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From: "Jack Ford" <jackoford@theofficenet.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-938323@logan.com>
Subject: Re: [FlyRotary] Re: center rotor OFF
Date: Tue, 10 May 2005 06:43:56 -0700
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Thanks, Alex,

I'd still like to see some data on that. Where does the combustion 
efficiency cross the excess baggage curve?
Particularly when (I believe) friction losses are proportional to v ^2.

This is half in fun anyway.

Thanks again,

Jack Ford


----- Original Message ----- 
From: "Alex Madsen" <madsena@rose-hulman.edu>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Monday, May 09, 2005 8:32 PM
Subject: [FlyRotary] Re: center rotor OFF


> The stuff about having to still move all the engine components is true.
> However, you are missing the point that by shutting down one cylinder you
> can run the engine at a higher rpm with less fuel where the engine (per
> operating cylinder) is more efficient.
>
> Alex Madsen
>
>
>
>
> -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
> Behalf Of Jack Ford
> Sent: Monday, May 09, 2005 9:50 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: center rotor OFF
>
> That entire variable cylinder configuration routine seems to me to be a 
> lot
> of (old) advertising hype. The concept seems to be that the public thinks
> fewer cylinders burn less fuel, so you can have your eight cylinder cake 
> and
>
> eat four cylinder fuel. Purest balderdash.
>
> The engine is still pulling eight cylinders worth of rings back and forth 
> in
>
> the bores even if it's not compressing any air. The cam is still trying to
> lift sixteen (plus) valves and compress sixteen (plus) springs, ETC. You
> can't reduce a lot of the pumping losses if the whole mechanism is still
> rotating/reciprocating/wearing.
>
> Power is proportional to the amount of air/fuel mixture going through the
> pump (assuming the same combustion efficiency). The reduced air/fuel 
> mixture
>
> (of the variable cylinder configuration at cruise) presumably produces
> increased economy. BUT, it requires exactly the same amount of power to 
> push
>
> the vehicle down the road at cruise using 4,6,8,10 or 24+ cylinders. The
> conventional method of accomplishing this enterprise is CLOSING THE 
> THROTTLE
>
> so less air/fuel mixture is pumped through. Has the exact same effect with
> much less complicated design.
>
> So if you want more efficiency, just run at lower power settings. You will
> accomplish the desired result.
>
> Retracting soapbox,
>
> Jack Ford
>
>
> ----- Original Message ----- 
> From: "Ernest Christley" <echristley@nc.rr.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Monday, May 09, 2005 3:16 PM
> Subject: [FlyRotary] Re: center rotor OFF
>
>
>> Russell Duffy wrote:
>>
>>>  OK, make me look it up :-)  Apparently, they stop the valves from
>>> opening, rather than leaving them open.  I couldn't find anything that
>>> gave details of exactly what point in the sequence they stop the valves,
>>> so the cylinder could either be full of air (silly and wasteful of
>>> power), empty of air (would cause vacuum that would be as bad as the
>>> compression force), or perhaps somewhere in between.
>>
>>
>> Other than friction losses, you'll get back everything you put into
>> compressing the gas in the cylinder, Rusty.  The process will be totally
>> elastic.
>>
>> -- 
>> This is by far the hardest lesson about freedom. It goes against
>> instinct, and morality, to just sit back and watch people make
>> mistakes. We want to help them, which means control them and their
>> decisions, but in doing so we actually hurt them (and ourselves)."
>>
>>
>>>>  Homepage:  http://www.flyrotary.com/
>>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>>
>>
>
>
>
>>>  Homepage:  http://www.flyrotary.com/
>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>
>
>>>  Homepage:  http://www.flyrotary.com/
>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>
>