The First World War witnessed a lot of horrors and some of the best scientific innovations from 20th century. One of the them was the wide usage of aircrafts that used rotary engines. In these power mills, the crankshafts stay stationary while the other part of engine keeps rotating around it. There aren’t many rotary engines from the First World War that are in use these days, however, a small machine shop in New Zealand has been working very vigorously on this issue. You can always order a brand new rotary engine from this shop. Apart from creating vintage aircraft parts and several other usual machining services, the Classic Aero Machining Service is busy creating the 1915 Gnome engine with present day technologies.
Tony Wytenburg, the Chief Engineer and Managing Director of the Classic Aero Machining Services likes to explain about it, “ Our idea was to produce original rotary engines which were safe, reliable, and affordable. I’ve been in business since 2004; I can’t say I enjoy everything about running a small business, but I do take great satisfaction from making parts. Being able to make a lot of parts which, when finished, is a running engine is one of the most satisfying things I’ve ever done.”
The workshop engineers actually reverse engineered the original engine. They drew the parts on CAD and used GibbsCAM for their CNC mill. It allowed them to import the CAD models and use those to generate the G-code. For their manual machining and CNC lathe they used CAD models to generate working drawings. The engine developed by this workshop is capable of producing 115 horsepower against a peak torque of 580 lb ft. Cylinders for this engines were machined from billets just like all other parts of the engine. The only casting done on this engine is that of the oil pump body. The company also forged aluminum pistons that utilize the standard car piston forged blank.
In order to stay eco-friendly, the team used castor oil as lubricant, it is the very same lubricant that was in use in year 1915. It is a constant-loss oil system that consumes 10 pints on an hourly basis. The team was also keen on using some modern day oils, but money crunch restricted their means. In terms of carburation, they are using the standard fuel. The engine is compatible enough to work with both automotive gas and AV gas.