rotary vs. cylinders

[rice(er)]

which is better? disadvantages and advantages? whats the difference besides that the rotarty spins and cylinders go up and down or back and forth? your experiences with them? which do you prefer? anything else?

[Muscletang]

Rotary

PRO: spins to high RPMs, engine can handle high RPMs and gets to them quickly, makes lots of power for a rather small engine

CON: it has almost NO torque, nobody knows much about them so they're hard to service, known to break down after 50,000 miles

I'll let you make the choice.

[christophv]

rotary engine have a bad mpg efficiency, and as being said, they aren't very reliable.

a big pro:
their layout allows very smooth revolutions and no "loss of power", as a cylinder engine loses much power due to lateral momentum forces (not sure of my language here)

for the torque thing -

a rotary engine doesn't need torque, because ist just a totally different engine layout.
cylinder engines gain their hp performance from torque, rotary engines from their quick response and high RPM.
they just use gears with very long ratios, where torque isn't necessary.

but I think, when rotaries want to compete with cylinders, they need to get rid of their reliability issue (which is possible with new materials such as high-tech ceramics) and rev even higher until like 12-14k RPM so they have a real advance.

[mason_RsX]

Another huge benefit to the rotary engine is that it weighs alot less than a regular cylinder engine. This makes it alot easier to achieve 50-50 weight distribution

[kman10587]

Another huge benefit to the rotary engine is that it weighs alot less than a regular cylinder engine. This makes it alot easier to achieve 50-50 weight distribution

Well, this is a bit misleading. In order for it to make big power, you pretty much need to turbocharge and intercool a rotary engine. With the added weight of those parts, the complete package will probably weigh about the same as a piston engine that is comparable in power. Look at the 13B-REW vs. LT1: they both make about 280 horsepower, and they both weigh about the same. The difference is that the 13B uses high revs and tight gearing to keep in its powerband, while the LT1 has a wider powerband due to its large torque output, and wide gearing to maximize its top-end acceleration. Even smaller piston engines, like the EJ20 and 4G63, make considerably more torque than the 13B or Renesis. They are both good designs when it comes to power-to-weight, so it really comes down to what kind of driving experience you want: high revs and good weight balancing, or a wide range of power and proven reliability.

[NISSANSPDR]

I'd rather go w/pistons...personally

[rice(er)]

coo, thanks

[Pavlo]

Could always do a search...http://www.automotiveforums.com/vbul...rotary+pistons .
I would take a well built car, no matter what the engine is. Another rotary adventage is very small amount of rotating parts, therefore less things to break.