump shafts!!!

[Na5.0HO]

OK... blew an oil pump shaft... rebuilt the motor (except short block) with all new gaskets etc... got it running again... blew another one!!! WTF ?!?

So, what do you guys think... clogged oil pickup?? clogged oil galley?? Possessed demon engine?

What would you guys do...?

Thanx,
Pedestrian Jason

 

[2muchtime]

do you have a high volume/pressure oil pump ? stock pump drive?
what do you mean BLEW ANOTHER ONE ?
twisted ? snapped in half ? shattered into dust?

 

[Na5.0HO]

I have a Mellon high volume pump and not sure what u mean my "stock pump drive"... the first one twisted and then snapped in half and i assume i did the same because i just lost all oil pressure, my valve train got loud as ***** and the smell of burning oil...

 

[2muchtime]

(pump shaft) oil pump drive
high volume melling oil pumps cause way more stress on a pump drive
may or may not be your problem did you replace the cam, timing chain, and all that?
the only things that will cause your problems are- something is seizing either distrubutor, oil pump.
error installing camshaft (walking,tolerences)
or to much horsepower
if your going to go with a hv/hp oil pump use a ford racing pump drive
but if your asking opinion on the oil pump, i would put a stock one in
seeing your motor doesnt need 50/90 lbs. you are actually losing horsepower having to drive a higher pressure pump

 

[Na5.0HO]

I put in an E303 cam and used an Edelbrock timing chain... I have alot of friends using that oil pump so I assumed it would be ok... it did the exact same thing that happened last time... started ticking for a while and then just snapped, so i assume is isn't related to the cam, timing chain or anything I replaced... still not sure?? Thanx for the advice I suppose I'll have to drop the K-member...

 

[2muchtime]

have you asked your friends what they are using for a pump drive ?
the factory ones are weak anyway, a nice ford racing or better drive is
a safe bet anyway..
is it breaking after a few minutes of idling in the driveway ?

 

[Na5.0HO]

Everyone else has been fine with the stock replacement shaft and since most of them are pushing at least 25% more horse then me... I figured it was straight...they both broke after driving around (slightly harder driving, but nothing serious ) I agree that something MUST be siezing, because even a stock shaft with only 250 horse tops shouldn't snap THAT easily

 

[2muchtime]

well if they just started snapping when you replaced the oil pump i would probably try a stock oil pump
if this is an ongoing thing and you replaced the oil pump thinking that was your failure..i would look more towards the distributor end of things..assuming your cam was installed using all the
correct specs and procedures.
keep me informed on your outcome and good luck

 

[Na5.0HO]

Thanx... I appreciate the help

 

[EMW150]

i would put a stock one in
seeing your motor doesnt need 50/90 lbs. you are actually losing horsepower having to drive a higher pressure pump

I agree, definately go with a standard volume pump. I've had great success with the Speed Pro / Sealed Power pumps. My engine sees almost 8000 rpms with a standard volume pump and has held up excellent. The last time I had it apart the bearings looked like the day I put them in. Not only do the HV pumps take more hp to turn, they also pump oil like crazy to the top so you have excessive drainback. Have you pulled each pump apart to see if there's anything in them? Most of the time they twist the shaft due to scrap getting by the screen and locking up the gears.

 

[bmo37]

if i remeber they have a hardened oil pump shaft opposed to the stock one which is for use on a hv pump.

 

[04sleeper]

You do not need the high voulme pump. As mentioned before it will only make you loose HP and it sounds like it might be the culprit anyways. Just because your friends have them doesn't make them ok. A good stock replacement pump will give you plenty of oil pressure and free up some HP. Then you will have even more than your friends.
Also if a high volume pump is used it pushes a lot of oil to the top of the motor and unless you have a bigger oil pan like a 7 quart you might actually be starving your main bearings. Not Good.

 

[dastang2]

i have the same oil pump and it came with a oil pump drive. i think you just got a bad pump. i am about to switch to a regular pump because i suspect i now have bearing damage or the pump may be weakening. i am using oil that i was told is too thin. 10w30. i was told to use 20w50. now it is hot in texas and when the engine warms up, psi drops to 20 or below at idle when at cold is at 35. hopefully bearings are good but it really don't matter, they are not expensive.

 

[Na5.0HO]

Thanx guys... I'll prob switch back to a stock replacement, however, the first one that broke was stock and this one blew after 200 miles of putting it back in the car after the first one went. Because of this I am thinking there must be something besides the pump itself that is freezing up...