1951 Humber Lohmann 18cc Diesel Cycle-attachment Engine

Click here to view at The Online Bicycle Museum

The 18cc 2-stroke Lohmann engine was officially described as a ‘mixture compressing self-igniting two-cycle motor.’ It fixes under a bicycle’s pedal crank and operates the rear wheel by roller.
When it originally went on sale in Great Britain, the price was just under £25 10/- There’s neither carburettor nor ignition system. Instead the engine works on a variable compression ignition system, which is moderated by the twistgrips.
Inventor and designer Hermann Teegen (1899-1962) is the spiritual father of Lohmann engines. He designed several similar engines, 3 of which were patented. From one of these prototypes, over a period of 3 years, the current 18cc Lohmann engine was developed. It first appeared in 1950, and 51,000 were built by August 1954.

1951 Lohmann 18cc Diesel Cycle-attachment Engine
Type 500. Model 51.
New-old-stock. Fitted to a 1935 Humber Roadster

I bought this Lohmann diesel engine in Europe. It came from a closed-down cycle shop, where it had been on a shelf since it was new. We fitted it to a 1935 Humber Roadster. It has good compression. Add paraffin and pedal away…








2 responses to “1951 Humber Lohmann 18cc Diesel Cycle-attachment Engine”

  1. Kurt Gubrud Avatar

    Ingenious design,low center of gravity etc.Is there a data sheet on specs.torque curves top speed @ rpm BHP tire wear . Decibel reading at full throttle.Could a fat guy ride up a hill without pedaling,did it smoke much?Total weight?

  2. Cynthia S Teears Avatar

    Curious if there is still anyway to find out where a Dunelt Bike was made using the serial number? 4168265

Leave a Reply

Your email address will not be published. Required fields are marked *