Hey recently I’ve been looking into the design/engineering of the rotary engine and was wondering something that is probably pretty stupid but i will ask nonetheless. Why is the intake port inline with the exhaust port? This seems to create an overlap that gives the rotary its signature brap but why was it designed this way from a technical standpoint? Would it not be more fuel/power efficient to move the intake up/closer to the spark plugs so there is no exhaust-intake overlap?

 

See pic below.
After 270 BDC the rotor enters the compression stage so the intake needs to close around there. That needs to be balanced with making the intake port big enough.
Moving the exhaust port to the side in the RX-8 removed a lot of overlap but the exhaust doesn't flow as well.

 

You Tube

 

You should bridge port that hunk of plywood! :P

 

you're asking the right questions! we've seen some patent drawings over the years and there was one where the intake and exhaust are actually flipped, so the intake which needs to be kind of long is on the bottom and is an L shape next to the engine, and then this puts the exhaust on top

and then if you look at pics of the new 8C the intake is raised up and angled differently than we are used to seeing the thing on top is a high pressure fuel injector, so its direct injected, which apparently makes a huge difference

 

That and add some brap sound effects
to the model.

In all seriousness, I learned more making that model than I did rebuilding the actual motor.

 

so why was the intake originally placed lower down? Is it because it needs more time to atomize the fuel? In any case I suppose I’m asking if the intake could be placed just before compression

 

i'm not sure why it was placed where it was, probably looked nice or something. they moved it up starting with the Cosmo in the late 80's, but only to make room for the turbos

one of the big differences between the Rotary and a piston engine is that the strokes take place in different physical locations, so essentially the intake IS before the compression.
if you want the piston engine analogy, its like the valve isn't moving, but we are changing the port angle in the head

 

Love how confusing these little engines are hah! So if a rotary was to be redesigned, the intake port could be placed nearer to the spark plugs without any negative effects? Not that I’m planning on doing this, I’m just a curious (for better or for worse) highschooler.

 

maybe a little, it still needs to have the intake stroke!

the Rx8 engine went the other way, and it moved the exhaust port instead of the intake, essentially