Torque vs Horsepower

[MrDudeMan]

Originally posted by: kevinthenerd

Originally posted by: 91TTZ

Originally posted by: kevinthenerd

You don't need an engine lift to work on a Wankel. They're extremely light. A stock two-rotor from a first-gen (which had a carburetor and was in a crappy state of tune) gave over 100hp, so 300hp from a six-rotor is the bare minimum starting point. In a Wankel you have all different porting options ranging from stock to race, including J porting, bridge porting, and peripheral porting. You can order custom race engines and whatnot from Pineapple Racing, and perhaps on their website, you can get an idea of what that engine can do before you raise the ignorant flag.

Don't forget about the Mazda 787B. It used basically a Cosmo engine (3-rotor) to develop so much horsepower that it was quickly banned.

The wankel is not that light. You still need an engine lift to work on it, unless you can curl 250-300 lbs while you unbolt it.

It's also a horribly inefficient engine. People that are amazed by them often don't just understand them. They are not as reliable as a piston engine and get worse gas mileage for the same power produced.

Most of the fools that argue with me about this believe that the rotors in those engines spin at 8,000+ rpms. They just don't understand how they work.

...snipped useless code...

What the hell did that prove? That doesn't mean you understand how it works. It just means you can program in basic (haha...).

 

[kevinthenerd]

Originally posted by: MrDudeMan

Originally posted by: kevinthenerd

Originally posted by: 91TTZ

Originally posted by: kevinthenerd

You don't need an engine lift to work on a Wankel. They're extremely light. A stock two-rotor from a first-gen (which had a carburetor and was in a crappy state of tune) gave over 100hp, so 300hp from a six-rotor is the bare minimum starting point. In a Wankel you have all different porting options ranging from stock to race, including J porting, bridge porting, and peripheral porting. You can order custom race engines and whatnot from Pineapple Racing, and perhaps on their website, you can get an idea of what that engine can do before you raise the ignorant flag.

Don't forget about the Mazda 787B. It used basically a Cosmo engine (3-rotor) to develop so much horsepower that it was quickly banned.

The wankel is not that light. You still need an engine lift to work on it, unless you can curl 250-300 lbs while you unbolt it.

It's also a horribly inefficient engine. People that are amazed by them often don't just understand them. They are not as reliable as a piston engine and get worse gas mileage for the same power produced.

Most of the fools that argue with me about this believe that the rotors in those engines spin at 8,000+ rpms. They just don't understand how they work.

...snipped useless code...

What the hell did that prove? That doesn't mean you understand how it works. It just means you can program in basic (haha...).

First of all, I'm a MECHANICAL engineering major. I'm not half the computer guy I used to be. It's perfectly acceptable that BASIC is my preferred language. I can read and write in other languages, but BASIC is my favorite. I know it sucks, but it's not worth my time becoming an uber geek and acquiring that level of fluency in another language because I'm not going to be a programmer for the rest of my life.

That code was just a start. Later I'll add Monte Carlo integration routines to determine the chamber volume with respect to time for comparison with a piston engine with a given rod-to-stroke ratio. I'll change the shape of the rotor to more closely resemble an actual Wankel rotor. Eventually I'll go 3-D and add the eccentric shaft and housing and apex seals.

The most difficult aspects of my model are going to involve turbulent CFD, especially in the combustion model. Engineers don't know how to properly model turbulent combustion yet, and laminar flame modeling leaves results that are at minimum 10% off.

I could tell you how a Wankel basically works, but I'd invariably end up reciting a summary of the Wikipedia article.

http://en.wikipedia.org/wiki/Wankel_rotary_engine

Some basic rebuilding information can be found at...

http://www.rebuildingrotaryengines.com/

A basic understanding of internal combustion engines (assuming a working background in engineering thermodynamics) can be found in the industry-standard text...

Internal Combustion Engine Fundamentals by John B Heywood
http://www.amazon.com/Internal...qid=1185241458&sr=11-1

What do you want from me? Believe what you want about my credentials.

