“Inside-out Wankel” rotary engine delivers 5X the power of a diesel

Post by qup » Wed, Apr 05, 2023, 8:46 PM UTC

0cf8612b2e1e wrote: post #129

bluGill wrote: post #97

Earlier quoted context omitted.

Every motorcycle mechanic I've seen has a sign in the shop: speed costs money, how fast do you want to go. That sign isn't referring to the costs to modify an engine to go faster so much as the cost to constantly rebuild the engine after they modify it to go fast. I've seen two identical engines, one rebuilt to stock and one rebuilt to max speed - the cost for both rebuild jobs was about the same (the parts for speed…

What is done to modify an engine for speed? What kind of improvement can be seen for speed (accelerates XX faster? YY higher top speed)?

Post by lb1lf » Wed, Apr 05, 2023, 8:51 PM UTC

themaninthedark wrote: post #121

Cthulhu_ wrote: post #106

Earlier quoted context omitted.

I think a lot of commenters in articles like this will only think about automotive as a use case for alternative engine designs. I'm reminded of a linear piston engine (iirc two pistons that just go back and forth without their motion being translated into rotation; one where they were side-by-side moving alternately, the other one where they'd actually move towards each other and share a combustion chamber). The use…

My first thought went to cargo ships. They require huge motors, so I imagine that if you can keep or gain performance while reducing size they would be very interested.

Post by shortsightedsid » Wed, Apr 05, 2023, 9:02 PM UTC

red-iron-pine wrote: post #85

astral303 wrote: post #74

Earlier quoted context omitted.

rotary engines do not really scream at peak power... this is why Mazda has plans to use rotary at peak power to generate electricity for their hybrid EVs. re 20 years to make a new engine point, compare investment $ in traditional ICE across the car industry vs investment $ into rotary or other alternative engines (the former is order of magnitudes more)

Mazda still holding on to those rotary engines, eh? Still, call my interest piqued. I'll keep an eye out for their Wankel-EVs

Post by codeflo » Wed, Apr 05, 2023, 9:08 PM UTC

mcronce wrote: post #142

codeflo wrote: post #122

Earlier quoted context omitted.

> Besides, nobody is calculating this, they are measuring and that is just a matter of what label you put on the dial. That's why I asked about engineering, not driving. Nobody converts torque to power etc.?

Torque to power is just (torque * RPM) / (some constant depending on the units inolved). With ft-lbs and horsepower, that constant is 5252; with N-m and kW, it's 9549. The only thing that changes is the constant.

Post by mcronce » Wed, Apr 05, 2023, 9:34 PM UTC

raketenolli wrote: post #148

mcronce wrote: post #142

Earlier quoted context omitted.

Torque to power is just (torque * RPM) / (some constant depending on the units inolved). With ft-lbs and horsepower, that constant is 5252; with N-m and kW, it's 9549. The only thing that changes is the constant.

No, power is just torque times angular velocity. No constants involved.