Mailing List flyrotary@lancaironline.net Message #18743
From: George Lendich <lendich@optusnet.com.au>
Subject: Re: [FlyRotary] Re: peripheral ports
Date: Tue, 15 Mar 2005 07:51:49 +1000
To: Rotary motors in aircraft <flyrotary@lancaironline.net>

 Group,
 I really would like to know where the idea that the PP rotary won't idle came from? 
This is total baloney. Lynn Hanover has commented several times that his PP 12A idles just fine. Some carburated engines with unusual manifolds sometimes have problems. This is true for both PP and side port engines. Many of the earlier rotary engines used P ports.
 If and engine is radically ported in either port type, (just like a radically cammed piston engine), it can be difficult to make idle. If you keep the port timing reasonable the engine ?WILL IDLE FINE, especially a EFI engine. The throttle plates being close to the housings makes things work better. The MB C111 used various rotary configurations. Most of the engines were peripheral ported. There was no problem with idle, but the sealing problems of that era prevented a production version. If your engine is set up carefully without radical timing idle won't  be a problem. The real problems encountered by many people are caused by large ports and extended port timings.
Bill Jepson
 
Hi, Bill....I got the idea that p-ported engines would not idle well from Mazda Racing, Mazdatrix, and 5 or 6 other shops that will p-port an engine. One example of other articles referring to the poor idle can be seen at www.monito.com/wankel/porting.html .  I am not making this up....just passing on what I have read from what I thought to be reputable dealers.  Paul Conner 

Paul, all the companies you list sell housings with BIG p - ports and massive overlap. They are designed to develop tremendous hp at high rpm for racing. Of course they don't idle smoothly. These engines have nothing to do with the smaller, conservatively timed p ports that we wish to use as aircraft engines. Jerry
Paul.
Massive side ports will not idle well either!
One must compare apples with apples.
One interesting point is Paul Lamar is developing 2" P-ports to prove his theory - so we will see what we will see.
George ( down under)
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