I’ve got a Popular Mechanics magazine from the 1950s that describes the benefits of these engines as follows:
[ul]
[li]Higher fuel economy[/li][li]Fewer moving parts[/li][li]Quiet[/li][li]Low vibration[/li][li]Able to burn different types of fuel with little to no modifications[/li][li]A better horsepower to weight ratio than convetional engines[/li][/ul]
And yet, a google search turns up no instances of them being used today for anything. About the only thing I can find on them is that research is being done on them in a few places. So, anybody know why they didn’t become widely used since they seem to be so promising? (The were used in German subs during the war, but that’s been the only use I’ve been able to find of them.)
I saw that, but according to the article I have, there were a couple of European companies before WW II that had
So somebody was working on them for a while and they were actually used. After the US Navy captured a German sub with a free-piston engine on board, they turned the engine over to a bunch of researchers at the General Machinery Corporation. At the time the article was written, General Machinery was in the process of building a 4,000 HP locomotive for a railroad.
Based on that, one would think that they’d at least worked out enough kinks to get the thing going. Yet, until I stumbled across the article, I’d never heard of them.
Not the same…The Dynacam rotates a crankshaft (as does a regular piston engine); the free-piston engine uses the piston’s “up” and “down” motion to power a hydraulic pump.
I can see this engine doing okay at lower speeds, but I dunno about higher-cycles/second… it would be much easier to make a BIG & slow engine, say for a ship though. And it would have much less vibration than any crankshaft engine, making it a reasonable choice for a military sub.
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And by the way, I thought all the University of Helsinki worked on was cures for baldness… - DougC