Engine designs: Where did they go?

Ha! Ha! Just read a complaint that summer DOW gets quiet and boring.
SO . . . . just why do we all use round, up and down piston; connecting rod connected; crankshaft driving; poppet valve breathing engines, eh?

Because it has evolved out; stood the test of time; and proven to be the best for changing fuels needs; better lubricants, better more precise manufacturing and controls systems.

Search up the wikipedia and read the article on the Knight sleeve valve engine. An American innovation, slowly lost out to better direct mechanical driven poppet valve engines. Not in this article was a late 1980’s effort to revive/update this design with then much better lubricating oil to solve the problem of the moving cylinder sleeve valve from carboning up and sticking. And in high power density applications (like economy cars, racing, aircraft, motor cycles) even with late 20th century computer aided design improved the cylinder filling efficiency of the sleeve valve; it was still less than a modern poppet valve engine filling/purging capability.

And on poppet valve engines - why spring types? Why not ALL “better” desmodromic direct mechanical opening AND closing? Ducati and a few others.
Ahh . . . manufacturing costs. Maintenance costs. More sensitivity to world wide, year around climatic operations.

And then the much vaunted many-less-parts Wankel. I have an automotive training manual from early 1973 that shows a layed out a 150 hp American small block V-8 versus a Mazda bi-rotor 150 hp Wankel engine showing the obvious superiority of less parts, potentially lower manufacturing costs, smaller package and less weight.
Ha! As events have proven that 150 hp was at a cost of a higher grams per/hp/hr in fuel consumtion. Got well proven to be a relative fuel-hog in cars, light trucks, light aircraft, motor cycles and small generators versus equivalent piston engines.
Higher engine produced emissions per hp used too. All of that swept internal surface area heat quenching.
And manufacturing cost are first most related to scale of production. Small lot scale means higher per units costs. It was the 1990’s and forward that the new CNC machining centers made tiny displacement multiple cylinder poppet valved engine an affordable scaled production reality. Not just Formula One dreamers engines anymore.

And so, once again Steve Unruh: Just What and the Hell does this have to do about woodgasing??

The side jetted, constricted throat, grate supported wood-char bed, DOWNDRAFT system is the one that has evolved out over a time span of 130+ years and hundreds of designs/designers to be the overall best solution for making engine grade woodgas.
Digging back through my note books from 2007-08 I am actually embarrassed now by my gilding-the-pig better ideas.
More complex, yes. Harder to build, yes. MORE maintenance points, yes. Better?? No.

So, beware the Piped-Piper not-solutions, just because they are new and seem exciting.
Boring, is good, solid, and practical-proven.
tree-farmer Steve Unruh


I heard about the achates power engine earlier this year, I thought it was exciting, as it loop scavenges, no valve train, fuel injected…lots of sound features, opposed pistons should make for a smooth running engine. http://achatespower.com/our-formula/opposed-piston/

I also thought the Federal Mogul new cylinder coating seemed promising, I haven’t found a real example of it yet… could be a bit of awesomeness in it’s applications. http://newatlas.com/federal-mogul-piston-coating/42594/

Oh well back to my exciting job at hand, of sawing used bricks to save a few bucks.


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we have this guy, he restored the old car with a gasifier, build some nice other things also… ( can’t remember his name and post at this moment… )

How you like his Free piston engine ? i want to try that on woodgas…


or this one…


I see David Hagen’s named ain the credits of one video. Wonder if that is the DH that post on this site. Surprise that work is stilling done with the Knoght sleeve valve engine.WWE had a cut away Knight engine back in the late 50’s when I was in college. TomC

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Daniel Hagen it is…

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Then there was the “McMaster Motor”:

I worked with the inventors brother for many years in a 3M lab. After we both had retired, he’d keep us up to date on progress. It originally ran on gasoline. Many of us were surprised when the company suddenly switched to the steam-to-hydrogen/oxygen idea. The brother, Clarence (Mack to us) even brought a video tape of its first run to one of our retirement breakfast meetings. I think that was a year or two before this newspaper article was written.
There’s a little more about it at:

They had a website going up till about 5 or 6 years ago, but now there’s nothing.

