Rotary Engines.....

[Jiff Lemon]

For all who wondered WTF?

http://www.mazdarx8.co.uk/rotary/rot...ocumentid=1331

Simple little animation showing the wonders of the Rotary.

[TiG]

Okay, understand the principle, but the most important thing is WHY?, what advantages and disadvantages does this have?.

It appears to me that it would cost more to build this engine, boaring(sp?) of the engine would be more expensive?.

Interested to know the WHY here

TiG

(and i have read the benefits on the web site, i just don't trust all of it)

[5lab]

a 1.3 litre rotery is as powerful as a 2.6 normal (roughly). so weight is probably saved

[TiG]

Then why don't we all have rotary engines?

TiG

[Nick]

Off the top of my head Tig...

Lighter weight
Because there is no need for pistons, connecting rods or a crankshaft, the main engine block of the rotary engine is correspondingly smaller and therefore lighter in weight with better handling and performance.

Smaller size
Proportional to its output, the rotary engine is substantially smaller in size than a conventional engine. The new RENESIS is about the same size as a small four-cylinder in-line engine. The rotary engine’s small size is not only beneficial with regard to weight, but also allows improved handling, optimal positioning of the drivetrain and increased space to be given over to driver and passenger comfort.

Lower vibration
All the parts in a rotary engine spin continuously in one direction, rather than violently changing directions like the pistons in a conventional engine. Rotary engines are also internally balanced minimising vibration levels.

Higher power
A rotary engine’s power delivery is smoother. Because each combustion event lasts through 90 degrees of the rotor's rotation, and the output shaft spins three revolutions for each revolution of the rotor, therefore each combustion event lasts through 270 degrees of the output shaft's rotation. This means that a single-rotor engine delivers power for three-quarters of each revolution of the output shaft. Compared to a single cylinder piston engine, in which power is delievered to only a quarter of each revolution of the output shaft.

Higher reliability
The rotary engine has far fewer moving parts than a comparable four-stroke piston engine. A two-rotor rotary engine has three main moving parts: the two rotors and the output shaft. Even the simplest four-cylinder piston engine has at least 40 moving parts, including pistons, connecting rods, camshaft, valves, valve springs, rockers, timing belt, timing gears and crankshaft.


yep... that's about it...

[TiG]

i told you i read the web site

Answer the next question then - if they are sooo good why don't we all have them?

TiG

[Skii]

Fuel economy I think - rotary engines are thursty.

[Jiff Lemon]

Initally there was a problem with the Rotor tips wearing out.
Wasn't helped by owners removing all the rev-limiting features of the early engines.

Mazda have (apparrently) now resolved the issue and decent reliablilty.
Why's it not in every car?
Cost probably.
Peoples inbred fear based on the past.
Also, rotarys suffer from lower torque figures (hence the turbo).

[TiG]

Yer see what you mean.....

211Nm @ 5500rpm for the higher power rotary....

Combined 25.2mpg
extra urban 32.5mpg
urban 18.1mpg

Cost - anyway to find out how much they cost?...

TiG

[5lab]

they're not overly more expensive than a normal engine - based on mazdas with rotery engines arnt overly more expensive than normal rivals - but they do have a drinking problem.

[3Dfx]

Ahhh nice Wankel

lol

[Lowe]

Rotary engine are also patented and can only be produced by Mazda. That's why you don't see many of em.

[Moby-Dick]

Originally posted by Lowe
Rotary engine are also patented and can only be produced by Mazda. That's why you don't see many of em.

except on Nortons

[Tumble]

yeah Nortons... there were a couple at the TT this year.... phwoooaor.. they were revving them up for the press and they sounded magnificent - just like a HUUUUGE turbo... made me

[Rave]

Originally posted by Moby-Dick
except on Nortons

.....and NSUs. I can't believe they are patented, they've been around since the 60s at least, and a patent lasts 20 years. Mazda may have patented the technology that makes them reliable.

There's an RX7 I sometimes see cruising around my area, with a full bodykit, spoiler etc.....and a big bore exhaust, which makes it sound like a Nova with a blowing gasket.

Rich :¬)

[unrealrocks]

Originally posted by Tumble
yeah Nortons... there were a couple at the TT this year.... phwoooaor.. they were revving them up for the press and they sounded magnificent - just like a HUUUUGE turbo... made me

I love rotary engine sound ... there SOOOO smooth and with a good turbo sound brill!

I remember reading an explanation in a mag a few months back, didn't know Mazda patented it tho - I've seen a Supra have one of these in (UK version as well, quite a rare thing on its own, lol)!