The Legendary Napier Deltic - 88 Litre Opposed 2-Stroke Triangle Engine

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15:33 min.

Curious Droid

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. In the mid-1940s the British admiralty was looking for a new high speed, high power diesel to use in their motor torpedo boats, they turned to Napier to come up with a new engine and the result was the most powerful diesel in the world for its size and weight that went on to power Navy boats, locomotives and even the most powerful fire engine pump in the world. This is the story of the Napier Deltic super diesel engine.
Each cylinder has two pistons, that come together in the center of the bore for a firing stroke. NO cylinder head, but 2 crankshafts.
These were used by the British rail ways to power locomotives until the 1990's
Very interesting engine design.


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3 crankshafts, 2 going one way round, one opposite. There is a railway museum near us with several of these engines, they are absolutely fascinating to any engineer