engine designs-what the future holds - concrete

I recently read a small article in a magazine about the w***el engine. A rotary engine with fewer moving parts than a normal piston engine.

At the time it was seen as the future and a major advancement to the internal combustion engine. What happened? I know that Mazda make a car with a rotary engine, but if it had such potential why was it not truly developed on a larger scale? I am not a mechanical engineer but the concept sounds very good. Any comments?

Cheers Concrete

engine designs-what the future holds - John F

Those of us old enough remember the NSU Ro80 as prematurely wearing out the rotor tips and lousy fuel economy. Thanks for reminding me about this fascinating engine (excellent piece in Wiki). Seems it might have an ideal future as a small light range extender for hybrids.

engine designs-what the future holds - brum

Mazda has tried to perserve with the w***el engine for many years but have never managed to overcome the fundamental design problem of sealing the rotor reliably without wearing seals. Its a design that is novel but fundamentally limited in that it cannot acheive high compression or efficiency. It is a high oil burner.

It has no future apart from a chapter in engine design history.

NSU who pioneered it became Audi, who saw it was a dead end.

engine designs-what the future holds - Engineer Andy

At present Mazda aren't selling (presumably not making either) any rotary engined car (the last being the '4-seater' [barely, at the cost of a lot of boot space] RX-8) at present, though a successor may be in the pipeline. It had a 1.3 ltr engine, developing between 200-240 bhp - the problems it suffered from were:

  1. Low torque - you had to rev the proverbial nuts off it (even more than a VVTi type engine) to get all that power down, making it noisy like a vacuum cleaner - not a cruiser or an everyday car, more a weekend car for a thrash.
  2. Very poor fuel economy and high CO2 emissions - see the HJ review.
  3. Hates short journeys from cold (far more than diesels) which can ruin the engine, CAT etc in no time. Too many buyers were either ignorant of this (they didn't do their homework) or were duped by sellers, including I suspect the occasional main dealer.

Shame really it never took off - I personally liked the styling, both inside and out, it handled very well too. If they'd had made it a foot longer to get over 300 lts of boot space and ok-ish leg room in the back, plus either the V6 or better still the 2.3 turbo out of the 3 and 5's MPS models, they'd be on to a winner - it would've been near the top of my list.

engine designs-what the future holds - bathtub tom

I thought Mazda had largely cured the rotor tip wear problem. I understand it's basically a 2-stroke as the rotor tips have to be lubricated somehow.

Ford went down the path of a 3 cylinder 2-stroke a few years ago with a firm in Australia, but it came to nothing. Largely I believe due to exhaust emissions. I loved the sound of those old Saab (and Wartburg) 2-strokes. Now where did I put that can of Castrol R?

engine designs-what the future holds - craig-pd130

As other said above, most of the major motor manufacturers experimented with rotary engines in the 60s and 70s, from Mercedes to Citroen to American manufacturers, to Suzuki, Yamaha and Norton/Villiers/Triumph.

The rotor tip sealing problems that plagued early designs were largely fixed, but the fuel crisis of the 70s and ever-tightening emissions regimes made it uneconomical for most makers to pursue rotary power further, apart from Mazda who stuck doggedly with it.

It's a pity because the design has advantages in that it spins smoothly, rather than thrusting pistons from standstill to standstill. But they burn oil, and are harder to meter fuel into.

Fixing the fundamental problems basically bankrupted NSU and nearly took Suzuki to the wall, too.

engine designs-what the future holds - RT

The big problem with w***el engines is that the inlet/exhaust "valve" timing is controlled simply by rotor position, much the same as two-strokes were dependent on piston position.

As material technology improves, the use of micro-turbines as range extenders will be explored by more car makers - gas turbines needs constant speeds which lends itself to range extending rather than primary power source and the lack of pumping losses will give better economy than reciprocating engines.

Edited by RT on 12/09/2016 at 23:25

engine designs-what the future holds - concrete

Marvellous stuff. I do remember the Ro80 and how it was hailed at the time as a revolution (pardon the pun) in engine design. From the information given here it seems clear why the design has not been developed. I do wonder though if sometime in the future the problems will be solved to create an efficient rotary engine.

Thanks for all the great comments. Cheers Concrete

engine designs-what the future holds - craig-pd130

As material technology improves, the use of micro-turbines as range extenders will be explored by more car makers - gas turbines needs constant speeds which lends itself to range extending rather than primary power source and the lack of pumping losses will give better economy than reciprocating engines.

Like the Jaguar prototype of a few years ago, which had a briefcase-sized turbine. Finally, we might get to have jet cars! :)

engine designs-what the future holds - oldroverboy.

en.wikipedia.org/wiki/Rover_JET1

Rover did it before i was born..

news.bbc.co.uk/onthisday/hi/dates/stories/march/8/...m

Edited by oldroverboy. on 13/09/2016 at 21:24

engine designs-what the future holds - oldroverboy.

edit won't work so

How I wish that king and wilks were here to use cad/cam and modern manufacturing techniques.

en.wikipedia.org/wiki/Rover-BRM

engine designs-what the future holds - RT

en.wikipedia.org/wiki/Rover_JET1

Rover did it before i was born..

They never even got close to solving the fuel consumption issue

 

Value my car