Turbines are so EASY!

Hell, lots of people in the Frozen North plug in their regular gasoline cars to keep the engine from freezing. That’s nothing new.

Hybrid? I got your hybrid right here!!

And a possible national security threat…:rolleyes:

Ever since the Wankel piled in, automakers have been too conservative about powerplant tech.

It’s not so much being conservative as being able to find something radically different that is as tuneable as a conventional 4 stroke engine. There are all kinds of wild-ass engine designs people have come up with but getting it to a state that someone will look at it seriously is REALLY tough. I’ve seen some spectacular engines die on the vine for lack of money. A positive displacement 4 cyl allows a great deal of control over the full cycle. The most interesting advancement I’ve seen with that is the Fiat computer controlled electric/hydraulic valve activator. That gives an engine unlimited adjustments for intake and exhaust.

I’ve been wondering for years why nobody was doing that. It would allow an engine to operate a maximum possible efficiency for power output, for any set of conditions.

Oddly it gets spanked by the Ford Focus which is larger and has both better fuel economy and more hp/lb as well as the even larger Chevy Cruze which has better fuel economy than the Focus (but not as much hp per lb).

I dont think it stops the army, the M-1 abrams has a big honkin turbine engine that has seen service in a number of different enviroments.


Just because it exists in a tank doesn’t make it an all weather machine that can sit outside regardless of conditions. I’m not saying it’s a hanger queen but I’d be surprised if it doesn’t need a lot of TLC in colder climates.

As someone who has lived in -40 conditions, I can assure you that piston engines do not meet that standard either.

I am also sure the army isn’t putting “anything for fuel” in the tank and expecting the thing to fire up and move on a moments notice from dead cold in those temperatures. They will be using proper fuel for the temp and probably idling or keeping the turbines warm in by some other means.

I’m not saying it can’t be done. Just saying that if you mass produce it, the mass idiots will demand that it performs at least as reliably as their current gas motor. just hazarding a guess, but the shear dollars in development to testing to ensure such performance are certainly a big part of why the big automakers don’t deviate much from what they have been doing powerplant wise for decades.

“Fuel flexibility” doesn’t necessarily mean “anything in the tank”. My understanding is that indeed cold weather starts are an issue with diesel let alone vegetable oil biodiesel. Certainly an issue as a replacement for the conventional four stroke. But again, not much of an issue in a range extender capacity in which the battery can prewarm the small amount of starting fuel before starting up the extender. Will it get cheap enough for that functionality is the question I have. Simple in that there is one moving part yes, but that moving part moves awful fast and needs to be made just right.

Fuel flexibility also means that you use the cheapest fuel that is suitable to your climate/current weather conditions. If idiots put diesel instead of gasoline in their tanks during a Minnesota winter, no one is going to shed tears over their hardships.

As in, the Wankel cycle engine that powers the Mazda RX-8 and all three generations of the RX-7 before it? :dubious:

If nobody north of Omaha can benefit from the selling points they aren’t going to be part of the market.

If you can’t really run on just about anything (meaning cheapest fuel available), but instead have to by seasonal specific fuel at least part of the year you loose a big selling point.

How do you provide heat to occupants? Oh yeah, we don’t care about that market segment. Even though it is most of North America.
A small market manufacturer along the lines of Tesla might see value in developing it but then it won’t be offered at a price I can afford. I just don’t see any of the major manufacturers being interested in spending the development money for a product with such a limited market potential.

In land area, perhaps, but people buy cars. Farms acreage doesn’t.

A coolant-operated heater isn’t the only way to heat a car’s cabin. It would be trivially easy to provide heat from a turbine car since they produce so much excess heat. In fact, this would probably be a big selling point in cold climates since you’d get an extremely effective heater that works the second you turn the engine on.

The Wankel has a basic fuel efficiency problem due to the shape of the chambers formed by the rotor. I can’t verify it, but I’ve heard several times that this is the primary reason it’s use has expanded in the auto industry. Because Wankel type rotaries can be made very light, and vibration free-ish, they are growing in popularity in the small aircraft industry. But for auto makers, fuel efficiency is a major consideration, and Wankels seem to have reached their peak, for the time being.

All engines produce excess heat the moment they’re started. Nobody wants to put an air-to-air heat exchanger in a car because, unlike aircraft, they aren’t inspected and re-certified every year.

As far as rotary engines go, the Wankel is one of many designs. There is a rotary Atkinson cycle engine on the design board that may prove interesting down the road.

And the M1A1 is the least fuel-efficient tracked vehicle in the world. It uses about three times as much fuel by volume as an equivalent piston engine. Now, that’s not really an issue for the US Army cost-wise, but it might be an issue for Joe Q. Motorist.

I assume you mean “hasn’t expanded”, since there was exactly one mass-produced rotary engined car in the 70s, one in the 80s, one in the 90s and one in the noughts. The other problem is that they consume staggering quantities of lubricant. It’s not because of the shape of the chambers; it’s because the fuel is supplied via a hollow in the crankshaft.