Packard Forum Index » V-8 (1955-56)

IIRC the Hash pump has SHORTER gears than the Packard/GH pump. So the PI pump would be my preference. NOTE that u indicated: " Assuming they are both within wear specs,..."
I AM assuming that quotation.

JUst for kicks here are some pics of the various pumps. SCROLL UP to top of page:
packardinfo.com/xoops/html/modules/newbb ... orum=3&post_id=85813#forumpost85813

Thanks Jack & PV8. I cleaned up the Hash pump (sludgy and the relief piston was stuck). It cleaned up nice and the gear to body clearance is .002, gear to base is .004 ...both well within spec according to the 1955-56 shop manual for a Packard pump and I assume that would also be within spec for the Hash.

I should have time to open up the 374 in the next few days and I'll look at the PI 56J pump. It only has a few thousand miles on it tho it has been sitting for several years

Measure the gears!!!! IIRC the Hash gears are at least 1/16" SHORTER than the Packard/56J. Maybe 1/8". Otherwise they are identicle.

Packard8 Quote:

Good catch! I believe this is the "fatal flaw" in the Packard V-8 oil pump design which causes lifter clatter and later engine failure if it continues.


I'll start a new thread on this when I have all my info and pix together.

Craig

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Will do & post the results.

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Yes, that sort of surprised me as the bottom end of the motor looks fairly clean. The relief piston was frozen closed and I had to tap it out with a drift..not sure if that would starve the lifters??? Wire wheeled the piston and cleaned the bore with a brass rifle brush. Lubed and reassembled it and it works smoothly now. Also there is a passage between the 2 chambers in the base of the pump (intended to lube the gears?) and it was completely blocked with sludge.

This motor was set up with the road draft tube connected via a rubber hose to the oil filler tube....a "closed loop" system guaranteed to sludge up an engine! I'm changing that so the road draft hose is directed to the flame arrestor (air cleaner) and the vapor will be burned off.

The critical pump spec is the INPUT SHAFT to pump body clearence. IIRC manual indicates .004" MAX. And that .004 is probably very generous based on my analysis for the PACKARD V8 pump. Also watch for excessive wear on the shaft directly at the top of the gear. The Hash will most likely show no wear while the Packard and 56J pump WILL show wear.

Personally i would NOT alter the road draft tube in any way from OEM design whatsoever.

Refresh my memmory. Are u building this engine for a car or boat???

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The engine is a marine conversion. Re the road draft tube, it was altered from the original design.... instead of venting under the car they routed crankcase gasses back into the oil filler tube. I assume this was done so the fumes would not build up in the bilge or engine doghouse. I have changed this so the fumes are recycled thru the carb and expelled out the exhaust.