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Not to my knowledge, Jerry. Regardless of how
it gets into the combustion chamber, amount of gasoline burned = power
produced. I used 0.55 for all my calculations and that always seemed to get
me right on the money. I would say stick with the 41 lbs ones -
if you should be so fortunate to later find you need 50 lb/hr or higher,
hurry to the nearest auto store with a big wide grin {:>) and buy
the bigger ones and I'll buy the 460 cc/min ones from you. How's that
for a deal?
Ed A
Sent: Wednesday, March 23, 2005 11:46
AM
Subject: [FlyRotary] Re: fuel injector
size, and redrive losses
Thanks Ed, is there any reason not to trust the standard
formulas for determining injector size for the rotary? I ask only because
running those formulas the #42 seems to be just about right for my p port (220
hp) unless the BSFC goes above .60. Eighty per cent duty cycle is 41 lbs. With
a lower BSFC no problem at all, of course. I was surprised to learn that the
42 lb injectors were stock on older 13B NA. Does this point to a higher BSFC
than recips? Jerry
On Wednesday, March 23, 2005, at 10:58 AM,
Ed Anderson wrote:
Jerry, the older 13B NA
(post 1986) used 460 cc/min (Peak and Hold - Low
resistance) injectors approx 42 lbs/hr (this is what I fly with).
The first turbo units used 550 cc/min injectors (saturated types - higher
resistance), I have flown with these but found I did not like the idle as
well as the 460 cc/min units so
reverted.
Ed
A
----- Original Message
-----
From: Jerry
Hey
To: Rotary
motors in aircraft
Sent: Wednesday, March 23, 2005
10:45 AM
Subject: [FlyRotary] Re: fuel injector size, and redrive
losses
Mark, is your engine a N/A 13B? Do the 550s equate to a little
more than 50 lbs/hr? That is hugh. Did you find the 42 lb/hr injectors to be
too small? Lastly, can someone tell me the size of the stock Mazda
injectors? Thanks, Jerry
On Wednesday, March 23, 2005, at 09:25
AM, Mark R Steitle wrote:
Jerry,
I bought a set of eight 42#
Ford injectors but in the end, wasn’t able to use them and went with the
550’s.. I gave $320 for the set and would let them go for my cost.
I’ll split the set if someone else wants the other four. They
have about 5 hours on them. If you’re interested contact me off
line.
Mark S.
mark.steitle&Austin.utexas.edu (replace &
with @)
<image.tiff>
From:Rotary
motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf
OfJerry Hey
Sent: Wednesday, March 23, 2005 8:12
AM
To: Rotary motors in aircraft
Subject: [FlyRotary]
Re: fuel injector size, and redrive losses
Ken, after
spending the day calculating injector sizes, I ended up coming to the same
conclusion that you did. The Ford 42 lb are perfect for my application. P.L.
recommended 50 lb injectors but for 225 hp they are too much in my opinion.
Unfortunately Ford Racing is out of stock. Damn. Jerry
On
Tuesday, March 22, 2005, at 06:06 PM, kenpowell@comcast.net
wrote:
Jerry, the Ford injectors are not directly
compatible. Here are the
details:
ENGINE SIDE FUEL RAIL
SIDE
Ford
0.55"
0.55
Mazda
0.65 (with the FAT Mazda rubber
ring)
0.435
Note that the electrical connector is the same (center spline
top/inside and center lower outside). So, the Ford injector will hook
up electrically but the fuel connectors must be different.
Ken
Powell
Bryant,
Arkansas
501-847-4721
--------------
Original message --------------
> Ken, are the Ford
injectors interchangeable with the stock Mazda
> injectors as far
as size, plug and so on? If so, do you have a part
> number? BTW
sorry but there is no way you can run a p port at 7500
> rpm and
only get 225 hp. Can you accept 240?
Jerry
>
>
>
>
>
>
On Tuesday, March 22, 2005, at 03:48 PM, kenpowell@comcast.net
wrote:
>
>
> But this graph was for a
carburated engine so it really
> proves nothing. Besides, the
engine only needs to be as rich as we
> want to run - you can't
hurt the engine by running lean (I know, if
> you run it into the
trees on a 100 F. day that will HURT it!!!). I
> have not seen any
graphs showing power improvement beyond 0.6 on a NA
> engine and
with very little to be gained by going beyond .55. If
> anyone can
educate me differently please do so (no kidding, I'm trying
> to
learn). I'm planning on using 42 lb Ford injectors for my P-Port
>
motor, if this isn't enough I want to know (planning on 225 HP at
7500
> RPM).
>
> Ken
Powell
>
> Bryant, Arkansas
>
>
501-847-4721
>
>
>
>
>
-------------- Original message
--------------
>
>
> v\:*
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>
w\:* {behavior:url(#default#VML);} .shape
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}
>
> Arial0000,0000,8080Rus
>
ty,
>
>
> Arial0000,0000,8080Are
>
you sure youÌre allowing yourself enough margin on the top end
by
> using .55 bsfc. This chart (snitched from the other list)
indicates
> that .55 is about right up to around 7500, but at 8000
rpm bsfc will
> be up around .60. What does that do to your hp
numbers?
>
>
>
>
Arial0000,0000,8080
>
smaller>
>
>
>
Arial0000,0000,8080Mar
> k
>
S.
>
>
> Arial0000,0000,8080
>
smaller>
>
>
><
>
>
>
>
Arial0000,0000,8080
>
smaller>
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>
><
>
>
Times
New Roman
>
>
>
>
From:Rotary motors in
> aircraft
[mailto:flyrotary@lancaironline.net] On Behalf
> OfRussell
Duffy
>
> Sent: Tuesday, March 22, 2005 2:25
PM
>
> To: Rotary motors in
aircraft
>
> Subject: [FlyRotary] Re: fuel injector
size, and redrive
> losses
>
>
>
Times New Roman
>
>
> Times New RomanRC
Engineering's calcs show
> that you are good to 302 HP at 43 psi
fuel pressure, .50 BSFC, and
> 100% duty cycle. Of course you
can't run the injectors at 100%
> (except maybe briefly like a
drag race, not applicable to aircraft).
> So at 80% duty cycle the
38 lb injectors should be good for 242 HP.
> Enjoy your idle!!!
Your injectors are big enough unless you P-Port
> and turn at
least 8000 RPM.
>
>
>
>
ArialFFFF,0000,0000Hi
> Ken,
>
>
>
Times New Roman
>
>
>
ArialFFFF,0000,0000RC
> Engineering's calc shows the same as the
fuel calculator that I
> posted the other day. Four 38 lb/hr
injectors, at 80% duty cycle, .55
> BSFC, should be good for about
220 HP at the flywheel. I imagine that
> will be enough for the
current engine, but not by a wide margin. I
> plan to run this
engine as high as 8000 if I can, though I'll be
> amazed if I can
get beyond 7500. Don't need no stinkin' P-Port for
> these rpms
:-)
>
>
> Times New
Roman
>
>
> ArialFFFF,0000,0000On
>
the fuel spreadsheet that I posted (stolen) the other day, it gives
a
> HP figure for the flywheel, and rear wheels. The estimate
for
> the power loss due to a manual trans and diff is 15% on
this
> spreadsheet. Anyone know what this amounts to for our
redrive, and
> prop?
>
>
> Times New
Roman
>
>
>
ArialFFFF,0000,0000Cheers,
>
or>
>
>
>
ArialFFFF,0000,0000Rusty
> (hoping Ed out types
me)
>
>
> Times New
Roman
>
>
> ArialFFFF,0000,0000
>
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>
>
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