V4 Heisler

When Charles Heisler was filing his locomotive patent in 1897 he made sure to include a V4 variant of the engine. This engine has a crank angle of 180° and a bank angle of 90° to give near perfect balance which is not achievable with the standard V-twin engine and would have made it exceptional compared to a lot of shays which didn't even have any balancing weights.

Each bank has piston phases that are 180° appart. This allows for one valve gear with a rocking bar extension to be used for each piston bank like 4 cylinder simplex engines. With this arrangement compounding is possible although much more design work is required to make it ideal. Because it has perfect balance and increased power in a compact form factor a V4 engine is the ideal type for a Heisler.

Unfortunately, we don’t have any documentation to prove this locomotive design was ever built. A G-gauge model has been made which proves the principles of the engine work.

Schematics for building this model locomotive can be found in Live Steam Magazine articles: