Packard Forum Index » V-8 (1955-56)

I dropped the oil pan to replace a leaking rear main seal today, and figured on also installing the Olds pump. Took lots of pix to compare the two pumps. By appearances, the Olds pump likely flows more oil. However, there still is nothing wrong with the OEM pump that's been in this car for at least the 135,000 miles I've owned it. I looked it over to determine if it was a PI modified pump from yester-decade or something, but it is just plain old OEM.

Also removed the center main bearing cap to see how the bottom end is holding up since I rebuilt the engine around 75,000 miles ago. The center main is a good wear indicator, since it usually starts to go first. By the way this one looks, its good for at least another 150,000 miles! Its hardly even broken in. I have used Mobil '1', 15-50 since break in, and changed it religiously every 10,000 miles.

A disappointment though is the timing chain, which has way over an inch of slack. The shop manual says change it if over 1/2", so I will add that to the list. I wish someone would design a chain tensioner, so the chain would last as long as the bottom end. I may have to look into that if nobody else has any ideas.

For the leaking rear main seal, I will replace the rope style OEM witn a modern neoprene seal that fits misc GM and Jeep V6s. I installed one in our other 56GH around 15,000 miles ago, and so far so good. I also ran into a 56GH owner at the SB meet that says he installed one in his car and he's happy with it.

Soo many projects, so little time.

Joe H

Kanter sells, what i believe to be from pics, a double row ROLLER chain kit for the Packard V8. Keep us updated on your timing chain issue.

Looking forward to your inspection of the OEM pump.
1. Does the pump have an open pressure relief valve port???
2. Look CLOSELY at the cylindrical dowl that inserts into the rear main and inside of the dowl to see if there is a bronze bushing.
3. I am amazed that there is no major wear at the shaft-to-pump contact area.
More details to look for later.

Feel free to call me anytime voice to voice if u need to discuss the Olds pump conversion. I'm available mostly 24/7. Packard56V8@wmconnect.com for phone number.

What region are u located???

Joe, could you please post the actual part number for the neoprene rear main seal? That way we can enter it in the Xref. Thanks.

I live 35 miles south of Louisville, KY in a town caled Radcliff, which is about five miles from Fort Knox. Feel free to visit anytime, but its best to call first so I can be sure to be home (502-457-8120).

As for the neoprene seal, I had already posted it in this site's interchange section.

I too am suprised by the OEM oil pump's condition. It is an early type with the relief valve held in place by a cotter pin; does not have a suction pipe, etc.

Though suprised by the oil pump, I am shocked by the main bearing. NI have torn down about a dozen, and rebuilt about half of them; never torn one down that showed this little wear.

Joe H

Thanks Joe, I should have looked there first.

Joe. Give us an update on the pump and engine.

I fired up the car today with the Olds pump installed. The oil pressure gage indicated 25-30 psi at cranking speed, idled at 60 psi, and 70 psi at 2500 rpm.

A few notes: the oil gage reads about 10 psi higher than actual; the engine has 15W50 oil, and only reached around 120 degrees before I shut it off.

However, under the same conditions with the OEM pump, this engine has always cranked at 0-10 psi, idled at 35-40, and ran at 50-60 psi on the road. So in other words, oil pressure across the board is at least 10 psi higher with the Olds (Melling HV) pump.

Also noteworthy, along with the pump I had also installed new lifters. Usually with new lifters, it takes Packard V8s a minute or two before they pump up and quiet down. This time there was never a tick from any of the lifters. They apparantly pumped up while cranking over. Though admittedly it cranked a bit due to having guestimated the timing in dropping the distributor back in.

All in all, I am happy with the Olds pump.

Joe H

Did u have to grind away part of the pump to get oil pan clearence???

Yes I did, and also had to put a dimple (from the inside out) in the corresponding area of the oil pan.

I wonder if an OEM Olds pump may be a little smaller. The Melling HV has more than enough volume, so if the OEM is a better fit, size-wise, it may be more suitable.

Also, I noticed the mod kit does not have a provision to make sure the pump does not shift on the mount bolts. If it shifts over .050", the driveshaft could rub hard enough against the hole in the main cap / block to cause meltdown or lockup.

The Packard pump has this provision thru the close fit of the snout of the pump that fits into the hole in the main cap, that the driveshaft goes thru. The Melling actually had a hole already drilled, and all a person would need to do would be drill & ream a dowell pin hole in the main cap to match once the pump is correctly aligned and the mount bolts tightened down. In retrospect I now wish I'd done that.

All in all, it is a great mod that is long overdue for te Packard V8. Glad Craig got it all figured out for us :)

Joe H