Oil Pump Drive Shaft - ARP or OEM

Ich habe ein ARP gekauft
Das wurde eine gute Lösung sein
Let's wait for the good answer

After 15 years of exposure to this question, I have read arguments on both sides that make sense to me.

I personally believe the basis for this entire discussion was formed around the reality that the stock ford rubber valve stem seals were destined, over time and with the subsequent heat exposure, to lose their elasticity, thus hardening and becoming very brittle, and then ultimately breaking into tiny pieces. Those tiny pieces made their way through the oil passages and through the oil pump screen causing the pump to jam, with the shearing of the distributor gear pin being the common result.

Some opinions apparently feel the stronger driveshaft may help the pump chew through the small pieces? The other viewpoint perhaps feels that a jammed oil pump should cause some failure - and subsequent engine shut down – rather than pumping small, chewed up pieces through the oil passages.

IMHO, If the Cleveland engine in question is no longer using the OEM rubber valve stem seals, I can see no advantage or disadvantage to either a stock driveshaft or the stronger after market versions.

Flame suit on.

Larry

(1) The OEM oil pump shaft does not shear. It doesn't break. I've never in my whole life known a single person to have their Ford vehicle strand them somewhere due to a failure related to the OEM oil pump drive shaft. Neither have any of you. I can recommend the OEM drive shaft with confidence, knowing my advice will not cause you problems down the road.

(2) On the other hand, I have known MANY people who have been stranded due to the distributor gear roll pin shearing after installation of the heavy duty oil pump drive shaft. Therefore I cannot recommend that part to you, because I have no confidence it will not give you trouble.

(3) The heavy duty oil pump drive shaft WAS NOT designed to rectify problems with the OEM shaft failing, because it doesn't fail. It was originally advertised to prevent "spark scatter". So unless you are experiencing problems with spark scatter, you do not "NEED" the heavy duty shaft. I don't even know what the symptoms of spark scatter are to describe them to you.

(4) The heavy duty shaft is the solution to a problem you didn't know you had.

(5) On the other hand, if you like being stranded on the road, if you like paying tow bills, be my guest.

There's a saying "if it ain't broke, don't fix it". Besides, for the price of that shaft I can purchase a nice bottle of Scotch Whiskey.

Ever wondered how much it takes to snap the OEM shaft? Quite a bit.

See below.

quote:

Originally posted by LF - TP 2511:

... Flame suit on ...

I like the barber pole look. Can I have one for my car. Looks cool..........

Dear Larry and George,


There may be some thread drift here, but this discussion reminds me of something that I recently heard about this very topic. The topic was oil pump drive shafts. My very experienced friend asked me why I was using a big thick aftermarket drive shaft. I replied that *all* the reference texts and "everybody" said to upgrade to one rather than the "weak" stock Ford shaft. He told me that it was his opinion that this "truth" of Cleveland engine building may date back to the early seventies. Ford cars with high performance Clevelands running thick high viscosity oil (common at the time), would induce high loads with the high rpm launches and the relatively cold thicker oil leading to some failures that became the foundation for the myth of the bigger is better Cleveland oil pump drive shaft. Perhaps, now it can be told.....? I find this plausible, but still hearsay.


Warmest regards, Chuck Engles

I appreciate the input Chuck. I don't remember the oil necessarily being all that high viscosity. We ran 20W40 and its replacement, 20W50. BUT I remember a lot of guys adding STP oil treatment to their engines; now that stuff was thick!

I kinda think the little shaft is just a bit of consumer fraud, an easy buck for someone to make. Along the same line as an old oil additive named Slick 50. Remember that one? It cost $49.95, a slick way to make fifty bucks. One of the most blatant, slap you in the face consumer frauds I've ever seen.

Talk about thread drift.

Wonder why nobody has ever produced a gear pin out of cryptonite, how can this problem still not be solved?

what would be the thought/reason that the HD drive would contribute to gear pin shearing?

George, was that twisted drive failure a shop test or did that happen in the engine?
(edit;never mind, I googled and saw where that does happen)

(the thinking is....)

The softer (more malleable?) steel in the stock shaft does twist if the gearrotor pump binds on a small chunk of debris, and thereby reduces the instantaneous load on the distributor pin.


Regards -

Rocky

quote:

Originally posted by No Quarter:
Wonder why nobody has ever produced a gear pin out of cryptonite, how can this problem still not be solved?

Ah, but they have solved this problem. They have designed motors with crank snout driven oil pumps. They no longer shear pins. Now they just shatter the gears themselves.

The stock 351-C dizzy gear drive pin WILL fail for a number of reasons, even in stock engines (if there is such a thing after 36 years and many unavailable stock parts). If the drive pin is strengthened by any of a number of techniques, the next weakest link in the chain of parts is the stock oil pump driveshaft. Ford sells (or once did sell) one that works well under even racing stresses.

Note- the same drive system is used in the 289, 302, 351-W and 429/460/510 Ford engines as well as the various Cle-vor blocks. I have no data on their failure rates, but high rpms seem to be part of the overall problem.

A second thought- the 351-C oil pump gearotor set is much taller than any of the other engines including the famous 427 FE side-oiler. it is possible to retrofit the Cleveland gearotor set and pressure pop-off into other oil pump bodies, but an extended cap must be built to accept the big gearotor. I believe the aftermarket Titan racing aluminum oil pump uses a stock Cleveland gearotor.

I have the same Moroso heavy duty drive rod for the last 20+ years, through 5 engines, the last build I replaced the bronze gear with a bi-metal gear on the distributor and did not use a double roll pin and the pin shirred. their was no oil pump problem just the torque on the gears over time (6 months ) fatigued the pin to break. If you are running a stock engine with small mods like a intake or headers your alright, it is when you add horse (over 400) power things break.

The "barber pole" rod was a catastrophic (jammed) oil pump failure. In fact I had referring to the above post, the hole drilled larger to accommodate a big pin and a bronze bushing to stop any up or down play in the shaft.
This distributor is only for running the oil pump and has the head cut off,I run a crank trigger.