Sunday, January 31, 2010

Mystery Engine: "The Racer That Captivated Hitler!"

When Cycle Guide magazine closed in 1987, I had no idea where I’d be working next, or when, for that matter. I’d been a freelancer before CG, and figured I could be one again. So during my last days in the office I gathered up all the story notes and photos I’d been storing in my desk and took them home, hoping there’d be something there I could turn into a buck later.

What you see here snuck in with the stuff I knew was mine, and has been sitting in a box since they locked the doors behind us 23 years ago.

It’s a two-stroke engine, what used to be called a “twingle,” I think, with two pistons, one on a con rod and the other on a separate rod that pivots on the first one.

The big piston at the back of the crankcase has two connecting rods, both drilled for lightness. My guess is this is some sort of crankcase pump to help push the air/fuel mixture up into the cylinders, like a crude supercharger.

I found this photo this evening in an unmarked folder along with a large-format black-and-white negative and three photocopies, two of hand-written text, and the third a very bad reproduction of a man sitting on an unidentified motorcycle.

The first of the two pages of text reads as follows:

1935 D.K.W.

Deutsche Kraftwagen Werke

Zschopau, Germany

The racer that captivated Hitler!

The second says:

German Road Racer
3 cylinder, 2 stroke supercharged

Used at Isle of Man and other Grand Prix events

This particular motorcycle was found in Rodashia, Africa abandoned by the German Racing Team at the start of World War II.

The motorcycle was raced at the Isle of Man and a more refined version won the Isle of Man in 1938 in the 250cc class.

The motor has 4 connecting rods, 3 pistons, 2 firing cylinders and 1 spark plug. It is water cooled and was the loudest motorcycle ever to race the Isle of Man. When raced it got 14 miles a gallon.

That’s all I know about this engine, but I'm sure there's much more to the story, especially the part about how it came to be abandoned in what I assume to be, despite the spelling, Rhodesia, South Africa. The folder the photo was in wasn't marked, so I don’t even know where it came from, or who sent it to Cycle Guide in the first place, or when.

If you can shed any light on the matter, I’d love to hear from you, either in the comments section or via email at treadlifeblog at yahoo dot com.

Update: Information about the Mystery Engine has been flooding into the spacious Tread Life offices. Here’s the latest.

From Paul d’Orleans, whose wonderful Vintagent blog is a wealth of information about old motorcycles:

Hi Jerry,

The 'Ladepumpe' was used extensively by DKW for its racers, pre and postwar. It is a method of positively charging the cylinder in the two-stroke engine, with less power loss than a conventional supercharger. That's the big piston at the front of the engine. These machines were incredibly fast, and incredibly noisy! I have ridden with one on the track at Hockenheim (I was on a Velo MkVIII KTT), and behind a DKW is not where one wants to be! So I passed him... that was actually a really fun ride.

Hope this helps.

all the best, Paul

My friend Larry Parmenter, whose most recent blog can be seen here, put the question of the engine’s identity to a few friends, and got the following responses. The first is from Dennis Guggemos:

I've heard of that thing. The 3rd piston was sort of a supercharger, compressing the crankcase mixture before it got ported to the combustion chamber(s). The 3rd piston did not fire or deliver a power stroke. Just as Smith says. Gawd that piston is HUGE.

A twingle was a parallel twin 2 stroke with one common combustion chamber. Not sure this qualifies. It might be a "split single". I've seen arguments on the W650 forum about what makes a twingle or a split single.

Check this out

"...Marcellino's design had the pistons one behind the other,.."

That url also makes reference to a twingle as a variation of the split single, but this argument may just be down to semantics, or just when the word twingle came about, and it's the same as "split single".

Note the 1 conrod, Y shape in this configuration (link)

You can see how people would argue what a twingle was these different designs. Anyway still googling around trying to get some idea of what that 1938 TT lightweight TT winner was. So far, a split single designed by Ing Zoller... (link)

scroll down a screen or 2 to the green bike with #plate 36. Can't say this looks like the pic on Smith's page. But the description of the engine is very similar. This is the "loudest motorcycle ever to race the Isle of Man". Smith's photo is of the 1935 earlier design. Don't know what's different about them.

Another of Larry’s friends, Paul Duchene, said:

... I used to have a Puch 175cc twingle. Puch actually made a 4-cylinder racing version in about 1938 supercharged version I've seen in action at the Isle of Man. At the time, it was said the only thing more painful than the noise was the mileage. I can vouch for former...amazing. The problem with mine was the automatic oil pump which was very careful to supply enough oil to prevent seizure. The net result was that at 65mph on the freeway, I looked like an ME 109 going down in flames in the Battle of Britain... Still, people followed at a respectful distance.


Anonymous said...

"and was the loudest motorcycle ever to race the Isle of Man"

Is that one of the race categories? ;-)

Michael said...

Holy cow, Jerry, that's a helluva piece of obscure two-stroke history.

BTW, it's me: Mike Gillies. Been a long time since we closed down CG. What a fun period to be neck-deep in bikes, eh?

Take care,

Jerry Smith said...

Hey, Mike, good to hear from you! Yes, that was a golden time, all right, with the keys to the candy store hanging on the office wall.

Have you checked out the Cycle Guide Magazine blog Dain Gingerelli and I are doing now?

Drop us a line at

donald said...

Hi Jerry!
In search for some pictures of the Ladepumpe 250 DKW I stumbled over your blog. In our workshop in the Netherlands we are rebuilding the 1937 Ladepumpe that originally belonged to Karl Lottes, a german private driver with racingnumber 104. At the moment we´ve finished the paintjob except from the fuel tank. It must be recoated from the inside and after that we will paint it twotone. Grey and green. The large piston is missing just like the two rods; it was secured in place with a large bolt during running times. Back then they were asked friendly NOT to use the Ladepumpe because it made a hell of a noise. Now the piston must be recasted and the rods must be machined. Luckily we have original drawings! When you are interested I can send some pics of the restoration! Greetz, Donald