Alternative Engine Tech

[Mark BEX]

I like the rotary engine by Liquid Piston. It is a new take on the rotary engine.

How can anyone see that a company that has been around flogging this to investors for 20 years now, is nothing but a scam?

They have acheived a 50cc engine they put into a gokart, and the thing barely moves, it can't have more than 5 hp from what I can see.

The engine suffers worse than the Mazda Rotary for two very basic reasons, compression buildup is too slow, and too much surface area for the combustion. So what happens is the charge firstly loses it's heat while compressing, and then loses it's heat when it's expanding (burning). Then there's the problem of shading, too much area that the fuel doesn't get burnt, the reason Mazda rotarys need 2 spark plugs in each chamber

New notice from LQ => (Link)

Our latest engine, the XTS-210, is getting primed for market!
The XTS-210 engine is a 25-horsepower, two-stroke, supercharged, and liquid-cooled 210cc engine based on our X-Engine™ technology platform


So this LQ engine, what the heck can a vehicle with a 210cc/25hp LQ motor get? I need to see it in a motorcycle or micro car before we would know for sure.

2 stroke, motobike 250cc engines were getting close to 50 hp 30 years ago, and now over 50hp with EFi. BTW, the 250cc 4 strokes are over 45hp now, and not much heavier.

Evinrude 2 stroke outboard boat engines are so clean, they top the list of California Rivers EPA rankings, the stricktest in the USA, and changed the oprressive Californian 2 stroke laws that had them blanket banned.

So I don't know what the extra complications of supercharging is about to get half the HP ... looks good for "investors" I guess ..

 

[AriLea]

They are thumping about having a military contract. We will have to see a consumer product to confirm thier claims.

I know that they say the heat losses are less because the rotor is not coupled to anything, and the hot spot is only in one little location. But I don't do thermal flow engineering. So how would I know about thier claims?

Doesn't mater much to us if they never present a consumer product that has thier engine in it.

 

[BigWarpGuy]

Perhaps the InnEgine is an alternative engine?

Perhaps it has potential?

 

[BigWarpGuy]

Here is another alternative engine? It is described as a Scotch yoke engine? It is by ASF Sytech. they describe it as a non-boxer engine?

 

[BigWarpGuy]

Perhaps another alternative engine design? Popular Mechanics article.

 

[DikiJ]

I should disclose, I wrote a paper for the SAE back in the 1980's. It was the results of a multi-fuel technology. (still have a copy of it)
The engine we tested had our special carburetor adaptor. It could switch between 'petrol', CNG and Propane.

This LiquidPiston engine should be able to do all of that plus Hydrogen and Diesel without significant hardware changes. Fuel storage and pluming becomes the limiting factor at that point.

That feature, if provided on very many cars, would undermine the monopoly that each fuel type currently has over it's individual sectors.
Petrol and Diesel would likely need to be separately stored, depending on how the oxygen sensor is engineered into the system.
It's relatively easy to combine Hydrogen, Propane and CNG in the same tank. This is because one gas is fully consumed before the next one starts to boil out.

At one point (in 1980's) CNG was a lot cheaper per unit of energy than Propane. But CNG did not store very efficiently. So if you have enough CNG in one tank for average use, it would consume the CNG first and the propane was kept in reserve for those longer trips.

When the propane started boiling out, the O2 sensor would see the change and auto-adjusted the carburation.
How to properly top off each fuel type would take some more engineering design work.

I put a kit on my generator that lets it run on gasoline, natural gas or propane. To use propane I have to borrow the regulator from my gas grill. The generator runs fine on any one of them.

 

[AriLea]

Perhaps another alternative engine design? Popular Mechanics article.(see image above)

And then there is that rotating revolver style, with opposing heads. All I can figure on that one, is that the two pistons have all the heat bound up in the top of the pistons, so not all that much is leaked. When the pistons pull apart the heat is decompressed, with little going into the actual cylinders. And it is easy to make those pistons out of metal-ceramics or something that doesn't transfer as much heat into the cooling system.

In a standard ICE, the heads and valves are always exposed to the heat, and the cooling system has to keep them from becoming hot spots. That's a loss of heat. But in the revolver style no valves or heads exist or see any of that heat. And hot spots do not form as easily.

What I find hard to accept about Liquid Piston, is that all those fast sliding tip seals, and are prettly large areas. So, well, do they really seal all that perfectly? Plus it does have a lot of area to loose heat into. Granted the spinning center piece is not strongly coupled or grounded to any cooling system.

 

[Mark BEX]

Here is another alternative engine? It is described as a Scotch yoke engine? It is by ASF Sytech. they describe it as a non-boxer engine?

Wow, haven't seen that for a while, and if you search long enough, you will find a road test and report on the total sum of it.

It was a little bit better, but not a world beating step forward, but i'm guessing this company will have an "investment" option .....

Ha, just looked, yup, has "investor center", what a surprise.

What was the name of that Slade song again ...

 

[AriLea]

You know, if I were to investigate novel engine designs for the best thermal retension, I'ld start with the opposed pistons, who's cycle is modeled on the left below, and requires valves, and probably 4 cyles in four strokes (two full rotations).
But I'ld consider staggering the two cranks, modeled on the right, and just maybe, that allows it to become a two-cycle in two stroke (one rotation). This allows exhaust ports on one side, and intakes on the other side, with no valves at all.
Moving the center of the cranks, and relative cycle between would allow all kinds of dynamic adjustments for RPM and power demands.
This is a lot like the ported rotary, except all the hot spots are inside a nutshell at center of the pisions. Very careful placement of a spark point is needed unless that can be routed somehow through the middel of the pistons themselves. Which I think has been done before.

On the other hand, maybe this needs more mechanics engineering to get useful changes in the cycle, so my bad.

Just saying out from the tickle at my rear...oops meant my ear.

 

[Mark BEX]

But I'ld consider staggering the two cranks, modeled on the right, and just maybe, that allows it to become a two-cycle in two stroke (one rotation). This allows exhaust ports on one side, and intakes on the other side, with no valves at all.

It's a very common engine, you don't know? I'm surprised.

Over the years, thousands of them in ships, trucks, industry, trains, etc, many made by Fairbanks Morse, and well known in Junkers WW2 aircraft.

The most famous weird one of them all, the triangle Napier Deltec found in thousands of diesel locomotives world wide. Up to 88 liters and 5500 hp

Well explained here