----- Original Message -----
Sent: Sunday, October 16, 2005 7:38
PM
Subject: [FlyRotary] Displacement -
Again?
Been there, done that {:>). If you are
going to compare the power production of 13B rotary
engine with a normal reciprocating engine, then the accepted standard
for a power cycle (for a four stroke) is 720Deg crankshaft degrees
of rotation. 720 degrees of a reciprocating engine has all
cylinders firing be it a 4,6,8 or 12 cylinder engine.
Clearly the 80 CID or 1.3 Liters comes
from simplistic sum of the two 40 CID chambers per rotor. The
2.6 liters takes a bit more explaining.
Where I believe the controversy comes
in is that 720 degrees of a rotary leaves two faces of
the 13B yet unfired. For all six faces to fire it
takes 1080 degrees of crankshaft rotation. Each rotor face rotates
120 rotor degrees for a complete cycle- since the e shaft is geared 3:1
then 120 deg rotor rotation = 3*120 = 360Deg of E shaft
rotation. Or another way to look at it is 360 deg of rotor rotation
( a complete rotor revolution) = 3*360 = 1080 deg of e shaft
rotation.
Now you can argue that the rotary has not finished
its combustion cycle (all chambers firing) until all six faces have fire
(1080 deg) - however, the accepted standard for a complete cycle of
a reciprocating 4 stroke is 720 degs.
So IF you are interested in comparing oranges and
oranges, then its generally accepted you compare only 720 deg
of the rotary's rotation to equal the 720 deg of a normal 4 stroke
reciprocating engine.
IF you do accept that - then
that means 4 rotor faces have gone through their cycle in 720 deg
of e shaft rotation. So at approx 40 CID per face we have 4 x 40 =
160 CID for the 720 deg cycle. And that turns out to be 2.62 liters of
displacement.
Its really no different than adding up the
total displacement of all the cylinders in a reciprocating engine
which do happen to complete a power stroke in that standard 720
deg. I think the fact that two faces or (80 CID of displacement)
have not yet fire with the rotary is what bothers folks in this
comparison.
But if you are going to compare the power of the
two different designs of engine you have to pick one or the other as the
standard of comparison. And keep the parameters the same for both
engines. For example:
If you believe the cycle of the rotary is
not complete until all six faces have fired then you have 6 x 40 = 240
CID in the 1080 degree rotary cycle.
We could insist that the reciprocating engine be
compared to the 1080 deg rotation of the rotary, but then you would have
to increase the effective displacement of the reciprocating engine to
include an additional 1/2 of its displacement since it will have gone
through another 360 deg of rotation to match (720 + 360 = 1080) the
rotary cycle of 1080deg. That way you again have oranges and
oranges.
But, in that case both we and the recip
folks could boast about even more HP than we do now {:>)
Since I am mainly interested in comparing a rotary
with the reciprocating engines production of power, I adhere to the 720
deg standard for the comparison.
Not taking any sides , but someone asked
where the 2.6 liter figure came from and I hope I have answered
that.
Ed A
----- Original Message -----
Sent: Sunday, October 16, 2005 9:21
PM
Subject: [FlyRotary] Re: flyrotary_Web_Archive Re:
Banishment
> Hi
Dave,
>
> OK, one revolution of the e-shaft is 1/3
revolution of the rotors. So
> each rotor has had one intake
event. Each face has a calculated
> displacement of about
650 cc. Two X 650 cc = 1.3L. If you can explain
> why
it's 2.6L, maybe I can send Paul an apology. Or are you
just
> trying to get my goat? :)
>
> I'm not trying
to create a big discussion on the displacement of the
> rotary, I
just want to understand where that 2.6L per revolution number
> is
comming from. I haven't been able to see it. I think Paul
gets it
> from comparing to a piston engine, and I agree that the
13B compares
> closest to a 2.6L 4 cycle 4 cylinder
engine.
>
> Bob W.
>
>
> On Sun, 16 Oct
2005 16:27:59 -0700
> David Leonard <wdleonard@gmail.com>
wrote:
>
>> Monty, Glad to have you and you know you
will always be welcome here.
>> However, you are wrong and 'he'
is right about the displacement of the 13B.
>> It is 2.6L or
159.6 cubic inches to be more exact.
>> That is the
volume of intake on one revolution of the e-shaft.
>> But
I think you knew that, you were just trying to get his goat.
;-)
>>
>> --
>> Dave Leonard
>>
Turbo Rotary RV-6 N4VY
>> http://members.aol.com/_ht_a/rotaryroster/index.html
>> http://members.aol.com/_ht_a/vp4skydoc/index.html
>>
>> On 10/16/05, Monty Roberts
<montyr2157@alltel.net>
wrote:
>> >
>> > The doctrine of immaculate
ingestion. Whereby molecules of air and fuel
>> > magically
migrate into a very small, very perfect engine,unsullied by
the
>> > mere laws of physics, thereby creating the
salvation of the world through
>> > massive power
levels.
>> > In the protestant tradition of placing
the individual at the front of the
>> > line rather than at
the bottom of the church hierarchy, I will henceforth
>> >
place all replies at the TOP of each post.
>> >
Monty
>> > Which doctrine was that
Monty?
>> >
>> > Bob W.
>>
>
>> >
>>
>
>
> --
>
http://www.bob-white.com
>
N93BD - Rotary Powered BD-4 (real soon)
> Prewired EC2 Cables -
http://www.roblinphoto.com/shop/
>
> --
> Homepage: http://www.flyrotary.com/
>
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