The Stovebolt Site Forums The Shop Area Engine Shop Heavy Duty 235? Fact or fiction?

On another post it was mentioned that Heavy Duty 235 motors were made, and painted green.
In the operators manual for 1948 under "Valve Tappet Adjustment" it lists clearance for "Normal operation" and "Heavy Duty Operation".
In the Valve Adjustment article in the Tech Tips it specifies 1.5 ton trucks exhaust be set at .020' as opposed to the standard .013-.015'.
So my question is; was there a Heavy Duty engine that is different then a standard 235? Should I set my valves to the "normal" or Heavy Duty" operation clearances? Or is that 100% dependent upon the intended use of the vehicle, or is it because of different engine components being used? What are you setting your clearances too?
Here is my engine information:
The engine casting code is 3693374 (1942-49 235ci)
Engine Block date casting code #con 4 A 228 (01/22/48)

I'm just guessing that the normal vs. heavy duty difference in a given year is aimed at the truck's use and not any mechanical differences. But I'm just guessing.

They did build splash oiling 235's before the full pressure version, but in a given year, it just might be how the truck would be used.

I may be wrong, but I think the only difference is the intended use, I.E. Heavy loads, like if the engine is installed in a bus or something like that. The more load it is under the hotter the components will get. (not neccessarily the water temp, unless of course you exceed the cooling capacity of the cooling system)

Yes, the Loadmaster 235 was the only truck 235 in 1948 (the COE had a slightly different 235, due to the updraft carburetor). The Loadmaster 235 would have been referred-to as the heavy-duty engine.

If you are running the engine at high revs for long periods, use the "heavy duty" valve settings.

Curt -

Here are some interesting differences between early 235's and full pressure 235's. Answers my confusion about seeing a "216" valve cover on your 235.

Thanks everyone for the responses. Now I am have a better understanding of my 235. Was the Loadmaster motor or any other 235 painted green?
Lonnie does my valve cover have incorrect nuts holding it down?

The correct valve cover nuts would be acorn nuts.

What year 235 Loadmaster?

Here is one person's list of engine colors. I think his list is one of the best compilations. However, some people disagree with his shades of gray.

You'll see at least one year in which a green 235 is listed.

The first 235s looked exactly like the 216,long side plate and two bolt valve cover.Every one in my area set the valves 8 and 16. The big trucks had aluminum timming gears.If you set them too loose you slow the valve timming thus loosing HP.

Long side plates on all low-pressure 235s(two-bolt valve-cover 235s)?

I think that 1950-1953 235s had short side covers?

Also, our Canadian friends might add information about short side covers on at least some 216s.

All US 235s starting in 1950 had the short side cover.

Some Canadian 216s for 1950 to 52 like mine, had the short side cover. The 235s had the same arrangement. The heads were different than the 1953 head and can be identified by the bulging contour between #1 and #2 spark plugs.

I said the FIRST 235s which came out in the 40s.I dont know anything about Canadian models.The oldest 235 I ran into was in a 1944 big truck,but I cant rule out an engine swap.

1941 was the first big truck 235 in the US.

I have always wondered if comming out with the 235 during the war had anything to do with govt. contracts.

Coming out with the 235 during the war?

Maybe GM/Roosevelt had the 235 introduced in 1941 so that it would be ready for the declaration of war at the end of the year in December?

Good thought

Your comment was a good comment. Just a few months off. A lot of those 235s were used during WWII. However, do you think the GMC engines were more highly regarded?