Intake Design Exploration

[NoDOHC]

I should clarify a previous post. I re-read it and got confused myself.

Originally Posted by NoDOHC

I know that the rotary engine has a 298 degree intake port duration each revolution, making the airflow into the two rotors overlap (one is still filling when the other starts). This is also why the engine is so smooth, as the power strokes of the two rotors overlap. The actual maximum to minimum volume cycle of the engine occurs in 270 degrees of eccentric shaft rotation.

It is true that Rotor 1 (front) is taking in air during the same time that rotor 2 (rear) is taking in air (port active 288/360) = 80% of the time - therefore 60% of the time, both rotors are on an intake stroke. Unfortunately, I improperly computed the stock port open time for a 4-port (It is actually 288 degrees - 32 degrees ATDC and 50 degrees ABDC = 270-32+50 = 288). The 6-port is 268 degrees with ports closed (270-32+30) and 318 degrees with ports open (270-32+80).

My apologies on the misinformation.

The cool thing about the rotary engine is that although the port open time is overlap-equivalent to 2/3 the timing for a piston engine - 192 degrees for a four port (talk about a tame cam), the air has the same amount of time to enter the rotor as it would with 288 degrees of intake duration on a piston engine. Bear in mind too that well-ported ports on a rotary flow much better than an equivalent-sized valve (over 3 square inches of area between the ports would require one 2+" valve or 2 1.4+" valves). This is why the intake manifold is your biggest friend (or enemy).

Thanks for all your research in this vex!