Well, I must say that the Napier Deltic and the Commer TS3 were amongst the most successful, but we must admit they owed their existence to some original German designs (Deltic owes it's existence to the Junkers Jumo designed for E-Boats and the TS3 to Sultzer).
I used to sneak into the local scrapyard on the way home from school most days (the teachers etc would have frowned on me for being so "common") where there were two Bristol Hercules engines from a crashed Wellington bomber lying on the heap just begging to be taken away and preserved. They were amongst a tangled pile of broken aircraft, this particular one had crashed during WW2 into a cliff face just a few miles away and had hung there for well over 10 years before being removed.
I was always trying to find a way of getting them home but I was only 14 or 15 at the time so didn't ever stand much chance of that! - pity to see them going to the pot, but that's how it was I guess.
Strokers Galore!
Here's another X4, this one is the JJ2S X4 500, under development in Poland.
It features an inverted piston with ports which give it functionality similar to a sleeve valve. I think this configuration was first suggested by Draper, and Flettner has tried something similar.
The JJ2S pistons are also stepped, to provide primary compression. Drawings and animation showing the operating sequence are here:
http://jjsdesign.net/jj2s/zasadadzialania.html
Some more info here:
http://www.jjsdesign.net/jj2sx4500/jj2sx4500.html
Some of the drawings show a single cylinder engine with conventional crankshaft, however, the X4 has different arrangement "Both pistons, each mutually opposite pair of cylinders are mounted at the ends of a double yoke. The two double yokes, arranged mutually at right angles, extend over a common, but a double eccentric, which is mounted on a single crank pin of the crankshaft normal. Stroke journal is only half of the piston stroke, which the other half takes over and performs eccentric. With a small radius crank crankshaft becomes very compact and rigid. It should be emphasized that the pair of eccentric strength compensates for one pair of cylinders in relation to a pair of second, and as a consequence, decreases with increasing rotation of the crank pin load. There is therefore a, the engine is particularly suitable for operation at very high speeds"
I didn't see any updates during last 3 years! I hope they didn't run into problems.
http://www.jjsdesign.net/forum/viewt...3e09f938dbfc64
Here are more info about 1cyl version, there are videos and other stuff. There is no progress about 500 because there is no money to develop this further right now...
Thanks Muciek, I was looking for the photos of machined piston and other parts, and found some of them again with link on that page:
http://jjsdesign.pl/jj2swg125/index.html
An amazing piece of machinery, quite complicated and a little bulky (in a funny sort of way). Still haven't studied it enough to get my head around the crank setup but at a glance it seems to have similarities to the "PAUT ENGINE" (which I brought up way back) - just about the best animation I've seen to date - if nothing else!
They say a picture is worth a thousand words, I say a good animation is worth a thousand pictures.
https://www.youtube.com/watch?v=pqJchMWiqoE
Strokers Galore!
I'd say at 24 frames per second that would be a rather short animation.
Joking apart, it's an interesting video.
Nice to see how those 180° crank throws serve a 4x90° hypocycloid engine (sort of; each 90° angle is between a pumping cylinder and a working cylinder).
I wonder how long before Flettner builds a 90° V-twin along these lines.
Strokers Galore!
Husa / Grumph, That's a pretty good article (and drawings), pity the British industry was almost on the way out then - that could well have been the start of something new. The fact that it was a gradual sort of development using available parts and not an out and out attempt to build a world beater would have stood it in great stead.
Strokers Galore!
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