[enkeivette]

Originally Posted by SeanPlunk

I actually don't agree - I think the rotary is cool. You can get a lot of power out of a little displacement and you can rev the hell out of them.

I agree they do have some obvious downsides though. They get marginal gas mileage at best and replacing seals every 40k miles is a bummer.

40K miles? Where the hell did that number come from? The 16 year old you knew who didn't know that he had to add oil to his rotary constantly and abused the shit out of it?

Badass, didn't a rotary win Le Mans? The answer... uh, yeah. The rotary is an awesome engine, and a rotor doesn't need to change direction like a piston. So the motor is more balanced and there is more rev potential.

Yeah they burn oil and yeah they suck gas, but from a performance perspective they are great. So admittedly it might not be the best motor for grandma's econo car, but who cares?

[enkeivette]

As far as the 3 chambers having 1.3L/2 each, one chamber is to suck the air in, the 2nd is for combustion and the 3rd is for exhaust. So why would you count more than one? I don't count my combustion chamber 3 times, or even 4 times, why should they?

[BADDASSC6]

Originally Posted by enkeivette

As far as the 3 chambers having 1.3L each, one chamber is to suck the air in, the 2nd is for combustion and the 3rd is for exhaust. So why would you count more than one? I don't count my combustion chamber 3 times, or even 4 times, why should they?

Because each chamber sucks in, combust, and exhaust every revolution. If we only counted the combustion chambers then my vette is only three liters.

[enkeivette]

Originally Posted by BADDASSC6

Because each chamber sucks in, combust, and exhaust every revolution. If we only counted the combustion chambers then my vette is only three liters.

But you only do count one compression chamber in your motor. If you counted them separately like youre trying to do in the rotary you would have a 24L engine.

And if you want to count all of the strokes of the rotary shouldn't it be 3.9L?

The difference is our motors use the same chamber for all strokes, rotaries don't. So how do you say what's fair?

[BADDASSC6]

Originally Posted by enkeivette

But you only do count one compression chamber in your motor. If you counted them separately like youre trying to do in the rotary you would have a 24L engine.

No way that is flat out wrong dude. In ALL OTHER MOTORS they determine the displacement by multiplying the stroke time the area over the piston time the number of cylinders. It's the formula followed by all other motors. Following this rule the RX-7 has a 7.8L motor. Which is funny because a RX-8 gets worse mileage than a 7.0 L z06.

[enkeivette]

Here's a better way to think about it. At best, one of your cylinders can fill 6/8L worth of air/gas. You don't count any certain stroke, just the fact that your cylinder at one point in time can fill only 6/8L of air/gas.

A rotary, although it jumps from chamber to chamber unlike your engine (which uses the same chamber for all strokes) can only fill 1.3L of air/gas. On the next stroke, it's moving 1.3L of that same air/gas, but in a different chamber. But while the air/gas has moved into the 2nd chamber, the 1st and 3rd chambers are not operating. Thus, it would be unfair to count them.

What's important here, is how much air/gas the motor can move in one revolution.

http://auto.howstuffworks.com/rotary-engine4.htm

[BADDASSC6]

Originally Posted by enkeivette

Here's a better way to think about it. At best, one of your cylinders can fill 6/8L worth of air/gas. You don't count any certain stroke, just the fact that your cylinder at one point in time can fill only 6/8L of air/gas.

A rotary, although it jumps from chamber to chamber unlike your engine (which uses the same chamber for all strokes) can only fill 1.3L of air/gas. On the next stroke, it's moving 1.3L of that same air/gas, but in a different chamber. But while the air/gas has moved into the 2nd chamber, the 1st and 3rd chambers are not operating. Thus, it would be unfair to count them.

What's important here, is how much air/gas the motor can move in one revolution.

http://auto.howstuffworks.com/rotary-engine4.htm

No way. Again NO WAY! Each cylinder in my car is only ~.75 liters not 6 or 8 liters. Only half the cylinders fire per revolution. On a rotary EACH LOBE creates CHAMBER that measures 1.3L, there are THREE CHAMBERS PER LOBE (look at your simple little drawing), all of them conduct a complete intake, compression and exhaust cycle.

Dude, you just proved my point:

"If whats improtant is how much air/gas a motor can move per revolution" then I'm rocking a 3 liter and a RX-7 is rocking a 7.8 liter. Now I will run ANY NA rotoray.

[SeanPlunk]

Originally Posted by BADDASSC6

Sean, the displacement claims are marketing bullshit. each chamber is 1.3 liters there are three of them per lobe and two lobes in a 13b. Each one fires every revolution. If we follow the 1.3 liter rule then a Dodge viper has a 1 liter engine.
They have the worst emissions of any modern motor, the apex seal die (hence no more turbos), and Hondas have a better torque curves.

People think they are cool because they do not have reciprocating parts, but they fail in every quantitative category.

Don't forget that they are expensive to rebuild.

Sean, you like the Kia Soul????????????????????????? GAY

I think you're a closet Kia Soul lover too

As far as emissions and gas mileage are concerned - you are indeed correct. You can't compare everything to an LS7 though - it's not fair to everyone else

[enkeivette]

Originally Posted by BADDASSC6

No way. Again NO WAY! Each cylinder in my car is only ~.75 liters not 6 or 8 liters. Only half the cylinders fire per revolution. On a rotary EACH LOBE creates CHAMBER that measures 1.3L, there are THREE CHAMBERS PER LOBE (look at your simple little drawing), all of them conduct a complete intake, compression and exhaust cycle.

Dude, you just proved my point:

"If whats improtant is how much air/gas a motor can move per revolution" then I'm rocking a 3 liter and a RX-7 is rocking a 7.8 liter. Now I will run ANY NA rotoray.

I wasn't saying each cylinder was 6 or 8, I was saying each cylinder is 6/8ths (fraction) = .75

But I do see your point, I was confused on what it was. You're saying that since there are 3 compression strokes for each revolution of the output shaft, that you need to count each one which would be 1.3L/2 x 3 (compression) x 2 rotors which is 3.9L

I can see that line of thinking. But it's sort of not fair, because you're using the back of the rotor and counting it as displacement while you'd never count the area behind a piston as displacement obviously. So there is more effective intake charge displacement while there is less actual displacement.

Because realistically, you're counting the same air space inside the rotor chamber 3 times.

[enkeivette]

I'm going to leave this saying that you're partially right, I was partially wrong and you just can't measure displacement in a rotary the same way you do in a piston engine.