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From: <daveleonard@cox.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Engine run
Date: Fri, 27 Aug 2004 10:17:22 -0400
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> 
> I'd really like to know what others are seeing for MAP 
> at idle from 800 RPM to ~2000 RPM.
> I can't seem to get below about 15inches Hg.
> Would any of you guys who have flown or have smooth 
> running engines at idle please respond with what your 
> normal MAP vs RPMs are for the low end around idle.
> I have a TWM DCO 48mm throttle body and a short Atkins 
> manifold.
> Thanks,
> Jim

In my plane it is actually not very reproducable.  It's a little different each time.  but typically, I will be down to about 12" or 13" at 1400 or 1500 RPM.  As I decrease RPM further the MAP starts to RISE (not enough RPM to support the vacuum).  This is the realm where the engine runs fairly rough.  Probably because each gulp of air/fuel is a different size than the last.

Dave Leonard