Oddball engines and prototypes

[katinas]

Perhaps trying to maximize bottom end power for stadium Superenduro ???

Everyone who tried it are very satisfied and yes much better througth rev range than older ones.

Upd. After 16 hours of run, piston ring snagging again. Very clear boundaries of piston dome color.

[Pursang]

Here is a video with some interesting moments (and a fair bit of Seppo Youtube Wankerism)

https://www.youtube.com/watch?v=LyI3KWMWbB4

Tip: watch without sound, pick through the bits with the viewing peaks.

Overview: 3D printed carbon fibre reinforced piston fitted in an old quad bike.

Test run: repeating slow U turns and accelerating, up to 42 mph.

Results: lasted 1min 30sec. Top ring separated and stuck in top of bore.

Melted crown, but skirt and gudgeon pin looks OK. (Go to minute 26).

My Take: Idea has some potential, if development and testing is done under controlled conditions.
eg, I think, at one point, some extra height was arbitrarily added to the crown. If it was detonating it would probably be quieter than usual.
Perhaps it needs an alloy insert to protect the crown and conduct some heat through the rings.
Different combinations of carbon and poly might be more heat resistant.
Perhaps oven/kiln baking to reduce the Poly and Set the carbon could work. Lots of ideas to investigate. Please let me know, when You get it right!

[ken seeber]

Firstly, I have to agree with your introduction words Dazza.

Irrespective of the clearances, profile and squish, a few things come to mind:

The ring groove. As the seat of the groove must be very flat and smooth for ring sealing, I’m not sure how good this could have been, direct off the printer. Despite being a flat surface in the X & Y directions of the print head, there is every chance for some waviness and minor projections. This means leakage = high temps = death.

From some views it looks like some form of ring anti-rotation is present. As they didn’t mention an actual pin, then one can assume that it was a printed projection at the base of the groove. This would prevent any lathe turning to smooth up the groove.

With the much lower thermal conductivity of the printed material being far less than aluminium, the crown surface temp would inevitable been very high. As the glass transition temp of even the highest temp printer materials is around 180C, there is the likelihood of bits just falling off, just as in the vid = death.

Not sure if they reamed out the piston pin bore and what form of retention was used.

It just shows that aluminium is pretty good stuff.

It also shows than many things can be made to work, it’s just a matter for how long.

Anyways it was interesting, to a point.

[katinas]

Long time ago, carbon piston was tested in small RC engine. Working fine, but after some time the piston deck starting to crush.
Add other carbon piston photos, first from Arctic Cat testing program.
.https://core.ac.uk/download/pdf/42785511.pdf

[R650R]

Stolen from Facebook - Here's an engine rarely seen since they were intended to be disposable. This is the 4 cylinder radial engine from a WWII German G7A torpedo. It ran on Decaline fuel (decahydronaphthalene), which was first burned using compressed air (stored in a tank onboard) as an oxidizer. The combustion byproducts were then passed through a device called a 'wet heater', which also introduced water (from a 57L storage tank) to produce superheated steam. This high pressure mixture of superheated steam and compressed air was finally sent through the engine to drive the pistons.
Since the entire internal combustion/steam generator system was self-contained inside the hull of the torpedo, it could run underwater. The 4 cylinder, 'X' type radial engine produced up to 350 horsepower at its maximum power setting, which was enough to push the 26' (just over 7 meters) torpedo (the length of a large Uhaul moving van here in the States for comparison purposes) along at nearly 50mph while submerged.

