Inliners International Forums General Discussion Truck Talk I just bought a 46 Maple Leaf

I just bought a 46 Maple Leaf, (Canadian GMC) with a 270 engine, now for the questions, did they produce a 270 in 1946 and are they a pressurized oiling system or a splash system?

Congrats on the new acquisition. What are your plans for it?

AFAIK the 270 was first shipped in '46. What's the casting number on the block?

Congrats! Need some pics!

According to this wikipedia page, it was produced from '41-'63.

https://en.wikipedia.org/wiki/Chevrolet_straight-6_engine

I believe it will be splash, not pressurized oiling, unless it's a more recent engine from the mid-late '50s. Dollars to doughnuts it's most likely splash.

Is that on a 1-1/2 ton dually? If it's in a 1/2 ton it's definitely replaced, but that would be a hoot!

None of those engines are "splash only", that refers exclusively to the rod bearings. All main bearings are pressure oiled.
All G.M.C. engines have full pressure.

panic,

I thought the lubricated lifters referred to that.

Were the main bearings always pressure oiled?

Jim Carter noted a difference in the newer blocks from '53 forward, that they have modern insert bearing rods which are like modern engines today. I don't think that would effect the lubrication at all though, would it?

Good point on the oiling, I'm not a real wrench, just play one on the Internet. When I think of splash oiling I think of the type of oiling where the gears sling it up over the top of everything, like a metalworking lathe. I don't think trucks are like that though. I guess I should STFU while I'm ahead.

It's a 3ton that was shortened up so it would fit on a car trailer., I'm thinking about locating a 10-46 Chev/GMC pickup be and installing it for a dually pickup. https://photos.app.goo.gl/UD4EKZELFPCYDRCV7

The body looks pretty good in that pic.

FYI, you can take the body and put it on an S10 frame, and the body/cab is the same as the 1/2 ton I'm told. That will give you another option.

The fenders will not match up, but you can get fenders from a 1/2 ton, or just center the existing ones up. The big truck fenders can look cool when they are lowered a tad.

I was looking at doing that with a '46 1-1/2 ton that was in running condition, but found this 1/2 ton I have along the way...and I never got the flatbed. It had the extra lights along the top of the cab, spot light, and some other goodies.

Do you have the headlight buckets? They go for some coin...

Jim Carter noted a difference in the newer blocks

Those are Chevrolet engines.

Though the Chevy and GMC sixes have many similarities and even some part interchange they are different engines. All of the GMC overhead sixes were pressure to mains and rods. 228-302 pressure oiled.

You guys taught me something there, I didn't realize. So in a sense the GMC engines were better than the Chevys in that regard, at a premium, as I think they charged more for GMC.

The one thing I've been curious of, maybe one of you know, why were the GMCs positive ground?

I have often wondered that myself. Several brands were positive ground through the '50s. In the beginning GMC used Pontiac and Olds flathead sixes. I don't know if those two were positive ground and it just carried over.

There's a nice write up here at MGA Gurus about the two different conventions and why things eventually converged on negative grounding.

The next thing (in my own order of importance) is which head does your 270 have? There are 4 different castings with different port sizes, and combustion chamber shapes with pistons to match, not all made the same year.

That's a good explanation, thanks for posting that link.

That with your description of the alternator having the ability to switch off when fully charged, make all of that part make sense to me. In a way an ammeter is kind of a geeky thing, to know exactly what is flowing through the wires. Where with a voltmeter you would see constant voltage on the circuit. Hmmm...Most modern vehicles don't seem to have either ammeters or voltmeters...AFAIK.