Whether it’s offroading, auto cross, dirt bikes, snow machines – whatever it is, all such vehicles have gasoline or diesel internal combustion engines powering them, and in turn we all have a little bit of 10w30 floating through our veins.
It should come as no surprise to anyone then that we, like everyone else in this hobby, channels the 5 year old inside of us when it comes to piston-powered aircraft engines of yesteryear. And the mack daddy of them all was built by a small British aeronautic and engineering firm as a private venture way back in 1933.
Coming in at an incredible 27 liters, the Merlin was a liquid-cooled V12 double overhead cam aluminum engine. Going through a number of design variations as it was perfected, the engine we know and love today was known in-house as the Merlin 60 and 70 series. Following the outbreak of World War II, the Merlin was also produced by American company Packard, who RR felt was the only contractor that possessed the skills and craftsmanship outside of Britain to produce the engine.
Featuring all forged internals, and a fantastically complex two-stage, two-speed roots type supercharger it boasted a maximum ceiling of 40,000 feet on 130 octane aviation fuel. Measuring physically at just under seven and a half feet long, and 1,640 pounds dry, this was one huge engine, even by the standards of the day. At full-rated power of 1,580hp, the engine consumed 130 imperial gallons of fuel per hour through twin-choke, updraught Rolls-Royce carburetors.
The engine also consumed enormous amounts of air. At the same full power rating, the engine was eating through the equivalent air volume of a single decker bus, per minute. It was discovered that with this enormous amount of air intake and fuel being burned, the exhaust gasses were exiting the manifolds at over 1,300 miles per hour. So by simply angling the exhaust manifolds back, RR came up with new “Ejector Exhausts” that offered an additional 70 pounds of thrust at 300mph, and increased the maximum speed by 10mph.
With nearly 150,000 of these engines built across the US and UK, the Merlin was one of the best engineering efforts of the war. Over 80 years since its debut, the engines live on today in racing planes around the world as one of the best engines ever built.