Pete Stanaitis

Ha! Ha! Well glad to know we all have favorites up our sleeves.

Really for real around the world practicality usages “compromises” must be made. it is the uncompromising designer/manufacturer who falls by the way-side.
Compromises in this case are really just Balancing one set of needs against the current possible doable set of possibilities.
An enduring design will always be the one that Balances ALL the best, for the most users.

As appealing as the two cylinder free-piston engine seems . . . . did you see the shaking??
Put a second phased cylinder pair would dampen that end shake down . . . . and then set up a center point (secondary) rotational shake.
Modern car owners are now spoiled/addicted to extreme power train smoothness and quietness.
Apposed cylinder heads are OK with a single central camshaft/valve push rods out. Older BMW motorcycles, 70’s/80’s Suburu water cooled boxer engines. Over head cam these and then l-o-n-g camshaft driving chains to keep oil leak free. Or l-o-n-g toothed belt drive systems needing 2-3 guide pulleys per side min.
My point is that past the “ideal”, “better” ideal-basic design core; often accessory needs can sink the practicality of a design in real world use.
Look at the long-pathways, spread-out intakes and exhausts systems of radial engine set-ups versus inline or V engines.

So as applied to woodgasing systems:
Max Gasman been the one pointing out that 1920 Imberts evolved to quite a bit more direct simplified by 1940’s Imbert.
Then Nordic ash shielded V and W hearths in the 50’s/70’s stepped up the game even more for durability, versus practicality of manufacturing, versus performance in use.

As simple as a Hammer-Solution may seen there is a lot of hard learned simplification/sophistication to a good hammer!!
Head weight/shape must be portioned to the handle.
Head material/manufacturing must be expreinced-learned/best for the intended purpose. Cast?! It will chip spray-off and shatter! Forged! Or at least solid billet machined to form.
Handle? Make mine American Hickory, or quality ash wood Please. Saves the arm-joints shocking. Can pick up and use in -xx weather to +xxx sitting out in the sun weather. Metals and composites cannot do this range of real world usage.
Ha! Try and see.

So real use engines and gasifiers must prove the needs world around usage.
Not just how fast they can race track around!
Post up limited conditions “numbers”.

Just me - ever, predictable, practical, pragmatic
Steve unruh


Been using a composite handled Stanley with anti vibe for 20 years from -40c to +32 no complaints no tendenitis no cracks. wore out the head on the first one not a thing wrong with the handle. Ground down the head several times Still have it for around the home use.

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Yep. Yep. DavidB. New tech CAN be better with a lot of thoughtful engineering, in-lab testing then, out-in-the-real-world trialing. Amazing video story up on the long development on those new-tech hand tools. Not really a handle. Actually a whole system. Seen their newest titanium line?
My point being that it takes really extensive, expensive development to beat out long evolved old tech in place. Sigh. I once had a wonderful seemed to be weather-proof, all-weather use composite shovel handle that had the traditional muscle-memory intuitive hands placement hourglass shape. Ha! I should have bought a dedicated T-post puller tool earlier. Broke that shovel handle pry-popping up T-posts. WAS wooden cored for the shaping; with a glass fiber overlayed laminate for strengthening and weather proofing. And that bonded overlayed with a smooth see-anywhere red plastic. Never could get that same shovel again. Too expensive- went out of production. Now. straight-dumb-stick fiberglass “unbreakables”. Heavy, all steel black painted “worlds-best” clumsy shovel-clubs. Or, traditional style intuitive to use wooden. I have one fiberglass stick shovel to abuse, all-weather forget. Wooden handled, Hubberd Boot Grease (bees-wax & pine tar) sealed for any long-hours-use working.
Steve Unruh

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Ha! Seems I make mistakes daily now.
In above I said, " . . . often accessory needs can sink the practicality of a design in real world usage."
Wrong word choice: accessory. This means optional, not absolutely needed. Like an air conditioning refrigerant pump. A power steering pump unit. A vacuum pump.
My word should have been engine ANCILLARY needs. That would be a lubrication pumping/pressurizing pump. A cycle starting up unit (starter). A cooling air flow and coolant fans/pumps.

