internal-combustion engine

[ZokesPro]

Originally posted by Gurm
The rotary engine is one of the finest automotive inventions ever.

I HAVE SPOKEN.

- Gurm

Aside from suspension and brakes, I'd have to agree.

[GNEP]

- And pneumatic tyres!

[MultimediaMan]

The rotary engine is one of the finest automotive inventions ever.

You people forgot Norton and Suzuki both produced Wankels for Motorcycles. O.S. still makes a Wankel for Model Airplanes.

The Wankel is a great engine, but as far as it being the "best" there are some other things to consider:

1. They are expensive to produce.
2. They have to use roller bearings for the Rotor and Crankshaft instead of plain bearings - this shortens longevity.
3. They have to use a pressed-together crankshaft due to how the rotor is made - this increases manufacturing costs and is a potential point of failure if the crank were ever to shift out of true.
4. The Rotors are still made of iron - experiments continue to make an aluminum rotor with super alloy tips (the tips of the rotor are the sealing surface for compression).
6. Emissions from Wankels can be quite high, especially those with worn rotor and case tips.
5. No one is quite sure how best to determine their displacement exactly - which hurts their development for racing. There are several solutions for determining a Wankel's actual per-rotor displacement.

[az]

There are more Wankels still produced than one might think, not only for cars.

The RX-8's RENESIS Wankel is quite interesting, as is the whole car It fits the EURO-4 emission norm.

AZ

[GNEP]

Off Topic:

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And what about external combustion engines, eh? I particularly like that Stirling cycle - but not many people seem to make use of it, as a heat pump or an engine...

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[dave m]

barely on topic

In January, fed up with commuting to work with a 2.5 litre 24 valve V6 21mpg car, I bought a 50cc moped/scooter that does 100mpg.

In order for me to drive it without a motorcycle licence it has been restricted (baffles in the exhaust) so it can only do 30mph. Clearly it is capable of much more, it champs at the bit as you approach 30 mph, and I understand that if you tinker with the engine, baffles, gearbox etc (invalidating warranty, insurance, licence to drive and everything else) it is capable of doing 55-60 mph and accelerating like mad... all from a 50cc engine. I'm still bowled over by it.

Imagine my surprise when I bought a push along petrol lawn mower yesterday, got it home and found it had a 147cc engine.

Is that silly, or is this a brute/grunt/immoveable/object/ force needed behind the blade thing?

Edit: can't spell blade

[MultimediaMan]

Hell...in the day at Motorcycle Mechanics Institute we routinely took a 6 Horsepower 50cc Two Stroke (Yamaha YSR50) and bumped them to over 18 Horsepower. Not bad for an aircooled engine.

We took a watercooled Honda NS-50 Engine, threw in some CR-50 dirtbike parts, bigger carburetor (24mm Flat Slide I think) and an exhaust (Custom made) and had easily 20 horsepower of streetable power.

Not to be outdone, a couple instructors took a two cylinder Yamaha RD125 Engine, flipped the cylinders around (Exhausts facing rearward), and proceeded to stuff it into a YSR Chassis: 37 Horsepower: 118 MPH on a 44 inch Wheelbase is TOUCHY.