The Stovebolt Site Forums The Shop Area Engine Shop A Diesel in a 1954 GMC COE - any info

Question: GMC had a COE Diesel in 1954? Does anyone know much about the diesel engines in such a truck?
Pardon my lack of knowledge here! Seems most unusual. Thanks for any info. Mike.

4-71.

Ed

Detroit 4-71 2 stroke 4 cylinder with a mechanical blower, not a turbocharger- - - - -AKA "Screamin' Jimmy"! "When it quits leaking oil, pour some more in- - - -it's empty!"

Hy MikeStone1953, the largest of the GMC cabovers the "Cannonball" was powered by a 6-71 two stroke General Motors Diesel.

They were manufacture at Detroit diesel engine division in Redford MI west of Detroit.
In 1939 they produced the “71’’ family of 2,3,4 and 6 2 stroke engines. Each cylinder displaced 71 cubic inches. Bore x Stroke 4.25x5.00.
1939 4-71 had 110 HP@ 2000 rpm, 350 @ 1000-1200 Torque. In 1951 they had a “Million-Mile’’ upgrade that increase the HP to 150 @ 2100 rpm and 395 @ 1600 Torque. 54 they were Re-calibrated, HP 150 @ 2300 rpm and 374 at 1500-1600 Torque. In 1957 a one year only 4-71T turbocharged. 4-71 was discontinued after 1959.
1940 12 new Futurliners were built, replacing the original nine Streamliners. 10 used the 4-71.

Good info, Jimgmc -- keep going!

Ya, give us "the rest of the story", 6V, 8V, 12V. The 2 stroke Detroit is not what some folks think of when talking about 2 stroke engines. Unlike a 2 stroke weedwhip/chainsaw/leafblower where fuel and oil are premixed, the Detroit's have/had an oil sump, camshaft, valve in head design, similar to a 4 stroke engine and burned pure air and pure fuel. The main difference is that the 2 stroke Detroits were supercharged (blown) and the blower forced combustion air into the cylinder through ports in the cylinder wall. Each downstroke of the piston is a power stroke and each upstroke is an exhaust stroke. Intake air is through the port, exhaust is through the tulip valves in the head. The injectors are "unit injectors", no high pressure injection pump was used, the injector was mechanical and camshaft actuated, the high pressure was created inside the injector body with each stroke of the cam/injector. A low pressure transfer pump was used to pull fuel from the fuel tank, that pump was gear/shaft driven on the engine and supplied a continuous flow of cooling fuel to the injectors.

Great info coming in on this topic, but since it's mostly related to an engine topic, it's been moved to the Engine Shop as the best place to continue the learning.

Hy Guys, actually the 71 series Detroit Diesels went right down to a 1-71, the largest Detroit I've heard of in a truck was a 16V-71. The 71 series are a dry liner engine, that is, no engine coolant is in direct contact with the cylinder liner, the liners are removable and the block can be bored to accept oversize liners if the bores in the block become distorted. The later 92 series engine (92 cubic inches per cylinder) are a wet liner design engine. There was also the 53 series engines which found their way into trucks, they had higher rpm capabilities, 2800 rpm and in some cases even higher. As with most engines the two stroke design was refined and improved over the years, eventually computer fuel controls were added to the engine design and the engines torque rise was improved. Hope that helps

I'm pretty sure there was an aluminum block version of the 53 series engine, that was used in a piece of military equipment. Don't remember if it was a 4-53 or a 6V53. Much lighter weight and higher RPM than the cast iron types. The 1-71 was used to power refrigeration units on railroad freezer cars.
Jerry

The 6v53 was used in the M551 Sheridan light tank. I had an opportunity to drive one back in the mid ‘70s. It may have been an aluminum block because the whole vehicle was supposedly air droppable.

Al 6V-53 engines were used in small boats in Viet Nam extensively.

Ed

The turbocharged 350hp 8V-71 is the main reason I wear hearing aids today. The turbos were added to the 318 hp 8V-71 making it a 350 at the request of Consolidated Freightways as an aid to making better time over the Rockies from Cheyenne, Wyo. to Ogden Ut. At altitude, a 318 is a gutless wonder and at least one gypo trucker turned the governor up to 2800 so they would make a reasonable amount of power. This was not a secret.

The one I drove blew a gallon of oil all over the deck plate ever thousand miles. In winter with ice and oil all over the frame it was a dicey deal to climb up up on the frame to push the defrost button on the refer unit. In the 70s the 8V engines came with 2-piece pistons which no doubt contributed to the oil consumption. Not much power by today's standards but we were only grossing 80,000 except Wisconsin, which was 73,280 lbs. There was a sign in the drivers room that said, "Do NOT cross ANY Wisconsin scale loaded." I hauled 80,000 lb loads of fruit from Yakima, Washington to Appleton, Wisconsin on I-94, and US 10 in Wisc (no scales). Then drugstore sundries back to Seattle on I-80. A round a week. I was very glad to see that 350 engine come along. I had a whole afternoon free in Seattle after that.

The 350 solved the altitude problems but not the oil consumption and the 92-series was supposed to be a much better powerplant but by that time I had moved on to 350 and 400 hp Cummins-powered rigs.