Again. Idealized, new designs must step up right up into the big leagues and meet 21st century/modern needs and expectations. And would only rise to usage IF they exceeded these almost from the get-go.
Users will expect key-twist/button pushing starting up. No going back to hand cranking; or push-pulling a linear axis movement to starting up.
If any time in history, it is now for off-the-shelf; now 10 years in-service proven non-rotary-engine-driven ancillary components.
Variable speed, duty cycle driven lube oil pumps, power steering assemblies, AC pumps, and coolant pumps have been factory installed now for these last ten years. So the component manufactures of these now begging for expanded market users.

Still . . . after my late teens/20’s/30’s years expecting someone to knock IC conventional piston engines out of prominence . . . I gave up waiting.
Internal combustion, round cylinder, connecting rod, crankshaft driving engines are a keep-up constantly improving target to catch, let alone exceed.
Internal combustion of any fuel is a very DYNAMIC constant changing pressure/volume “burns BETTER/Cleaner/more efficiently under stressing” situation.
Not rocket science conditions at all.
Not air-pressure external-combustion conditions at all.
The only thing that I’ve experienced similar to internal engine combustion of fuel for power is firearms propellants within a rifle barrel pushing against the resistance of bullet friction drag; and the resistance of the bullet/piston weight/mass to being accelerated. Open air burning of the propellant powder tells you nothing. And every differently formulated propellant powder has it’s own sweet-spot pressure usage range. Change ANY one thing internal/external to a cartridge loading situation and it is back to square-one of a min 10-15% downloading to work back up to optimal pressure/burn - safely.
Internal engine combustion performance only easily observed under engine heat/pressure/varying internal volume loading-stressing. ONLY in the last few decades has there been the computer modeling possible to give some design predictability. The same computers/math’s made for nuclear reactions and weather modeling.
Already conventional production IC piston engines are using last decade’s developed direct into the cylinder fuel injecting. Now in-production are infinitely variable timing AND LIFT valve systems. And now: variable effective compression ratio systems. True MIller Cycle. Emulated Atkinson cycles. In mass-production engine systems.

Mostly I work with family and some friends 7+ year old systems.
ALL of these systems are present now. They must work, work well for at least a decade for my friends and relatives. Me? 20 years usage - or the final take-it-out of service sacrificial road-wreck. I somewhat over maintain to get this. And only good systems even with maintenance can do this.
Keep up. Or get left behind in the dust bin of histories also-ran’s, and never-ran’s.

tree-farmer Steve Unruh (who reads service/maintenance manuals every single day for sanity in a Believer crazy world)


Try this one video linking off of one that K.V.L. put up:

Hmm. Can’t get the link to correct.
Here is the original article text explain reference source:

Animation video here:



I admire this groups work, seems to be good engineering here, and no vibration in some of their models. It appears that their work is underfunded but that they have good mechanical solutions.

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love to see how one of these new engines would work on wood gas , oh well maybe one day .



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Hello All,

I like Anthony Michell’s “barrel” engine. Variable stroke and compression ratio on the fly. http://theoldmotor.com/?p=119936

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I came across this YouTube video this morning while having my wake up cuppa , thought you engine guys might like to see .



Hey Dave . . . I’ll see you one and raise you one . . . as Australian engineers designed; and probably will go into production for the usages stated. Especially if it gets the interest of the Chinese manufacturers for use in their cars as range extender ICE’s.

Watch through to 16:53 for reference to use as small stationary generator engines.
Watch on to 18:30 for the compression ratios graphic chart showing 11.5 to 1 and 13 to 1 tested.