Packard Forum Index » V-8 (1955-56)

what's the reason for the up dated plate, ?

this off my 56 400,

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There is a bulletin citing lifter noise between 40-45 mph. The revised plate reduced flow to the timing chain. However, I don't think they understood what was going on because this is symptomatic of a cavitation problem. The vacuum pump in the pan may have been causing the problem or air may been being sucked through at the rear main, relief valve, or any of the other places they tried to put band aids on the motor.

Were I in their shoes I would have first tried duplicating the symptom in the lab and start with lighter oils and run some bypass taps to examine the flow with the motor running. If the oil was full of bubbles then work backwards to find the source.

If we accept that the 56 motors had a better service history than the 55s, and I think all evidence points to that, then I'd conclude that the cam retainer plate change was a part of that improvement.

After probably 200+ Olds oil pump conversions have been sold (and probably installed) and no performance complaints that I am aware, I think that we can accept the problem with lack of oil pressure at whatever engine speed is caused by inferior design of the Packard oil pump. Provide enough oil flow, as the Olds pump does, and it doesn't matter what cam plate (or lifters or filter, etc.) you have on the engine.

Craig

they could of capped the oil gallery,s, and tried a 1/16th and 1/8 inch hole in cap to see what worked, i think the shop plugged henrys, of coarse he removed them,

ford or chev, maybe chry, do plug the oil galley lines

Riki Quote:

Pontiac did this too on lifter galleries and the distibutor gear, so I know quite a bit about restricted oil galleries. It's a "band-aid on a hemorrhage."

Craig

thanks, craig,

nice job on your brake set up,

after all these years, i noticed that the oil filter, goes into the timing area,

i thought it was in line, it must drop on timing chain, if so then , why did packard use the cam plate to oil chain. a known oil leak.

my plan is to still let oil out of oil galley, but i am going to use a plug, and drill a hole in it, 1/8 inch on left side, and under 1/8 on right side, because that slot is open at end.

with oil coming from filter, and this drip, should keep chain oiled, packard talked about the new plate, as being a drip....

1/8" or so on both sides sounds like fairly big holes and a lot of volume to the chain. I don't know what the original size hole was when they had the continuous feed but it was only one hole and they had enough problems that it was replaced by the intermittent feed setup. If you are going with the Olds pump there might be enough volume if all the passages are large enough to take care of that bleed plus the lifters and since they are the main feeds, everything else that is "leaking" but it still sound a bit much.

Quote:

Just asking, why would one choose not use the second design cam retainer plate and spacer?

I had a supply CNC machined some years back, because so few engines had them.

jack vines