Very cool. This is probably where most of the “engines that run on water” prototypes start from. It’s a great idea in principle as steam is the single most efficient transfer of heat to mechanical energy. However no one can make a piston/cylinder combo that will last longer than the life of a torpedo run. Apparently the steam has a cavitation type corrosion going in this environment. For some reason maybe the larger bore sizes and slower speeds not such a problem for locomotives

[husaberg]

Classic motorcycle mechanics ran a story on a guy building engines in about 1982 84with the new then PEEK aka teflon
It had ceramic coated domes.
if I was doing one I would use MCM or plastic ceramic coated with sleeves to run the rings in

[pete376403]

No substitute for cubic inches - Nordberg two stroke radial startup

[Pursang]

[lohring]

What a mechanical engineer's dream. Why they aren't investigating much simpler 2 strokes with their electric turbocharger is a mystery to me. Even a conventional 4 stroke combined with this turbocharger should allow a standard engine that can recover exhaust energy like was done in Formula I. The bottom line is that battery electric power is going to replace IC engines in cars and probably trucks, not because of government rules, but because they will last longer and are much less expensive to operate. I'm concerned that Chinese electric cars will destroy Germany's' car companies.

Electric cars haven't found their way into the popular consciousness yet since there aren't many electric cars on the road. As companies learn how to build electric vehicles the cost has come down to the cost of IC vehicles. Today I can buy a Tesla Model 3 performance version for close to half of what I paid in 2018. My car still runs well after 118,000 miles, saving over $2,000 a year in fuel costs alone. Its performance and handling is far better than any car I've owned in the past 60 years. The Supercharger network allows long trips even though Superchargers aren't as common as gas stations yet. Just got back from a 1,000 mile each way trip, and have gone on trips as long as 2,500 miles each way.

Pepsi has been running Tesla semis with very good results. The charging network is just starting to be built for these trucks. All this has been done over the last 12 years with little or no government help under an administration that can"t say Tesla, a company run by a very unpopular major stock holder.

Lohring Miller

[lohring]

https://autos.yahoo.com/fleet-operat...110057665.html

Lohring Miller

[katinas]

Some photos from The Italian Air Force Museum.
The piston cavities above the pin and one of the first piston opposed engines, 8 cylinders four stroke.

[Pursang]

A lot to like about this idea. Pretty Damn KISS!
It might be a '4 stroke' cycle but it is valveless!

[Pursang]

What a mechanical engineer's dream. Why they aren't investigating much simpler 2 strokes with their electric turbocharger is a mystery to me. Even a conventional 4 stroke combined with this turbocharger should allow a standard engine that can recover exhaust energy like was done in Formula I. The bottom line is that battery electric power is going to replace IC engines in cars and probably trucks, not because of government rules, but because they will last longer and are much less expensive to operate. I'm concerned that Chinese electric cars will destroy Germany's' car companies.

Electric cars haven't found their way into the popular consciousness yet since there aren't many electric cars on the road. As companies learn how to build electric vehicles the cost has come down to the cost of IC vehicles. Today I can buy a Tesla Model 3 performance version for close to half of what I paid in 2018. My car still runs well after 118,000 miles, saving over $2,000 a year in fuel costs alone. Its performance and handling is far better than any car I've owned in the past 60 years. The Supercharger network allows long trips even though Superchargers aren't as common as gas stations yet. Just got back from a 1,000 mile each way trip, and have gone on trips as long as 2,500 miles each way.

Pepsi has been running Tesla semis with very good results. The charging network is just starting to be built for these trucks. All this has been done over the last 12 years with little or no government help under an administration that can"t say Tesla, a company run by a very unpopular major stock holder.

Lohring Miller

In Kiwi Biker Land we tend to have a preference for the max HP option. High volume manufacturers are subjected to increasingly strict emissions regulations and must comply, to stay in business. A little, additional, but basic, mechanical complexity that reduces emissions and still maintains a high performance output is worth investigating.

[lohring]

According to a friend who worked first at Eco Motors on electric turbos and now works on this project, Porsche is considering this technology as well. I think it would be an even better solution for two stroke diesels like the Achetes opposed piston engine. Running on hydrogen their engine would have essentially zero emissions.

Lohring Miller

[Pursang]

Here is another, more independent, look at the Omega engine.
Better idea of the operation and some plus & minuses.