Hi, heres a question for you...

[Big Pete]

I will pontificate on engine fundamentals at lunch, when I have time to write a long ( and probably slightly patronising) post on the subject. The short version - 2 stroke or 4 stroke there is no other way with pistons. Technically, 2 strokes are more efficient. More later folks.
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GarageOfPower.co.uk

[Bendy]

Triple word score for 'pontificate'.

[Big Pete]

Bendy - I thank you lol.

right, engine fundamentals part one

piston engines only

engine efficiency is all about compression ratios and upper and lower temperature limits. Trust me on this one as its a pain to explain without going into the gas laws and drawing graphs.

If you to inject a self oxidising fuel in a piston engine at tdc on exhaust (having closed the ex valve first obviously) you will not get a very powerful engine.

This is because the bang is NOT what drives the engine. Heat (and the resultant expansion of the air in the cylinder) is what drives the piston down. If you put a pixie with a box of matches in the cylinder (and insulated it so it wouldn`t lose heat), as the the pixie lit the matches (raising the air temperature in the cylinder) the increasing pressure would force the piston down. If you shove explosives (and very little air) into the cylinder, the only gas available to expand and do useful work is that generated by the decomposition of the explosive (which is not much compared to a cylinder full which is then compressed at tdc).

2-strokes have the potential to be more efficient because they can do this twice as fast as 4-strokes.

If you want a really powerful, high efficiency engine you use a forced induction 2 stroke diesel ( which is at least as complex as a 4 stroke engine). Most really big engines (bulldozers, ships, generators etc) are this type. these engines have an exhaust valve in the head and inlet ports at the bottom of the cylinder. At bdc, the high pressure clean air is blown in the ports, forcing the waste gasses out the open valve. after the valve closes the piston starts to rise, compressing the air. At tdc fuel is injected in the normal manner, whereupon it burns, raising the temperature and pressure and forcing the piston back down. Repeat add infinitum.

As an aside, the blowers originally used on drag cars ("jimmy" blowers) were the scavenge pumps used on GMC 6-series bulldozer engines, which are of the type just described.

Here endeth the lesson, more another time if anybody is interested.
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GarageOfPower.co.uk

[dibbster]

What are the advantages of the rotary engine as used by Norton?
Are their any bike companies that still use it?
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Suzuki RF 600 - The two wheeled Testarossa (Deceased)
Suzuki GSXR - Now stops on a sixpence; SBK3's
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[Superabusa]

Piston engine's are measured by displacement & rotary's are measured by swept area, which is why the Norton's were binned in the end cos basically they were a fair bit bigger area than the bikes that they were racing against.
Also if the engine design was any good as a bike engine do you think Suzuki wouldn't have junked so much R & D? It's only when it's a bigger rotor with larger rotor tips that it becomes more efficient (RX7 & RX8). The Norton Aero engine is a different design again as it spends most of it's time at a constant RPM.
On the subject of the Norton BSB bikes though, didn't they have a different engine from the road bikes too. I'm sure they did. In fact if I remember correctly they even rotated in the opposite direction! As for the road bikes Overweight fuckin jellymolds that even the police found hard to ride.
I know you ain't going to agree with me on this Rot@ry but I couldn't give a flying fuck. I'm an aircraft engineer & I have covered Wankel engines in my training many moons ago, Norton's in fact! Also I'm older than you so screw the patronising bit mate. As for the 3 stroke idea, feck right off, it's still the same s.s.b.b. routine. Even jet engines s.s.b.b. In there own way 2 strokes do too, only from different sides of the piston.
I guess DaFrosty was probably thinking of the fact that the rotor is a 3 sided piece of kit it's a 3 stroke motor. Nice thought, but wrong.
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Karma!! Fuck Karma, I am Satan's little helper.

& I'm considerably faster than yow!

[TheGreatMilen...]

cant be arsed to read the replys was the answer Norton ??? that wasnt that long ago was it like 93 or some such ?????

[Big Pete]

Rotary engines suffer badly because the combustion chambers are long and thin, which means there is lots of surface area to absorb heat (remember- heat is what makes it happen) so they run hot and waste energy. It also limits the compression ratio.

The road bikes also had to burn the oily, hot air that was used to cool the rotors, hot air is less dense, so less power and the oil pormotes detonation. There are also lots of problems with rotor sealing and lubrication. The upside is that they can be cheap, simple and light which is why they are used in things like target drones where some of the dissadvantages are not such an issue.
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Trust me, I`m an engineer
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[Shade_BW]

Hi grav!!

[Sadie]

[Shade_BW]

[Mr Pants!]

Mr W@nkle, I do recall those days, although I am only 34 years of old age. I know of all sorts of classic bikes as my uncle is one of the biggest dealers in them.

I will have to ask him about the Norton Rotary days......

He still chuckles at my plastic rocket, I my bike will never end up a classic as it would have probably disintegrated by then.....
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Mr Pants! (Alex or Al)
Its better to burn out, than to fade away....

[Kickstart]

Hi

I do remember the Norton Rotaries, and remember seeing them race at the GP at Donington as a special one off (certainly raised a few cheers).

An engines capacity is measured as its swept volume, and it is just as easy to measure that for a rotary as for a normal piston engine. The problem is that a rotary engine has, effectively, 3 chambers sweeping the same volume at the same time so you can argue away about the effective volume when compared to a piston engine. For example if you say that a 2 stroke can have half the capacity of a 4 stroke as double the number of strokes are useful, then you could treat the rotary as having a capacity of a 4 stroke engine of 6 times the capacity.

From memory by the international rules the 588cc Norton was actually an 1176 (double the swept voume), but the UK rules were fudged to allow them to race.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Demonic69]

Anything a bit more challenging W@nkel?
And Norton were onto a winner with the F1, if only they'd mass produced it a little earlier they'd still be a major player on the pocket-rocket scene.
And are you really the Wankel who created the Rotary engine used in the RX7? Or just like the name?
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Back on a Blade. Just feels so right.

[W@nkel]

[Dr Nick]

[jayluvmito]

damn, i never seen them norton f1's before....

detect the sarcasim ther.....
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one day...

[Kickstart]

The F1 was a barely deveoped limited production bike with hideously dirty exhaust emisions (couldn't be sold in Germany because of this).

All rotaries have a very poor combustion chamber shape.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Kickstart]

[W@nkel]

[Ava_Banana]

At 37 I must confess I had no real interest in bikes until a few years ago, but now am very interested.

From a technical point of view I have always been interested in the Wankel engine (well, rotary engines). It constantly amazes me how "theoretically" inefficient the process of "converting reciprocal to rotary energy/force" is.

Mazda certainly do well with them.

[MarJay]

I haven't clicked on the link or looked at the rest of the thread but I can tell you that it was Norton, with a 1355 (or 599 depending on who you are) cc Wankel engined bike.

They make a heck of a noise!

Right, now I can read the rest of the thread!
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[W@nkel]

[MarJay]

Right read the thread, very interesting. However I have to ask why there is so much aggression form Superabusa... he who is without fault etc etc.

[W@nkel]

[W@nkel]

Lets see if i can put a photo on here... Norton F1 'Sport'
Note the 'Overweight fuckin jellymold that even the police found hard to ride' in the background.
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Click here for my Norton Wankel motorcycles web page