Packard Forum Index » V-8 (1955-56)

I finally got around to it and pulled my distributor out of the 56 Pat. The vacuum unit works and advances the breaker per the specs in the manual, but, it does not hold the vacuum and begins to leak down right away. Are the delco remy units still available and if so where. My local NAPA guy says he has one that should work but is not a DR unit.
#2 Is there a way to test the centifigal advance off the car without the distributor testing machine. I know the centrifigal advance works but I don't know if it's working per specs in the manual.

#3 ? What is best choice to lubricate the breaker plate. I read on another site that a siicone base is best, but,I have noticed that silicone based lubricants tend to become sticky and seem to lose it's slippery properties after not too long a period, which seems to rule it out for such use.

One can check the mechanical or automatic advance without a distributor testing machine with the distributor in the car. It is a tedious job but with the vacuum advance disconnected and line plugged, check the amount of advance on the vibration damper timing marks at different engine speeds (500, 1,000, 1,500, etc). Note the amount of advance at each speed and compare it to the specifications. It is probably okay.

I believe the main difference in the same type of vacuum advance units is the spring and shims (if any) in the units. You may be able to use a unit from another distributor (same manufacturer) by using your spring and shims (if any).

I have used a light machine oil for lubricating the breaker plate with good results. A little goes a long way. Lubricate the felt pad under the rotor with a couple of drops of this oil too. Some light grease like Lubriplate on the cam lobe is recommended. Again, just a small amount spread on the lobes.

Clean the distributor thoroughly while you have it out of the car. It is a cinch to install new points and condenser at this time too.

Let us know how you come out on this job, and good luck.

While we're at it, has anyone determined the total of how many distinct variants of specifications there were of the two types of distributor, Delco and Autolite?

1. Why a low-volume manufacturer such as Packard chose two different makes of distributors, two of 4-bbl carburetors, starters, generators boggles the mind!

2. The engineers went to a great deal of trouble to test and specify different vacuum and centrifugal advance curves for different horsepower and load applications. Too many owners/mechanics think because all the distributors physically drop in, they are interchangeable. Not so!

3. Because a vacuum advance unit can be made to fit a distributor, it may not be the optimum for the engine and car. The only way to do it right is off the car and on a machine. Yes, with great effort an approximation can be done on the car, per JW.

4. The proper centrifugal advance, vacuum advance and initial advance settings are crucial. The Packard is a high compression engine and running on the edge of pinging with today's crap fuels. If the ignition is not as it should be, damage much greater than the cost of a pro distributor rebuild can occur. I've seen pistons which look as if they were attacked with a tiny ball-pein hammer. That pinging which you hear or don't hear is a physical blow ringing through the walls of the engine.

5. Too many Packard owners cheap out and use regular 87-octane, "Because I don't drive it that hard." False economy if there ever was one. No fuels commonly available at the pump today are of sufficiently high octane for the Packard V8, but the 91+ are the least bad.

thnx, jack vines

JW, Thanks for the quick input.
My intent was to remove the breaker plate and the centrifigal advance and clean everything, spray paint the outside housing, reassemble using new point set, condenser,rotor and cap, but to me the instructions in the manual seemed to be short on the how to information. I got to the task of removing the breaker plate but, when it mentioned a spring at the side of the plate (which I suppose is under the plate) I chickened out, fear of breaking something. I'll get my nerve back and procede but what is so critical about removing the breaker plate, looks like just one spring screw holds it in?

Jack Vines,
There are no Pro shops around here to do that type of work. And I have had some very bad pro mechanics work on some of my cars and motorcycles in the past years. In 1977 I had a very respected speed shop that did a lot of engine builds for the old nascar drivers rework the heads,change the cam and exhaust, to improve the torque of the 390 V8 I used for towing my trailer. The engine blew up within 100 miles. I have had lots of similar experiences with lots of other mechanical work. So if I can figure out how to do it and do it right, I'd rather spend the time and money doing it myself. Besides it is even harder to find a decent mechanic today than it was in 1976. Today most of them don't know and don't care.

If you can DIY, then absolutely go for it. If you are certain your distributor is the original, then you can DIY - the disassembly/reassembly is not difficult. If proper care is used, nothing should be broken. Do the work on a large sheet of clean, white paper. There are a couple of tiny C-clips, hairpin springs and screws which are easy to lose.

Setting the point gap is much easier to do on the bench than in the car.

Checking centrifugal advance is possible on the car, as per JW. Confirming the vacuum advance curve requires a tool, such as the Mity-Vac, about $30-40 used. However, since vacuum advance is not readily adjustable and OEM vacuum canisters are NLA, as long as it holds a vacuum, what you've got is what you've got.

Good luck.

thnx, jack vines

Jack, Bowman said that the advance chamber does not hold vacuum. I recommended he find a unit and use his spring and shims. What do you think about this?

Jack said"1. Why a low-volume manufacturer such as Packard chose two different makes of distributors, two of 4-bbl carburetors, starters, generators boggles the mind!

I believe Packard did so to keep their supply lines open. They had to shut down for a week one time because Bendix had a strike. So they used two different suppliers for many things including radiators, tires etc.

Jack Vines, The Distributor is OEM Packard per STB 56T-14, when they went to the Delco p/n 6489847 (Delco 1110880) to correct a reported problem of detonation due to poor quality of gasoline being suppplied at that time. The vacuum unit is also OEM. But one thing I noticed when I pulled it out of the engine, there was no gasket on the shaft or hole in the block. The manual idicates there should be gasket there, which means the distributor was removed previuosly for some reason.
I did test the distributor on the car using engine vac, timing light and dwell/tach meter. The cap, point set were all in great shape, although the gap was too wide @.019, rather than .016.
At 500 RPM (the lowest the engine would idle) the dwell was 26 degress with the timing set @ 10 degrees BTDC, (spec requires 26 to 33 degrees), I also checked the centrifigal advance and it worked when engine speed was increased. I did not do extensive testing and did not record any of the readings because I had decided to pull the distributor but first I wanted to know if everything was working. I also checked the ignition coil, plug wires, plugs, engine vacuum and compression. All tested okay and within specs.
I also made a trip to NAPA and was told theyy do not have a Delco vacuum unit and have no way to cross reference the Packard or Delco p/n's to another vendor for a replacement.

Vacuum advances from most any early 50's 8 cyl Delco distributor will bolt right on, but to maintain the proper advance curve you must use your old spring and shims. Even the 53-4 Packard advances can be used, as if they were easier to come by. I have used Stude, for sure, and Olds and possibly Caddy. I pick them up at flea markets whenever I see them. Once they have started to leak, death is imminent, so don't even bother to put a leaky one back on.

Ross, Thanks for info. I was thinking pretty much what you just said and have been checking the web on the forums for 1950-ish Gm and Stude threads on distributors and timing issues to try and get a delco part number or alternate vendor but, nothing yet. I have also tried all the locals such as NAPA, Autozone, advance and carquest but even if the part is available the slugs working there couldn't find the part. If you don't have the exact part number it is pretty much useless to go there. But, I still go and try it anyway. I have also tried the Delco site but no luck. I will find one or alternative and when I do I'll pass it on in this forum.
THNX Again,