Edit/PS:

There are 168 hours in a week and just over 52 of those in a year. I'll only get between 24 and 120 of those for my total lifetime... 24 if I die now and 120 if I end up close to a world record. No matter how you slice it, life is short. In my finite amount of time on earth, I hope that I won't have as a claim to fame that I could fit the credibility requirements of everyone I met. If I tried to do that throughout life I'd always end up paying for it dearly by spending opportunities elsewhere.

 

[kevinthenerd]

Originally posted by: Zenmervolt

Originally posted by: kevinthenerd

Originally posted by: Zenmervolt

Originally posted by: kevinthenerd
I never said that the Wankel was the ultimate solution for an econobox, but it's hard to beat it as a sports car or race car engine.

As long as you don't care about fuel efficiency at all, they're great, yes. Unfortunately, when you have to stop twice during a race where everyone else only has to stop once, it's really, really hard to win.

They're interesting engines to be sure, but there's just something wrong to me about any engine that intentionally burns oil. (The advantage for things like chainsaws is that being two-cycle allows the engine to remain lubricated regardless of orientation without needing some sort of quasi-miracle oil sump setup.) The Wankel burns more fuel to make the same power and it produces greater amounts of emissions. From an engineering standpoint it's a cool toy, from an efficiency standpoint it's a false-start.

ZV

In mass production, I believe the Wankel could be a cheap alternative for small engines like those. Despite the poor emissions, I think you'd still outdo the emissions of a 2-stroke, but that's honestly just speculation. Fitting plugs into the tiny chambers could be a problem without expensive custom plugs. (A Wankel relies heavily on kernel formation from multiple plugs because the flame front travels too slowly in its pancake combustion chamber.)

I dunno, you'd still need a sump of some sort, unlike a 2-cycle. Unless you built some sort of 2-cycle Wankel, in which case you're back to square 1 on the emissions.

ZV

There would be absolutely no difference in the lubrication technique of a 4-stroke Wankel versus a 2-stroke Wankel. The oil comes through the intake either way. The challenge still is lubrication of the timing gear and eccentric shaft, but I wonder whether something like that could be worked out by pumping the fuel through there before it gets to the engine just as it is in a 2-stroke piston engine.

 

[91TTZ]

Originally posted by: kevinthenerd

There would be absolutely no difference in the lubrication technique of a 4-stroke Wankel versus a 2-stroke Wankel. The oil comes through the intake either way.

What do you mean by that?

 

[Zenmervolt]

Originally posted by: 91TTZ

Originally posted by: kevinthenerd

There would be absolutely no difference in the lubrication technique of a 4-stroke Wankel versus a 2-stroke Wankel. The oil comes through the intake either way.

What do you mean by that?

He means that all Wankel engines are oil burners by design. This is, unfortunately, true.

ZV

 

[Demon-Xanth]

In a 4 cycle piston engine the cylinders are lubricated by oil seperated by three rings. They're needed to maintain compression. A wankel's apex seals have the problem of an air fuel mixture on both sides. So to be lubricated, there must be an air-oil-fuel mixutre, just like a two stroke (which often has the air-oil-fuel mixture on both the top and bottom of the piston).

 

[91TTZ]

Originally posted by: Zenmervolt

Originally posted by: 91TTZ

Originally posted by: kevinthenerd

There would be absolutely no difference in the lubrication technique of a 4-stroke Wankel versus a 2-stroke Wankel. The oil comes through the intake either way.

What do you mean by that?

He means that all Wankel engines are oil burners by design. This is, unfortunately, true.

ZV

I know they're oil burners, but what does he mean by the oil coming through the intake?

 

[kevinthenerd]

Originally posted by: 91TTZ

Originally posted by: Zenmervolt

Originally posted by: 91TTZ

Originally posted by: kevinthenerd

There would be absolutely no difference in the lubrication technique of a 4-stroke Wankel versus a 2-stroke Wankel. The oil comes through the intake either way.

What do you mean by that?

He means that all Wankel engines are oil burners by design. This is, unfortunately, true.

ZV

I know they're oil burners, but what does he mean by the oil coming through the intake?

The oil enters the motor along the same route through which fuel and air enter: through the intake port of the motor. When people hear "intake" they typically think of a fat hose with a filter on one end, but that's not exactly a rigorous way of thinking about what "intake" really means.