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Date: Thu, 17 May 2012 09:09:52 -0400
From: Ernest Christley <echristley@att.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: BSFC and EGT
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Gordon Alling wrote:
> If I read this plot correctly, the SFC is reported between 0.6 and 0.7 over
> most of the range.  What units are used?  Lb/Hp-Hr?  If so, this seems a bit
> high for a four-stroke spark ignition engine at cruise setting.  I would
> expect to see 0.45 - 0.55 Lb/Hp-Hr.
>

That was my thought, too, Gordon.  I also notice that the BSFC is almost static between 0 and -175 or so.  Seems to make
sense.  The efficiency gained by using less fuel in the mixture would be offset by the efficiency lost by the mixture
not being rich enough to burn completely.  That condition would hold for a bit until it gets so lean (and cold) that it
will hardly burn at all.  The bottom end where the BSFC curve shoots up dramatically is probably where the engine is
running rough from a increasing number of misfires, all the way to the point where it won't run anymore?

This again makes me wish I had added the GPIO board to my MegaSquirt, so that I could record EGT.