This might interest Oerdin only...

[Spec]

Originally posted by Provost Harrison
Still sounds like a pointless extravagance to me...

What? Startrek?

Every car would be rotary powered if it had benefited from the piston engine's years of evolution. A rotary engine has only 3 moving parts, 2 rotors and a shaft, a regular 6 piston engine has 196 moving parts...Which would you choose for reliability if both had had 100 years of reseach over 20 major companies. Think logicly now.

Spec.

[Provost Harrison]

Well the problem is, practically, few people would be prepared to take that 100 year step back in terms of reliability and economy...

[Provost Harrison]

I'm sure it has niche applications, but I am certainly not sold on the idea - it fails on what I consider to be the practical aspects of a modern car.

[Spec]

Rotary engines are used a whole lot. Its mostly used in boats, generators, planes and lawn mowers. The RX series is really the only market car in which its used.

Another advantage is that is has no negative energy, unlike a piston that is thrown back and forth, the rotor spins and keeps on spinning, thus, why it can reach such high RPMs. 22000 rpm is the red line in the Lemans 787B.

Spec.

[Dinner]

Re: Re: Re: NASCAR

Originally posted by pchang
If you have a big mass spinning along your axis of motion, it helps you turn in one direction, but makes it harder to turn in the other direction (try to remember the right hand rule from your early physics days). The old biplanes in WWI had rotary engines oriented such that they could make snap turns to the left, but had a hard time turning right.

As stated earlier, the balance that out by having twin rotors which are 180 degrees out of sync with each other. That's the same way a piston powered engine balances out vibrations.

[Dinner]

Originally posted by Spec
How can WW1 plains have rotary engine when it was conceived in 1954? This one:


Which is an RX7 engine. Well, almost, it's missing a spark plug and the intake port is on the side.


You must be talking about another rotary engine, like this one maybe?



Spec.

Spec, the top one is a rotary engine while the second is a radial engine. Huge difference between the two.

[Dinner]

This is a radial engine commonly used in airplanes. Radials had larger surface area so that an air cooled engine could running at higher speeds/temperatures and still cool effectively. That was perfect for planes.

[pchang]

Re: Re: Re: Re: NASCAR

Originally posted by Oerdin


As stated earlier, the balance that out by having twin rotors which are 180 degrees out of sync with each other. That's the same way a piston powered engine balances out vibrations.

Yes, I equated rotary with radial. In either case, you have a decent mass spinning. Naturally for a car that needs to turn left AND right, you would want a contra-rotating design. However, in NASCAR you only need to turn left, so why not have an unbalanced design. With the help of the angular momentum, you should be able to take turns at higher speeds and would have a small advantage over normal engines. I'm told that in NASCAR, all you need is a small advantage to go from the middle of the pack to champion.

[ColdWizard]

NASCAR is far too restrictive to allow such things as rotary engines.

[Spec]

Originally posted by Oerdin


Spec, the top one is a rotary engine while the second is a radial engine. Huge difference between the two.

Oh I know, it's just that it is often mistaken for a rotary engine (w ankel). Just type rotary engine in google in the image option and you get a radial engine.

Spec.

[Spec]

Re: Re: Re: Re: Re: NASCAR

Originally posted by pchang


Yes, I equated rotary with radial. In either case, you have a decent mass spinning. Naturally for a car that needs to turn left AND right, you would want a contra-rotating design. However, in NASCAR you only need to turn left, so why not have an unbalanced design.

The car would jump up and down, thus losing traction and under steering...imo. That's why rotary engines have counter-weights on the flywheel. Otherwise, the engine mounts would just shatter.

Spec.

[pchang]

by "unbalanced", I meant both all rotors would spin in the same direction. I did not mean to remove the counter balancing fly weights. Thus, the car would not jump up and down.

[Dinner]

Originally posted by Spec
Rotary engines are used a whole lot. Its mostly used in boats, generators, planes and lawn mowers. The RX series is really the only market car in which its used.

Another advantage is that is has no negative energy, unlike a piston that is thrown back and forth, the rotor spins and keeps on spinning, thus, why it can reach such high RPMs. 22000 rpm is the red line in the Lemans 787B.

Spec.

The Polish car company NSU (now owned by Daiwoo which itself is partially owned by GM) built rotory powered cars in the 1960's and 1970's while Mazda built the Cosmo in 1968 and a series of sedans and even trucks with rotory engines in the 1970's. Those early rotary engines suffered from bad apex seals which often caused the engines to die after a few thousand miles.

Luckly, Mazda has had three more generations of rotary engines since then and so the modern ones are light years ahead of the ones from the 60's and 70's.

[Spec]

Originally posted by pchang
by "unbalanced", I meant both all rotors would spin in the same direction. I did not mean to remove the counter balancing fly weights. Thus, the car would not jump up and down.

Yes it would. 2 rotors going up at the same time would make the car jump. The counter weight helps balance the engine when 2 rotors are turning 180 degrees off. Imagine if you adjust them at the same degree, the engine mounts would just shatter.

Seriously.

Spec.

[Spec]

Originally posted by Oerdin


The Polish car company NSU (now owned by Daiwoo which itself is partially owned by GM) built rotory powered cars in the 1960's and 1970's while Mazda built the Cosmo in 1968 and a series of sedans and even trucks with rotory engines in the 1970's. Those early rotary engines suffered from bad apex seals which often caused the engines to die after a few thousand miles.

Luckly, Mazda has had three more generations of rotary engines since then and so the modern ones are light years ahead of the ones from the 60's and 70's.

They now use ceramic apex seals, which reduce engine wear and are a lot harder to break. Before, up to the 3rd gen RX7 they used metal Apex seals, so friction was metal to metal. That's why a rotary engine burns oil like a 2 cycle engine. My rx7 is modified to run with gas and oil mixture. Meaning that everytime I go fill up, I have to put 6oz of 2 cycle engine oil for 20l of gas.

Much better for the engine and much cleaner for the environment.

That's how mazda wanted it to work but no one would of bought a car where you have to make a mix everytime you go fill up.

Spec.