Old Ignition Engine

[Rick_Huff]

I found this old engine at a friends place the other day.  I brought to the field and asked a few of my flying buddies about it.  Nobody could identify it.  One of them had an old engine book and we couldn't find it in that either.  Anyone have any ideas?
Rick

[Tim Wescott]

I couldn't tell you what it is, but it looks pre-war.

[Dan Berry]

A source tells me that it might be a Madewell 46. A size reference would help my source.

[Dan Berry]

Now he's saying maybe it's a Wensen.
I might stop paying attention to him.

[Rick_Huff]

Dan,
Here's a photo with a scale. 
Thanks,
Rick

[Bill Mohrbacher]

This might be a home made engine.  Can you show a closeup of the spark plug?  Is there a manufacturer's name on the plug?  This may help.

[Rick_Huff]

Bill,
Here's a photo of the plug.  Looks like "ZK" on the plug. 
Thanks,
Rick

[De Hill]

Back when high schools had extensive shops for students,  (pre and a little after WW2) they would make their own engines, with varying degrees of success. Also, in the same time frame , the aircraft factories would allow employees to use company equipment during down times. The engines are usually called "Whatzits" because they usually resemble a well known engine, but have important visual differences.

The engine pictured in the above posts resembles a Ball, but it isn't one.

[rustler]

See if you can accurately check the screw threads. It may be European. Very interesting.

[Tim Wescott]

See if you can accurately check the screw threads. It may be European. Very interesting.

The head screws certainly have a British vibe to them -- mumble-mumble BA, if you ask me...

[Rick_Huff]

I took out one of the head bolts and it's not a thread I'm familiar with.  The OD is 0.114" and the pitch is ~51 tpi. 
Rick

[Tim Wescott]

I took out one of the head bolts and it's not a thread I'm familiar with.  The OD is 0.114" and the pitch is ~51 tpi. 
Rick

Hmmmm.  'taint BA then.  https://en.wikipedia.org/wiki/British_Association_screw_threads

Metric?  M3x0.5?  Who, aside from the French, would have done that?  Any writing on it?  "Le Moteur Petit" maybe?

[Rick_Huff]

Tim,
It is an M3x0.5 bolt.  There's no writing on the engine itself, but I found some writing on the capacitor.  The temperature rating is in Celsius and there's an umlaut over the "u" in one of the words, so maybe German? 

Rick

[Tim Wescott]

The umlaut could be German or various Nordic languages.  Or it could be a German cap on some other nationality of engine.  I wonder if it came home from Europe with a WW-II serviceman?

[Bill Mohrbacher]

Rick,

Thanks to German MECA member Holger Menrad's (sadly now deceased) compilation of German engines your engine is a Felgiebel 7.6 cc (abt .45 cid) about 1939 vintage.  That explains the German markings, metric treads, and the ZK spark plug.  These were Selbstbau or home built engines thus there will be variations.  I think your engine is the top one on both pages, the one with no head fins. Yours also has a different rear cover mounting, looks like a 2 bolt instead of the three bolt on the drawings (just like Fox started about 10yers later).  Also yous has fixed points, no adjustable timer.

Another mystery solved courtesy of MECA, the Model Engine Collectors Association ( www.modelenginecollectors.org )

It well may have been brought here by a GI.  Interesting engine, but condition, condition, condition.  PM sent.

[Rick_Huff]

Bill,
I think you've figured it out.  Thanks!
Rick