Start your engine – Work in Progress

I had second thoughts about starting a new project. Then I read the article on Vintage Wings of Canada.

It was fitted with a massively complex 24 cylinder Napier Sabre engine, one of the most complex piston engines ever built.

The complicated “H-24” cylinder Sabre had a displacement volume of 36.70 litres with an output ranging from 2,000 to 2,500 hp for the first 2 versions with an astonishing 3,000 hp in reserve (injection of a mixture of water and ethanol).

This complicated and heavy engine had 48 spark plugs, and weighed in at 1.1 ton sitting on a repair stand. Its fuel distribution was through a system of sleeve valves. To start this monster, the Typhoon pilot had to set the throttle to five-eighth of an inch and no more, otherwise there was a risk of drowning carburetors in avgas with a resulting engine fire. The ignition of the 24 cylinders, using what was called the Coffman System, was affected using a shotgun-style cartridge. As the cartridge exploded, the propeller rotated about 450º. At that point, with the cylinders full of gasoline, it was a must for the engine to successfully start, or it had an 80% chance of catching fire at the next attempt. The fuel had a very high octane rating, the Typhoon taking only 130 octane grade gas. Before starting the engine (and during the flight), the pilot was obliged to wear an oxygen mask because the cockpit immediately filled with carbon monoxide exhaust. The Napier Sabre engine had an awesome decibel output, sounding nearly five times louder than a Merlin. The vibration caused by this beast was disconcerting to the inexperienced pilot.

I just  had to start because  once I get starting with a project I just can’t stop.


3 thoughts on “Start your engine – Work in Progress

  1. Gee, no wonder there aren’t any Typhoons on the warbird circuit! Just the thought of an “H” block engine makes me shake my head…

    I hadn’t noticed the 130 octane part before. What a beast!

  2. There is a project currently running here to restore a Typhoon to flying condition. Hopefully it will happen and we will see one grace our skies again. Like its sister the Tempest, they wreaked havoc on enemy ground targets, a potent weapon indeed and not one for the feint hearted!

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