BE-4
| Name | BE4 | Designer | Miroslav Bedřich |
| Type | CI Homebuilt | Capacity | 4.5cc |
| Production run | unknowable | Country of Origin | Protectorate of Bohemia and Moravia |
| Photo by | Bert Streigler, Ken Croft | Year of manufacture | 1942 |
Notes:
This single cylinder compression ignition engine is a Czech design called the BE-4 which, according to Jiří Linka and Jan Kafka's book, dates back to 1942 and is credited to Miroslav Bedřich. The engine pictured above is part of Bert Streigler's collection. The engine was initially designed for home construction, which figures since it was done in 1942! Notice that the crank case of Bert's example and a certain watzit features a set of webs from journal to the front face, while the picture from Jiři's book does not. I'd guess that as the engine was published for home construction, many were probably cast at home from pieces of passing B17, or whatever, so variations might abound.
A somewhat "cleaner", more modern version appeared many years later. This one has a more rounded shape to the cylinder extension of the crankcase and has "BE4" cast into the exhaust side of the crankcase. Jiři credits this to Ladislav Davidovič and labels it a "Replika". Apparently a fair number of these were made in the 1970's and have gradually found their way all over the world.
This example was spotted by Ken Croft adorning the nose of a large cabin model at an Old Warden meet some time back. This is clearly an example of the Replika engine, as another shot showing the "BE4" cast into the port side confirms.
But Ken thought he knew of yet another version and sure enough, a day or so later, he provided this advertisement showing a rear induction version fitted with an R/C throttle and having a distinct Barbini feel to the upper crankcase around the exhausts (we suspect that what had been an inlet mounting flange on the side-port version is another exhaust port of this version). The asking price is a bit steep, but Ken says that John Hook of Flighthook is a great bloke, having climbed the unclimbable tree to retrieve one of Ken's wayward models some time back.
Of his example of the engine, Bert says:
The plans I have were cleaned up and archived by MLADEHO KONSTRUKTERA sometime between 1946 and 1950. I think that translates as Model Builder? Anyhow, it was a magazine and the drawings, still dated 1942, were published in that magazine in 1960. The engine I have is built in accordance with those plans. It is a whopper of a thing, standing 4 3/4" tall! It has a bore of 16mm, stroke of 22mm and a displacement of 4.5cc. Weight is 300gm, or about 11 ounces. He recommended a 380mm x 220mm prop, which works out to be about 15" x 9" pitch. RPM is said to be 5500, producing 1/4 HP. The recommended fuel is 11 parts kerosene, 6 parts oil and only 3 parts ether.
The engine I have is obviously old and worn. The prop drive and spinner are someone's replicas. The exhaust stack is probably from one of the replicas built later. The intake is about crude enough to convince me it is the one that the builder did. These engines, curiously, used a screwed in place crank throw - risky for a diesel in my opinion.
