All this talk of additional power coupled
with an easier intake design has me thinking I should probably go this
direction with my Renesis. It’s still on the stand after rebuild.
I haven’t constructed the manifold
yet anyway.
I assume fuel flow will be higher than
normal?
Is slide throttle best option?
Need to search archives I guess.
Good info Lynn, Thanks
Bryan
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Lynn Hanover
Sent: Monday, June 21, 2010 12:15
PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: 13B
rotary engines
In a message dated 6/21/2010 11:03:01 A.M. Eastern Standard Time, rv-4mike@cox.net writes:
Thanks for the
feedback Lynn.
Unusual to see a "poor port design" actually aid performance.
It is not obvious until you start graphing the open and close events,
but the side port which uses the side of the rotor as a shutter to open and
close the port, offers Mazda great latitude in port timing. In the
periphery ported engine (both ports) it is impossible to arrive at zero
overlap, and have an engine that will produce any power at all. The apex seal
does not close off either port at all, it just valves gasses in one direction
or another.
In addition, the overlap of the periphery ported engine is far more
effective flow wise than overlap in the side ported engine. One apex seal is
above the intake port when the opposing apex seal is below the exhaust port.
Flow between the two is unobstructed.
So, at low RPM you get fresh mixture leaving through the exhaust port,
and combinations of burned and unburned fuel and exhaust gasses flowing partway
back into the intake runners.
This reduces the low RPM output to the point that the engine seems quit
docile, and is easy to drive around in the car, slowly, or possibly taxi in an
aircraft. This would make off idle tuning data useless as there will be
fuel burning right on top of the EGT probes, and unburned fuel reaching the F/A
sensor.
The engine will act along the lines of a piston engine with a long
duration cam. When the engine reaches its happy RPM where all of the mixture is
burning inside the engine, it will step up on the "CAM"
and you will see what a good idea this was. Use slow throttle inputs until you
find the "WOW" RPM, and be ready with all available rudder.
When we first ran a factory periphery port engine, we found that there
were places on the track that would not allow full throttle. This with 11"
wide slicks. Thank Heaven for rev limiters. The driver reported the rear end
getting real loose cresting hills and bumps.