Teeny Tiny Micro Model Diesel from Germany

[pirmin]

Upon checking my friend  joachims Fotos it appears that your casting is not for the kratmo 0.3.

The kratmo 0.3 was very limited built during ww2. Interesting is that also at this scale they did not use a Tommy Bar but a excentric crankshaft bearing that altered the stroke to adjust compression.

I have drawings for this engine too,but they are poor copys of a copy and i even had to pay for them 

[Jasonb]

Similar to what is on Adrian's site with the three fixing backplate for the kratmo

https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=461

[pirmin]

thats the same engine Jason. there was even a marine version with a rather long coupling shaft.

[crueby]

Amazing how small a diesel engine that is!  On a big diesel, they have to pump in the fuel under high pressure. How does that work for these little ones? And does it get an exhaust stack like big trucks have?

[pirmin]

Those are compression ignition engines,they usually require ether to run reliably and ignite . Ether has a lower Flashpoint than kerosine solely.  So those engomes usually use a mix of 1 part ether,one part kerosene and one part oil

The fuel is distributed via a needle valve and makes its way into the chamber thru schnuerle porting or a exhcnage in the crankcase pressure

[Zephyrin]

I made this one years ago, 0.1cc (5 mm bore & stroke)
from R. Gordon in an insert of Model Engineer, vol 169, p 566 N°3932. 

the plans are of very good quality though, but it's just very small and difficult to make; not easy to hold the parts between your fingers! 
it had occasional pops but honestly, I can't say it's a runner, in spite of hard work and many pistons, compression only lasted a few brief moments.

[rklopp]

I built three Gordon Nanos and ultimately got them all to run, but it was a heavy challenge. Against all wisdom, I used an electric starter, but it was a weak home-build one, so I did not break anything. I had troubles keeping one of the venturi's glued on and one engine seems to have lost a lot of compression quickly. They are shelf queens now.

[pirmin]

  i have the gordon nano here in unfishied state. after messing up the crankcase 3 times in a row i was so unmotivated to start a 4rth one. it is a realy challenging engine. i have a friend in Finland , he built two and got them to run flawless without electric starter. but , he is a master when it comes to lapping cylinder bores and pistons. i believe he had a swiss friend who used a PEMAMO micro honing device to make him an accurate true bore, and he then introduced 2-3 microns taper in the liner.   upon looking on the drawings from what i see i would also have to make quite a few custom tools .

the engine is pictured in Adrians model engine website ,the designer was Georg Schaub, not much is known beside the article on adrians website and the full set of drawings i have. i have forwarded the drawings to Adrian in hope he can use them to get more informations, but thats all for now

[Admiral_dk]

You don't really go much under 1cc before the mechanical requirements (Præcision) grows by several orders of magnitude to make a runner - especially if it is a CI Engine     

A beginner (in regards to CI Engines) size would be 2-3.5cc.

Per         

[pirmin]

i agree. i already made the Sparey 0,6cc , this was my first build  when i bought my lathe just twoo weeks in the hobby. it was a runner right away. its just at this size of the nano mistakes cant be made. there is no room for it .