Tom, you're being way too generous in your assessment. Not wrong by any means, but giving Cyclone the benefit of the doubt that they don't deserve.
You said "Of course, every single element of the argument assumes world-class efficiency (or better) and I have seen no indisputable proof that real world testing backs up their claims. For that matter, I have problems believing they even performed calculations beyond the most theoretical in nature."
First, not only is there no indisputable proof anywhere, but there is no anecdotal evidence that any real world testing was done. There have been some really short videos of engines spinning, sometimes even with a dynamometer connected, but none showing an actual load being applied and power measured.
Even then, this was all bench testing (if you can call it testing). As for real world, there have been two boats built, two land speed record cars, a truck chassis, lawn mower, weed eater, generators, etc., and none shown running in public. Not even at the shareholders' open house in 2011. We are told the Army genset passed its acceptance test, but not a hint as been give out of what that test was.
Harry had once promised to publish dyno test results for the Mark 5 land speed version on the steam car board, but then weaseled out under a variety of excuses. The last was the SEC wouldn't let him. Considering the engine has to last less than 5 minutes in a land speed run, Harry's inability to do a dyno test is strong evidence the Mark 5 can't survive for more than seconds while producing any power.
The performance predicted from calculations is not just based on the most optimistic assumptions, but on ignoring thermodynamic theory altogether. Harry's calculation was removed from the Cyclone website after links to it started appearing on this board, but it's still available at the Internet Archive:
It's techno-gibberish. It's like something done by a school kid on a math test where they know the kind of answer they want but have no idea how to calculate it. Numeric values are just pulled out of air with no justification. No knowledge of thermodynamic theory is evident.
For example, on the first page it says "Indicator Diagram hp = 131". An indicator diagram shows the pressure acting on a piston top as a function of piston stroke. Between the top of the piston and the end of the crankshaft there is friction in the various parts, plus loads from other engine components (pumps, fans, etc.). The brake horsepower of the engine is the indicated horsepower minus the friction and auxiliary loads, i.e., what Harry called the "Mechanical losses". These total 12.25 hp, based on numbers pulled out of the air.
So now Harry has a problem. He has advertised his engine as 100 hp, but his calculation shows it should produce 131- 12 = 119 hp, which is 20 hp too high. What's he do? Makes up "Thermal losses" that come to the 20 hp he is trying to get rid of.
Theoretically the trouble with this is there are no thermal losses between the top of the piston and the crankshaft output. The calculation is dead wrong, but Harry's prediction came out to the number he wanted, which was his goal.
Even so, the engine efficiency only comes out to 23.2% on the second page. Much too low for Harry's needs, so out of nowhere comes a 4.05% air side and 4.32% water side efficiency gain from the heat exchangers, which magically push engine efficiency up to the 31% he wants.
The last Mark 5 engine video from February of 2015 showed all the heat exchangers removed, so they obviously didn't work anywhere near as anticipated. Yet, this 31% efficiency number is still being trotted out by Harry and Frankie on Facebook.
If you right click on that calculation document and select Document Properties, it shows the author was Frankie and the creation date as 3/18/2009. Cyclone has had 8 years of accumulated failures and let's say $20 million of spending since then and they know fully well their 31% efficiency claim is pure fantasy. Yet, it still gets used.
By the way, here is an annotated screenshot of the last update on the Mark 5 from almost two years ago now. Other than pulling off most of Harry's inventions there was no progress on the engine since the previous video of 2010. Want to bet there has been no progress since 2015?
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