Two stroke diesel??

[northcreek2624]

Seems that I saw/heard of a two stroke diesel engine but,can't seem to remember the details.
Is there such an animal? and what would the application be?
Just wondering....Mike

 

[DK35vince]

Yes Mike,
There are 2 stroke diesels.
The old Detroit diesel engines were 2 stroke.,used in large trucks,bus,high lifts,rollers,etc.
Detroit has since gone to 4 stroke diesel engines.

 

[Hydraman]

Yep--there is such an animal!! The old GMC's were all 2-strokers. These weren't quite like 2'st. gas engines in that they had a pressure lubrication system, and oil in the crankcase just like a 4-st. But for the induction system they then used a supercharger to pressureize the intake. If you remember not too many years ago all the Grayhounds and Trailways busses had a noisy smoking gutless engine called a Detroit?? Detroit is what the old GMC became. The application were generally OTR trucks, truck mounted cranes, oilfield, and industrial uses. There were farmers that took the old LA model Case tractors(gas burner@ 50 hp.) and put in 3 cyl
GM's @ about 95 hp. Then about a year later they would all have to buy hearing-aids!!!! There were also some GM's put in some Oliver tractors- Don't know if this was factory or homespun, though.

 

[Darren]

You've been around lots of them. In vehicular applications especially they had a sound unlike other diesels. Imagine the sound of the offspring of a diesel bred to a vacuum cleaner and you'll be close. They're also found in a lot of stationary applications like saw mills and water pumps.

If I recall correctly they also had a reputation for oil leaks. If you want one, they're common as dirt. Before Penske bought the company they were built by GM.

 

[patrickg]

Sure an beggorah, lad, there be two stroke diesels. Back in the 50's while just a tot a friend of mine had a 2 stroke diesel model aircraft engine (not that rare). Funny thing, "regular" model aircraft engines are two stroke with glow plugs (sounds almost diesel, huh?) with some 4 stroke engines with spark plugs in the large economy sizes. The itsy bitsy diesel engines for flying models had variable compression. Where yo would expect to find a spark or glow plug there was a wingnut affair that you screwed in to raise compression and out to lower it. Lots of ether in the model diesel fuel as I recall. Buggers to start in the winter time, well heck, all the time but even worse in the winter.

There were several marine (vessel propulsion) applications of 2 stroke diesels. Little two stroke diesel engines were used in some foreign made powered bikes (Moped like things). There was a 2 stroke diesel imported into the us in the mid to late 50's (if memory serves) for retrofitting to a regular bicycle. Powered the rear wheel with a friction coupled rubber roller. No tranny, no clutch. Pedal to start. Braking to a stop killed the engine. Could disengage the rubber roller and treat as reqular bike. You pedal to start and to accelerate and to climb hills. It was not very powerful.

I think there were some diesel submarines with two stroke engines too.

Patrick

 

[MossRoad]

Here's a good article on deisels in boats. It explains the differences between the 2 stroke Detroit and the 4 strokers.

I operated a Detroit Deisel 6-71 in a ground power unit at the local airport for years. Man, when you put the power on, that thing would blow your ears off! The 6-71 is an awsome engine that will last forever with a little care.

<A target="_blank" HREF=http://www.yachtsurvey.com/comparing_diesel_types.htm>http://www.yachtsurvey.com/comparing_diesel_types.htm</A>

 

[bgott]

The diesel sub I toured had opposed piston Fairbanks-Morse diesels in it. There are some weird diesel engines out there.

 

[bgott]

http://www.howstuffworks.com/diesel-two-stroke.htm

 

[bgott]

http://members.shaw.ca/diesel-duck/machinery_page/diesel_engine/diesel_engine.01.htm

This site has some pictures of some big two strokes.

 

[Egon]

I beleive they were refered to as " Screaming Jimmy's "

My previous place of employment had natural gas Cooper Bessemer two cycle gas compressors. These things were at least 50 years old and had esentially ran 24 hours a day since new. They were a V10 design. Had a catwalk along each cylinder bank. The commpressor heads were an integral part of the engine. Max RPM was 300. They were air started and if backfired made a rather loud noise that dew the attention of a nearby town.

Egon

 

[hazmat]

A couple of the old Seagrave fire trucks I used to drive when I volunteered in college were two stroke detriots. Didn't have to use the siren much as the roar of the engine usually alerted others to your presence.

 

[em14]

I don't how to describe how noisey one these things (Detroit Diesel) was in large earth movers ... with a 6-71 blower screaming it was wild ... They were simple and relativety easy to work on ...

 

[patrickg]

bgott,
I don't know how detailed your tour was but did they mention that the clyinders on submarine diesels are typically not "square" with, i.e. alligned radially to the rotation of the crankshaft like say for instance a Cummins or Ford PowerJoke? They are slightly inclined, in the plane of rotation, to reduce "piston slap". This seriously reduces their acoustic signature.

I was only on two diesel boats, one was on static display in Hawaii (WW II relic) and the other is a Navy research submarine, hull number 555, the Dolphin (recently in the news because it was on fire) that was at the lab where I worked. The crew of the Dolphin sported "Diesel boats forever" on their T shirts. They do smell different from the nukes but the crew doesn't glow in the dark.

Patrick

 

[northcreek2624]

Fellow members, Thanks for sharing your knowlege with me.This is some good stuff and the sites are very informative too. Thanks for taking the time....Mike

 

[MossRoad]

It sounded like your were standing next to an air raid siren.

By the way, I've heard the term Jimmy several times around this engine. Who's Jimmy? /w3tcompact/icons/laugh.gif

 

[MJB]

I think the term "Jimmy" is a reference to GMC.

 

[Rubintropfen]

In fact, John Deere used a supercharged GMC 2-stroke diesel in the 1959 model 435 tractor. This was the last 2 cylinder tractor model that John Deere introduced.

 

[rjp444us]

There seems to be one 2 stroke missing from the list. Cummins built one in the early to mid 80s designated the 555 or better knowm as the triple nickle

 

[MJB]

There is also at least one more. Lanz made a tractor called the "Bulldog" that used a single cylinder two-stroke diesel. They had some kind of agreement with Deere to sell the tractors in this country quite a few years ago.

 

[bgott]

I was on the Blueback at OMSI in Portland Oregon. The guide didn't mention anything about the pistons. He had served on the boat when it was still commissioned as a supply clerk so he probably didn't know anything technical about propulsion. Funny you should mention the smell. According to him diesels were know as "pig boats". They vented the sewer gasses inside the boat because they didn't want a trail of bubbles. That must have been a very interesting place to live and work.

Another interesting Navy marine variant is an aluminum 6-71 Detroit Diesel engine. They used them in mine sweepers because a lot of the mines were magnetically activated and they didn't want to find the mines the hard way. Wooden boat, bronze or brass shaft and wheel, aluminum engines, I bet they didn't have much problem setting the deviation on the compass.