Packard Forum Index » V-8 (1955-56)

1.Is there any known history of the engines???
2. how many miles are on the engines?

FWIW, remember, this engine has perfect oil pressure, as described in the initial post. How then does it have an oil pump problem allowing the lifters to clatter enough to require a flat bed ride home? Lifters click and clack. They don't make the "sharp metallic rap" like a big ball pein hammer hitting iron. Spun rod bearings are not common on Packard V8s. Could be a rod, but the main bearings usually fail way before the rods.

Don't guess. Do the diagnostics. Pull the rocker covers. Pull one plug wire at a time. Let us know what you find.

thnx, jack vines

I'll await the autopsy results but stick by my earlier opinion that it's bearing trouble, "whacking" and "metallic raps" are not the sounds of lifters. However on rethinking it, I agree with JV that it's more likely a main than a rod.

And it will be interesting to see if the CENTER main is the worst one of the bunch.

Jack. Have u noticed in any great percentage of your tear downs that the center main seems to be worst most often????

It is usually the three middle mains which are the worst first, but I've seen all five into the copper. I'd say 80% of Packard V8s have had main bearing replacement and the crank turned .010", but less than 50% have had rod bearings. I have found one with .003" oversize piston pins in STD bore pistons. I have yet to tear down an engine which has been bored oversize. Every Golden Hawk engine had evidence of a dropped valve. One had a sleeved cylinder, one had the entire top of a piston gone, one has nicks in the bottom of a cylinder bore, evidence of either a broken piston or thrown rod. The OEM Packard intake valves are just too heavy for the springs. Add the problem caused by the first-generation retainers being too soft and it didn't take many races to drop a valve.

thnx jack vines

JV writes :
" I'd say 80% of Packard V8s have had main bearing replacement and the crank turned .010", but less than 50% have had rod bearings..."

Any idea as to why the mains wear so much faster than the rods???? I wouldn't think oil delivery is a problem since the mains get oil FIRST and then the rods second. What do u think it is??

mikec -

It's difficult to describe a sound with words, but if it's coming from a single lifter, I suspect it would be making noise at half the rate of the engine RPM. Bottom end noise would be at the same rate as the RPM (faster), but rod bearing noise can be twice that (because of the up-down stroke).

I'm no master motor builder, but I've found that when these cars have spent a long time (years/decades) unused, they will exhibit some lifter noise that can be cleared up after a couple of oil changes, each with a dose of STP. That hints at a build up of varnish in the lifters.

If you are concerned for catastrophic failure, you should remove and inspect the lifters. Then, drop and clean the oil pan (and pump strainer) and check the main and rod bearing clearances. Report back with your findings.

Yet, if you have good oil pressure, I doubt if those bearings are the issue.

BH writes:
" Then, drop and clean the oil pan (and pump strainer) and check the main and rod bearing clearances"

Yes, the oil strainer always amazes me. My very original and very low mileage (34K miles ) 56 Executive had good oil pressure but a strainer that was nearly plugged solid (on the outside of the screen) with gasket material, a little sludge and mostly broken pieces from the valve seals that got hard and broke up.

Ditto for my high mileage (115K miles) but very original and rusty other 56 Exec.

BOTH of these engines had good oil pressure 40 - 45 psi. The high mileage parts car had 60-65 psi oil pressure with a nearly completely plugged screeen but that was due to a stuck PR valve and extreme sludge build up thru the entire engine.

So u mite want to consider to schedule a cleaning of the screen at some future convenient time.

a few guys i know that are experienced with engines have been of the opinion that it is not a bearing, mostly because of the oil pressure. ill start working tonite, but i will probably have some info by the middle of this week.

i ran the engine with the valve covers off during the saga of smokeing, and if it makes any difference, i noticed that one of the pushrods was not spinning like the others. it seemed to be sticky. it was making half revolutions and quarter revolutions, unlike the others that were spinning away.

just did some diagnostics, and here are the results..


the number one intake valve is definately the source of the noise. it does not appear to be a lifter. the noise is coming as the valve closes, rather than when it opens. if cranked without the coil wire on, and you use a screwdriver as a stethescope, you can definately tell.