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Eric Harrell, a well-known YouTube sensation, creates the most incredible 3D printed scale models of all types of engines and yes, they are fully operational.

Harrell has an incredible back-catalogue of amazingly detailed engine models he’s made, with greats like the GM LS3 V8 and the Subaru EJ20 recreated via home-brewed kits of 3D-printed parts.

This is the first time we’ve seen him create a rotary model, however. It’s intended to be a one-third recreation of the Mazda RX-7’s 13B-REW, although Harrell admits that the “parts look right but are not 100% dimensionally accurate” but, regardless, there’s some incredible detail into the model, which even includes LED lights in the rotors that light up to demonstrate how the combustion cycle of the engine works.

We are in awe…

A rotary engine is an internal combustion engine, like the engine in your car, but it works in a completely different way than the conventional piston engine.

In a piston engine, the same volume of space (the cylinder) alternately does four different jobs – intake, compression, combustion and exhaust. A rotary engine does these sam­e four jobs, but each one happens in its own part of the housing. It's kind of like having a dedicated cylinder for each of the four jobs, with the piston moving continually from one to the next.

Mazda may bring the rotary back in the RX Vision, however, there are many disadvantages to the rotary engine which has kept it from being successful. Rotary engines have a low thermal efficiency as a result of a long combustion chamber and unburnt fuel making it to the exhaust.

A prototype engine is on display at the Mazda Museum in Hiroshima, Japan, a 3A rotary engine, originally intended for the Chantez. Mazda last built a car powered by a rotary engine in 2012, the RX-8, but had to abandon it largely to poor fuel efficiency and emissions, which is sad, but nevertheless, it will go down in history as something greatly admired in the automotive industry.

We don't know about you guys, but wouldn't it just be wicked to have a few of these scaled models on display in your house or garage? We surely would!

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