World's Largest Diesel Engine. 4 Stories tall.
 

Being pulled by a Mercedes diesel. https://www.thevintagenews.com/2016/01/08/45014/

I tried to order one up for Mutt the Race Truck but they were on backorder. Probably just as well as it would have put me in AA engine class.


(besides, it might crush the truck.....)

Dan

Why would a 2-stroke need valves?

What I got out of it was that the cylinder next to it added the atmosphere mix which causes the exhaust to be pushed out via the exhaust valve.

when i use to commercial fish,our boats had detroit 6-71 marine diesels.I liked them a dime was used to set the valves.The Abalone boat had 2 stroke diesels and would fly.our boats did 6 knots tops.I often wondered why cars never had high speed 2 stroke diesels.

Emissions mostly, the Detroit Diesel 92-series (~2100rpm) were pushed out of DD's highway engine lineup in the '90s due to emissions, and the efficiency of the new and proven 60-series 4-stroke engines.

Possibly ironically, from what I've read the 2-stroke engines are believed to be more efficient and with modern valve and injection controls, might be able to be developed to the point of meeting emissions today.

What I don't understand is why trucking continues to use large, heavy, low-rpm diesels to produce their power when there are plenty of much smaller high-horsepower engines that can produce as much (or more) power in a smaller package, have the durability, and will save a lot of weight and fuel.

Because they don't use the crankcase as a mixer/supercharger like a 2stroke gas engine does.
There are slats in the bottom of the cylinder walls, when the piston is at BDC the supercharger/turbo blows the exhaust out of the exhaust valve, the valve closes and the cylinder is pressurized. Then the piston moves up an does a typical compression/ignition. When the piston goes down the exhaust valve opes and the process of blowing out the exhaust, then charging the cylinder happens again.
This is the reason that detroit diesels need a supercharger to work.

Chris tree'd me. He's 'zakly right. A trick question at a gathering of Diesel fans - "How many HP does a Detroit 2-stroke make without a supercharger?" The answer is "zero" - They won't run. Most Diesel fans haven't messed with a DDA (Detroit Diesel Allison, the name of the company when they were making these) and so folks haven't any experience with them. We ran one on the dyno and it made a ton of lb/ft but was, as noted, VERY high in emissions.

Another Diesel trivia question though my info is a bit dated: Last I heard, Penske owned Detroit Diesel and was making them in MI. I did a tour of their emissions facility as we looked for a correlation offset between their lab and ours though I can't remember for the life of me what we finally determined.

Dan

If someone has not mentioned it Detroit Diesel Engines have Exhaust Valves. Detroit Diesels also use the (The engine is uniflow-scavenged by way of exhaust valves) Uniflow type scavenging.

When you get to large engines, you see many unusual combinations. Also, parts are so large that things like the crank may be constructed from multiple components. Decades ago, I designed controls for large stationary natural gas pumping engines. They ran on the natural gas from the pipeline, were 2 stroke, but had valves, plus ports in the cylinder walls. I vaguely recall the ports were for intake (after a compressor & throttle) and the valves for exhaust. Don't recall if the compressor was turbo or crank driven). Even the connecting rods were different, with one attaching to the crank and its V neighbor attaching to it above the crank. It was spark ignited, but was controlled more like a diesel by adjusting fuel flow, w/ the throttle usually wide-open. They can do this because natural gas has a much wider flammability limit than gasoline, so can still ignite when very lean.

BTW, people get confused in numbering V engine cylinders. They should be numbered front to back in the order they attach to the crank (recall Ford doesn't do so). But, in this engine the V cylinders were directly opposite each other.

Daimler owns Detroit Diesel, makes a range of engines DD(displacement) for trucks, the largest I believe is the DD16.

The picture in that article is only of a 7 cylinder bank, double it for the biggest 14 cylinder.

Interesting about diesel 2 strokes and valves. Detroit 2-51 and 4-51 engines have no valves, they have inlet and exhaust ports...loop scavanging as opposed to uniflow. Can also do loop scavenging with poppet valves only, many tinkerers have done that to even the OM617 with custom camshafts etc.

Imagine working on the ball bearings and Fetzer valves on that one! (see vid below:D)

https://www.youtube.com/watch?v=Hjsfs49SRbc

I've seen that like 20 times and it still never gets old.

In the 1930s the design was bought from Gray Marine.