----- 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
>
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>
> --
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