Webra T4 40

WEBRA T4-40:- This is an early 4 stroke engine produced in Germany in early 80's to mid 80's. The T 4 series engines were not that popular but were produced in a number of different sizes from 40's all the way up to a super charged 91 (specifically a 40, 60, 80 and 91 size was available).


Specifications:-

Type 4 Stroke Nitro Glow Ignition;

Displacement Capacity 6.5 cc (0.40 ci);

Power 0.45 Kilowatts (0.61 hp)

Design Features:- 

 Rotary Valve porting
Tooth Timing Belt

The T-4 series engines are very similar in design to the RVC series engines where the valve sleeve rotates at exactly 1/2 the rotational speed of the crank shaft.

Personal Observations:-

I acquired my T4-40 second hand from an engine collector in the early 1990's and I was very impressed by the overall quality of the engine as well as its unique design features. I was anxious to mount it in a model and test it in the air.
The subject that I choose was a 54 inch wing span, scale SE-5 constructed from a Top-Flite Kit designed by Dave Platt, the world famous scale RC modeler.
The combination was an instant success. I am a flyer who demands realism from the performance of scale RC models. They have to look realistic in the air and I find it a real turn off to see any model type flying unrealistically. A WW1 model ripping up the sky is what I would consider particularly irksome about as irritating as watching a scale war bird doing a flyby without a pilot figure in the cockpit.  My SE5/WEBRA T4 40 performs very realistically and the takeoffs and flyby's are breath taking to watch.
The engine is particularly easy to live with. Starting is easy and and it is very tolerant of a variable fuel tank position (fuel Draw is not critical). The rotary valve results in a very quiet runner and I estimate that it is quieter with out a muffler than most 40's are with one. A substantial improvement in RPM's can be realized by running this engine with a glow driver attached. I intend to use an on-board glow driver for my next flight to gain a power margin just in case that it's needed.
I recommend this engine for applications where high performance is not an issue. 

View a short video clip featuring the T4 40 engine:-

After a flight hiatus of 10 years at least I was coaxed into putting her in the air again. What a thrill it was to watch her soar overhead for twenty minutes powered by a sweet running almost silent Webra 40 T4 engine.