Packard Forum Index » V-8 (1955-56)

I just finished the oil pump change/conversion on my brothers 56 Packard 400. We purchased the kit and olds pump from Jack Vines, I followed the instructions from Jack and the pan removal instruction from the manual. I had to remove a few more things that the manual stated in order to drop the pan. Once I had everything down and clean it went along pretty easy. I used Jacks advice to replace the pan by making a couple of studs for the front two pan bolts in order to install the front cork pan gaskets. We formed the pan gasket to make it easier to install the pan without moving it to insure that it was in correctly, we applied the cork gasket to the engine(a grove on the engine, which allows you to seat the gasket first and then install the pan over the two studs), The rest was just put things back on in the reverse order you took them off. I used 10-30w oil and the oil pressure is at about 20psi at idle and then increase to 60psi as you increase the engine speed. So far all seems great, no more lifter noise too!
Once again Thank You to Jack Vines for the oil pump kit.

Good to hear. The Olds pump conversion seems to have solved a lot of issues and so far seems to be the most successful of all the cures tried over the years to "fix" the various V8 oil pump issues.

It is thanks to Eric (turbopackman), the late Craig Hendrickson, and KevinAZ for doing the initial pump research to find a pump that would work without major changes and then designing and installing the initial conversion pieces on Kevin's engine. Jack then took over the project and had the kit pieces professionally machined with some changes needed to turn their first of a kind work into the professional easy to install kit it is today.

Did you get the regular or hi volume pump and any sign of leaks at the rear main seal. To my knowledge the only issues are with the few engines which have developed a seal leak with the high volume pump.

We got the regular Olds pump. I have run it a few times but haven't driven it as yet. I did notice it has a left front wheel cyl that is leaking. I should probably fix that before any driving.

I just got the wheel cyl fixed and re-adjusted the throttle linkage. It seems to run and shift a lot better now. I took out my manual oil pressure gauge and put the repro oil pressure sender in and it worked for one test drive and then quit working. I think I'm going to look for a NOS sender with the hopes that it will work for good! Does anyone have a suggestion of who might have one?

Thanks, Ernie

Looks like Max Merritt does. 439867

https://www.parts123.com/parts123/yb.dll?userwatch~dynamicSearchPage~cadeffdE

When you say repro sender, what are you using and where did it come from. If you are using the Napa Echlin brand OP6091 senders, those are a standard aftermarket sender and also used on other cars of the 50-60s era, mostly Ford products since many models used gauges with the same electrical needs. The senders should not be failing unless there is something else going on and if that is the case, I would wonder how long a NOS sender would last.

One concern I always have with anything that old and NOS is deterioration. On the oil sender, no idea how the oil is confined or pressure is transmitted to the components inside to change the electrical output but that is something to consider. If it is a metal diaphragm or maybe a Bourdon tube arrangement then no worries other than possible oxidation on wipers or contacts. If it is a rubber diaphragm that separates the oil and flexes to work the electrical components then I would wonder how long the old rubber would stand up.

The oil pressure sending units I have purchased from NAPA(3 times). That is why I was thinking NOS might be better. My next question would be, does it make a differnce if I mount the unit in a way to make it easier to change them(see attached photo), does that alter how the sender reads the pressure?

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  Packard oil pressure sending unit.jpg (53.31 KB)

Verify the sender is for use with gauges and not idiot lights. Some senders look much alike but idiot lights only use an on/off switch while gauges need a resistance change. The Napa website used to give some specific pressure resistance readings with a given sender but Napa has changed their site and eliminated all that good info to the point it is almost worthless today. The proper sender will have a range of approximately 70 ohms at the 0 pressure end will move to about 10 ohms at 100 psi. Won't be easy to measure the high end but maybe place a meter between the terminal and base fitting to see if it reads somewhere around 70 ohms just sitting.

For a correct pressure reading the sender can be mounted at any point in the oil system that direct pressure out from the pump can be measured. As far as I know there is no restriction on how the sender is positioned when mounted. What the senders do need is an excellent ground. Believe I see some Teflon tape on the extension nipple. Possibly the tape is affecting the sender ground to the point it is not able to produce a decent resistance reading to the gauge.

As a temporary check to rule out a ground issue bare a few inches of 16ga jumper wire and wrap a few turns around the threaded metal port at the sender base. Be sure it is directly on the sender and not any of the extra piping. Attach the other end to a known good ground. If the gauge works reliably then do something with the tape on the extension pieces.

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Howard's description is, as always, spot-on but as far as your extra plumbing goes, I would advise against it due to the possibility that the small lines and no flow through them could get a trapped air bubble that might affect the reading.

If I remember correctly I did buy the unit that was spec for the gauge not the idiot light. I didn't use any tape, I believe you are seeing the shine of the new threads on the pipe. I'll try the ground wire thing first and if that doesn't work I'll reinstall without the pipe extensions. It just difficult to tighten it so it won't leak.
Thanks for the info and advice.