[2manyT/A'S]

Was Pontiac's straight 8 (post war) a full pressure oiling system....with oil pump and filter?

[U47]

Yes, a full pressure system ( 1933-1954) with all bearing inserts. No external oil filter. A filtering patented system oil screen which is meant to be cleaned after a engine rebuild. Or about 100,000 miles. This filter was about a cup in size until 1941, then it was made larger and held about a quart of oil. Some people and dealers installed what is known as a bypass oil filter, but the factory said the engine didn't need it.

[2manyT/A'S]

Thanks for posting...
Just curious...
Was that a sludge trap....in the pan?

[U47]

I guess you could call it a sludge trap, but it does more than that. I wish I could find some images of it. Apparently it worked pretty good. There was a very good article of it and diagrams in Hemmings Classic Car Magazine a few years back.

[2manyT/A'S]

I need to look through my magazine stack..

Is there any internet sites...for the 40's and 50's (pre-V8) Pontiacs.....?

.All I can find is Chevrolet..

[U47]

I'd like to tell you what issue it is in, but it's got to be about five years back. If I was in my shops library right now I would have a go at finding it. It would be a search though. There was also a article in POCI Smoke Signals way back, but that club really doesn't feature flatheads that much.
I tried to find a image on google but that was no good. There is some talk but no images. The darn thing kind of looks like a slightly smaller British WW2 land mine. Bout 5-6" dia. and about 3" thick.

[jmt455]

The "Early TImes Chapter" of POCI is focused on 1926-54 Pontiacs.
LOTS of knowledge and helpful folks in that group.
Here's a link to the chapter website:
http://www.earlytimeschapter.org/index.html

[U47]

Originally Posted by jmt455

The "Early TImes Chapter" of POCI is focused on 1926-54 Pontiacs.
LOTS of knowledge and helpful folks in that group.
Here's a link to the chapter website:
http://www.earlytimeschapter.org/index.html

The problem is their web site does not give any detailed information on this unique oil filtration system.

[jmt455]

Originally Posted by U47

The problem is their web site does not give any detailed information on this unique oil filtration system.

Yep, good point.
It's a good place to find contacts but not much of a technical resource.

There are only two references to oil "filtration" in the 1933 Chassis Service Manual.
Here are pics of those 2 pages.

The first reference is in the Oil Pan Assembly section:


And this, from the Engine Lubrication section.
The left column describes the oil pump and filter/screen function:



"Oil pressure may read zero with the engine idling but should show pressure with the throttle open slightly."


I have not touched the straight 8 in my 33 yet, so I can't offer any hands-on info.

[U47]

In 1941 the filter was redesigned.

[fyrffytr1]

I can't remember where I saw it but according to the 50 Pontiac service manual there are only two instances in which the oil screen is cleaned. One is of the engine is removed for rebuilding and the other is if the vehicle is involved in a roll over accident. You can't say that for a modern car. If I find that reference I will post it here.

[U47]

Never heard about the rollover, but the filtration screen assy. is meant to go for the life of the engine.

[Jack Gifford]

Interesting stuff in the '33 manual.
30 head bolts!
Zero oil pressure at idle is normal!

[mgarblik]

Yea, oil pressure is overrated, you just need to keep the parts wet!. I do like the 30 head bolts to seal that huge cast iron lid over that 6:1 compression engine. Modern engineers could learn something from from the obvious over design and built to really last philosophy of these old engines. Modern engines are so flimsy, if torque to yield fasteners, and exact methods aren't used, the whole thing warps, bends, cracks, and falls apart like a cheap piece of origami.

[U47]

By 1950 the High compression head was up to 7.5 to one.

[ClassicDriverMan]

In case anyone is curious what the "oil cleaner" actually looks like.. see pics.

I am doing some general clean up of my straight 8 out of my 51. Pulled the motor and replacing the blown exhaust gasket and decided to pull the pan and clean the "cleaner:. The motor was rebuilt according to the previous owner, but I have no idea how long ago. Looks real nice inside. I suspect it was little used. There was about an 1/4" on slug in the cleaner... so I guess it works!

[U47]

Originally Posted by ClassicDriverMan

In case anyone is curious what the "oil cleaner" actually looks like.. see pics.

I am doing some general clean up of my straight 8 out of my 51. Pulled the motor and replacing the blown exhaust gasket and decided to pull the pan and clean the "cleaner:. The motor was rebuilt according to the previous owner, but I have no idea how long ago. Looks real nice inside. I suspect it was little used. There was about an 1/4" on slug in the cleaner... so I guess it works!

Thanks for posting. I looked everywhere for some pictures.

[U47]

I was in the middle of watching a video on the rebuilding of a Packard V-12 and the oil pick up and screen and baffle assy. look very much like Pontiac.