Packard Forum Index » V-8 (1955-56)

PackardV8 wrote:
Quote:
<p>Name one that is NOT solved by the Olds oil pump. The only oil system deficiency (not oil delivery problem) that I think is significant is the bypass-style oil filter.</p>
<p>Craig</p>

I contend that hte valve guides starve for oil. Premature wear at the guides. The Olds conversion solves a great many lube problems with the engine as well as cost effectiveness and ease of service and longevity etc. But the valve guide issue is seperate.

I contend that hte valve guides starve for oil

I think you'll find and perhaps JV will respond in more detail that there is a very wide degree of variation in original V8 engine life, some going well beyond 100,000 miles with no problems, and others with problems very early on, perhaps at 40,000 miles of thereabouts. Some of this may be due to how dedicated dealers were in making changes like the several changes to rocker shaft oil holes, and just how well thought-out those changes were in the first place. And of course another variable is the care the engine received from the first and subsequent owners.

Quote:

Very true. However most of the engines we build do not come with mileage and maintenance history. That has been long lost. These are the constants we find:

1. Main bearing wear is the serious failure area. Most Packard V8s by now have had the crankshaft main journals reground at least once - sometimes ONLY the mains and not the rods. This suggests these were a dealer warranty repair and not a high mileage wear issue. We're still trying to determine the design flaw which causes this. It could be as simple as air in the oil.
2. Re-bores are rare. Few Packard V8s ran enough miles with the original owner and were worth so little used, so they were never completely rebuilt. The OEM pistons are not especially strong. EVERY standard shift '56 Studebaker Golden Hawk engine I have torn down, some pistons were cracked where the round skirt meets the flat strut reinforcement. Also, the OEM engine did not take kindly to high revs. Every one of the '56J standard shifts showed evidence of a piston replaced due to a dropped valve. Many sedan engines have collapsed piston skirts. When we are re-using OEM 374" pistons in a .125" overbored 352", we have to go through three or more 374" engines to make one set of eight good pistons. Surprisingly, one 374" engine had .003" oversize piston pins in STD bore pistons. We still don't know what that was all about.
3. Valve guide wear seems no worse than other engines of the era. The Packard V8 has long valve guides, large valve stems, geared for low RPMs, light valve spring pressure, gentle cam ramps; consequently valve stem wear is not the worst wear area overall.
4. Rocker arm tips show wear and have to be reground. If there is lifter clatter, there is also clearance between the rocker arm tip and the valve stem and this causes more wear.
5. Rocker-arm-to-shaft wear is an expensive area to address during a rebuild. I only know one rocker arm rebuilder who does re-bushing and it is $350. If the rest of the engine is tight, there will usually be enough oil pressure to go around.
6. Inside the rocker arm shafts are ALWAYS full of crud. The soft plugs in the ends of the shafts are a PITA to remove. We clean the shafts inside, but no one else ever seems to mention doing this necessary chore on a rebuild.
7. We have only ever seen one camshaft with a flat lobe. Most could be re-used as is, but we always regrind them for use with new lifters.
8. Valve seat recession is not usually present, as many Packards died before unleaded fuel. We always install hard exhaust seats.
9. FWIW, we don't have a problem with the OEM bypass oil filter. If the engine has been thoroughly cleaned during the rebuild and the oil is changed regularly, there will be no problems due to the oil filtration.

Just a few lessons learned from seeing the insides of many engines.

thnx, jack vines

" The soft plugs in the ends of the shafts are a PITA to remove. We clean the shafts inside, but no one else ever seems to mention doing this necessary chore on a rebuild.


I've cleaned 3hree pair of such Packard shafts and other makes withOUT removeing the end plugs. Enter a string at one end thru existing bolt hole 4our times longer than the shaft. Use air pressure to blow/suck it thru the other end. Tie a small swatch of cloth to centre of string and draw it backwards and forwards thru the shaft. It is a bit time consuming but relieves the headache of dealing with the end plugs. clean the ends with a ice pick or something bent over 90 degrees.

I can get them fastidiously clean using that methid.


It amazes me that u have not found any excessive guide wear to the tune of .004 to .006 OVER the high end of spec. ESPECIALY on the exh. guides. UNLESS most of your engines have the EARLY 55 rockers with pee holes.

Jack. Point #1 u indicate above mite be due to oil gallery diameter too small. I don't know. How does the Packard V8 oil gallery diameter compare to SBC's or other proven engines?????? I'll try to check and SBC tomorrow.

OR, maybe Packard skimped on the main bearing material???

The oil gallery feeding the mains intersects with the main longitudunal oil gallery feeding the lifters. Have u checked the end of the gallery directly where it enters the main longitudinal oil gallery to see if there is any drill burr or other restriction in that area???

That is to say, maybe the drill did not make it all the way thru, only the tip of the drill made it thru thus causing a restriction??

The interesting question about this is, how many recently rebuilt V8's have over 25,000 miles on them? That's usually when the problems begin to develop. I'm betting close to zero. Let me know how that rebuilt stock Packard pump works at 25,000 miles and up, I'm betting it won't fix anything at all, and the original problems will resurface in time.

OK guys, for what it's worth, here's my story. My 374 engine was rebuilt in 2005. It had about 93K miles on it and it had been rebuilt at least once before I bought it. When I have no idea. When I got it back from the shop (after we had moved four states away) it was running absolutely great! No lifter noise, no problems at all.

I drove it around town, on the interstate, trying not to be too hard on it but not babying it either. At about 1200 miles, as I was driving at about 55 mph, I started hearing valve train noise. I looked at the oil pressure gauge and it was at zero and the noise was getting louder very quickly. I pulled into a parking lot and turned her off and had her towed to an engine shop.

They dropped the oil pan and found the pump drive shaft had sheared off at the spline. This was a rebuilt pump that had been installed when I had it re-built. The shop didn't remember which of the two sources they use had supplied the pump so I won't speculate here.

The local shop rebuilt the engine and we got a rebuilt oil pump from Bob Aller. The shop noticed that it didn't fit right. It seems the drive shaft didn't line up correctly with the pump shaft and it was binding. We speculate that this caused the earlier pump shaft to shear. They machined the pump to fit and installed the pump. We found the pump was pumping air mixed with the oil (checked at the oil filter supply line). The engine had horrendous lifter noise. It sounded like it wanted to blow something out the top end. I sent it back to Bob who returned it saying there was nothing wrong with it.

That's when I contacted Craig about the Olds pump. The shop had to do some machining on the adapter to make it fit so we think there was a problem with the mount point in my engine. The Olds pump has been in the engine for two touring seasons now, has about 3500 miles on it, and I haven't heard any lifter noise, not once.

Well, that's my story. Maybe it wasn't the pump's fault that the shaft sheared. All I know is that it's running great now.

My 56 Pat has 41,000 (supposedly actual) miles on it so based on what I have been reading, I can expect it to disentegrate or require a major engine rebuild anyday now.
I'm sure it has some,most, or all of the factory mods talked about here, because it was built late in the 56 model year, but I don't know that for a fact because I haven't removed the oil pan,yet, but I intend to, just out of curiosity. My engine was quiet with no lifter noise at startup or after reaching normal temp. after setting for days,weeks and even months, until I had a timing issue recently, then I got lifter clatter some pinging, banging,etc, but only in the left bank, oil pressure was a steady 40# and oil pressure was good in both heads also. So I'm attributing all of the noise to timing issues and not oiling issues, at least for now.
Is there not such a thing as having too much oil pressure as well as not enough.

YES! This IS typical of the oil pump sucking air. Left side pronounced is typical because of the oil gallery configuration which was another PMCC F'up.