Ford 302, 10.5:1, headers, Edelbrock intake and 600cfm carb, new rebuild. Managed somehow to snap my oil pump drive shaft last week but luckily was watching my gauge. Pulled dizzy, stock shaft snapped , fished out most of it. I have to pull engine to pull pan cause of my front clip so I just stuck a speaker magnet to the bottom hoping the 2" piece lying in there will never bounce up (highly unlikely unless I am upside down somehow). Anyways, since I am lazy I decided to put a ARP shaft without the retainer clip in through the top and I thought I would share my little trick. Went to McDick's and grabbed a few straws, attached to new shaft with a few slits, lowered in until engaged, took clothes hanger and kept pressure while pushing off straw. This was a new build, no idea why it snapped, thank god it is running fine again. NEVER put in a cheap aZZ ford shaft guys, junk.
I snapped a few at the track. Infact, one spent the season at the bottom of the pan.... I ran a high compression 351 W(15 to 1) and she would snap-um when I wound her near 9500rpms. So I went to a titanium shaft before I went dry sump. The titamium hold up well, but I my envirement was to harsh.... If you snap one again, consider getting the oil safety setup, where a bladder discharges oil into your engine while shutting down. Its works like a kill swtch triggered by no oil pressure. It kills the ignition and discharges say 1/2 qt into an oil passage to keep from whipping and journal..
I broke a shaft two weeks ago. found a small piece of metal in the pump. I can't think of how this metal piece got in the pump. one guy sayed it had to come from the filter. but the filter is down stream
I wound one up like a pretzel-it then broke. A very small piece of the old phenolic timing gear had worked its way between the screen & the baffle on the oil pickup. That piece got into the oil pump & locked it down. The screen ass'y had been hot tanked during the rebuild but when I started looking for the cause I removed the baffle & saw other pieces of the phonelic which had become trapped between the screen & the baffle.
Sure hope my pump isn't pooched. Might be well worth my while to pull the engine and pan and take a look downstream of that screen.
The trick with the straw is neat. Next time, why not put the oil pump shaft into the dizzy with some silicone and insert the "unit" into the engine.
I remember years ago ford had a problem with the o ring valve seals would get brittle and brake up and a small piece would make it's way into the oil pump get between the gears and snap the shaft or shear the pin holding the gear on. seen a few times. bill
It's been a problem with Ford engines since the 289. When I lived in New England many years ago, it was not uncommon on a very cold morning to rev up the engine before the oil got hot and twist off the shaft. I have torn down more than one engine with pieces of shaft in the oil pan.
Ford uses an internal gear gerotor pump... ...in the Windsor engines. The design is unforgiving for foreign material, which can jam the rotor and cause the shaft to shear. SBCs used an external gear pump. A bit more forgiving on foreign material. A hardened shaft may not twist/snap but it may cause the cam/dist gear to break some teeth off if the pump seizes again. May be worthwhile to maintain the stock shaft with a safety system like mentioned by mustang6147.
Another preventive trick involves modifying the oil pickup screen to prevent foreign matter of any large size getting into the pump. OEM manufacturers put a hole, maybe .500-.625" in the screen's center, with a ring locked around the outer edge of the hole. Then a strap is spot welded across the face of the pickup and contacts the rim of the center ring. Then when Hairless Herman, the demon commuter, lets the oil sludge up from not keeping the oil changed, the suction of the pump pulls the screen inward and away from the rimmed hole, allowing the pump to suck oil thru the hole, avoiding oil starvation. High rpm and resultant high pump suction can also pull the screen inward even in the absence of sludge. Good failsafe setup, but any foreign particles nearby also get sucked in and can jam the pump, causing the shaft to shear in an SBF engine or damage the pump itself in systems that don't have the shaft as the weak link. Snip the strap off a new pickup assembly, fab a disc to fit over the hole and silver braze in place and you have cured the problem. Just be sure to keep the oil changed and avoid high rpm with cold, high viscosity oil.
I like the oil safety setup, and I am going to have to look into one of those in the near future. So correct me if I am wrong but does the dizzy not have a shear pin that should fail before the teeth start to snap in the event that my ARP shaft does not fail quickly if my pump locks up?
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