Side/Peripheral port flawed design?

Post anything that doesn't belong in any other forum, including gaming and topics unrelated to motorsport. Site specific discussions should go in the site feedback forum.
mzivtins
9
Joined: Wed Feb 29, 2012 11:41 am

Side/Peripheral port flawed design?

Postby mzivtins » Mon Nov 30, 2015 5:21 pm

Bare with me guys, i am trying to understand pros, cons and limiting factors between different Engine types and ways to tackle Intake/Exhaust valves/ports.

I have a keen interest in Rotary engines, and i find myself in deep though around the efficiency of the NA engine.

Long story short:
Does variable valve timing and variable valve lift create, by way of gas flow, a variable tract in which the gasses can flow?
At different RPMs and engine loads i could imagine the need for different 3 dimensional intake and exhaust profiles?

In a rotary the valves are simply ports, much the same as any ported engine, the ports remain exclusively one size and shape. Is this fact alone; proof that the rotary in the way of the Wankel, a flawed design in a varying RPM engine?

It seems logical to me that ports can only be profiled to benefit a small range of engine operations, and yes do that very well (Simple half-bridge porting a side-ported rotary yields nearly a 20% peak power increase)

The 3 dimensional effect on gas flow is not always so apparent as everything is always only considered in 2 dimensions in its design (Like a fan blade)

What genius idea would you have, to grant a rotary a variable tract/port?

tuj
14
Joined: Fri Jun 15, 2007 2:50 pm

Re: Side/Peripheral port flawed design?

Postby tuj » Thu May 26, 2016 2:44 pm

Well one of the ideas Mazda used was secondary and aux ports that opened up at higher rpms on the intake side to better control mixing in the chamber. Another was profiling the port to the engagement of the rotor as it passed by, eg. the equivalent of cam-lift. On the RX-8 if you didn't run the motor past 7k rpm's on a regular basis, the aux ports would clog with carbon and not open.

J.A.W.
12
Joined: Mon Sep 01, 2014 4:10 am

Re: Side/Peripheral port flawed design?

Postby J.A.W. » Fri May 27, 2016 10:41 am

tuj wrote:Well one of the ideas Mazda used was secondary and aux ports that opened up at higher rpms on the intake side to better control mixing in the chamber. Another was profiling the port to the engagement of the rotor as it passed by, eg. the equivalent of cam-lift. On the RX-8 if you didn't run the motor past 7k rpm's on a regular basis, the aux ports would clog with carbon and not open.


Wow, maybe Toyo Gogyo ought to have bought rights to the Yamaha YPVS 2T system, that provided for a self-cleaning
valve arrangement for RPM related aux' port opening/torque-economy functions..
Dr Everett V. Scott sez.. " I happen to know a great deal about a lot of things."




Return to “Off topic chat”

Who is online

Users browsing this forum: CCBot [Bot] and 0 guests