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No, Mike, you correct, you do not NEED the injector
disable switches. However, there are several reasons why you might want to
consider installing them.
Should you ever have an injector malfunction -
say their wire to the EC2 grounds on your firewall- in that case, the
injector (or both assuming both of their wires grounded) will go to full
open and could possibly flood your engine - particularly if you are operating at
lower rpms. With a disable switch you could turn that pair off and fly on
the other.
Even if an single injector stops functioning properly, the
engine is affected - depending on what the injector malfunction is - the engine
will likely not operating smoothly - so simply turn off the effected injector
pair and fly home - without a sputtering or bucking engine.
You see your EGT start acting up - you could determine
which set of injectors (primary or secondary) is causing the problem and from
there which particular injector of the pair (rotor 1 or rotor 2 assuming
you have a separate EGT for each rotor) may be bad or acting up.
I had a malfunction one time where the cold start function
was forced on (nothing to do with the switches) - with the cold
start function engage and both pairs of injector operating
the engine had way too much fuel (even when the mixture control was turned
to minimum), but switching off one pair made it possible to get home with no
problem.
You can also use them to shut your engine off immediately
- even with fuel in the lines, if you turn off the disable switches, the
injectors will immediately stop injecting fuel.
But, you are right, they are a point of failure,however, I
would not consider them a single point - unless you have the bad luck to have
both of them go out at the same time, because so long as one is working, you can
fly on one pair of injectors with no problem.
Again, the choice is up to you, but they do have some
benefits.
Ed
----- Original Message -----
Sent: Thursday, May 31, 2007 11:35
AM
Subject: [FlyRotary] Re: It is ALIVE!!!
First Start in Houston
Is
there a reason you need an injector disable switch? Just looks like
another failure point and an increase in risk. Mike LaFleur
-----
Original Message ---- From: Mark Steitle < msteitle@gmail.com> To: Rotary
motors in aircraft < flyrotary@lancaironline.net> Sent:
Thursday, May 31, 2007 8:19:39 AM Subject: [FlyRotary] Re: It is ALIVE!!!
First Start in Houston
Dave,
Congradulations on first start!!! It is a real rush to hear your
baby breathe its first breath.
As for the "Disable" switches, Tracy and I had a discussion on this issue
just a few weeks back. He assured me that I wasn't the only one confused
by the logic of the disable switches. He now recommends that UP be ON
(normal operation), and DOWN be DISABLE. My little pea brain understands
that.
Glad you figured it out so quickly.
Mark S.
On 5/30/07, David
Staten <Dastaten@earthlink.net> wrote:
We
are prolly gonna go with UP for ON and DOWN for OFF. That seems to be
the
simplest for us southerners :)
Yea.. it was the injector power
switches.
Dave
Bob White wrote:
>Congratulations
Dave and Chris. Brings back memories of my first
>engine
start. Are the switches you had to turn over the injector
>disable switches? If that was my diagram, up is for
_disable_ and down
>is for run! As long as they work the
way you want that's the way to
>wire them. :)
>
>Bob
W.
>
>
>On Wed, 30 May 2007 22:10:06
-0500
>"Christopher Barber" <CBarber@TexasAttorney.net>
wrote:
>
>
>
>>Oh, and for those playing along,
we did install the check valve properly <g>. So far only a
minor oil leak from a plug in the engine Dave thinks he may have just
snugged in by hand and forgot to tell me to get back to and a small coolent
leak on a temporay hose connection. Really, really small in both
cases....almost non issues. FWIW.
>>
>>Thanks
again for y'all's support and well wishes.
>>
>>All the
best,
>>
>>Chris
>>Houston,
Texas
>>Ellington Field
(EFD)
>>
>> ----- Original Message
-----
>> From: Christopher
Barber
>> To: Rotary motors in
aircraft
>> Sent: Wednesday, May 30, 2007 9:54
PM
>> Subject: [FlyRotary] It is ALIVE!!! First Start in
Houston
>>
>>
>> It actually
started. We turned it off and it started
again. WAHOOOOO. But a mear wahoooo doesn't quite
express the amazing feeling and sense of accomplisment of first engine start
of the 2nd gen, turbo housing 13b.
>>
>> David
and I rebuilt it about 1.5 years ago. Dave did most the teardown,
cleaning, measureing tolerance etc and we both rebuilt it following along
Bruce T's video and the Haynes shop manual. Dave final install on
the CC engine mount and Tracy's PSRU. I ran the wires,
hoses...and the rest. A true joint effort.
>>
>> We tried last night to no
avail. Turns out when I wired the injector switches based on a
great diagram from the Flyrotary list, the illustration stated "top" and I
installed that end up with the swithes being up when on. However,
when I was checking my wires this pm I noticed that power was coming through
the switch when the switch was down.....doh! So, I turned them
over and rechecked the rest of my wires and grounds.
>>
>> In a damn optomistic gesture while in a
pessimistic mood, my hangar mate, Richard Sessions (who is restoring a
VariEZ) and my S/O, Jana and I pushed the tale of the Velocity out the
hangar door (of course it started sprinkling <g>) (Dave was still at
work). We took basic security procedures, ie showing Jana how to
use the fire estingusher. I turned on the switches (including the
now correclty mounted injector switches), turned on the primary fuel pump,
hit the starter button and DAMN, it fired.........SCARED THE HELL out of
us.......you should have seen my two Cairn Terriers (Winston and Madison)
head for the hills (well, Houston has no hills, but y'all get the
idea). We kinda looked at each other in a mixed shock and
amazement and checke that we didn't blow anything off. We
actually mixed fuel, air, compression and spark and got
combustion.....who'ed of thunk it?
>>
>> We
waited for the portable battery charger/starter to bring the battery back up
and tried again. Switches up, Pumps on, press the starter button......damn,
it sputtered and started (after some cranking). It
started to rev really fast, or seeminly so, so I brought the throttle to
closed, which didn't stop it, so I cut the fuel pump and it stopped. Go
figure.
>>
>> Well, we did this a few more
times, never running it too long since we do not yet have sensors on it yet.
Also, Dave got off work and came by to join the fun. Just the
fact it actually ran was great. Now that Tracy should be getting
back into town, we should be able to order the correct sensors to replace
the ones that were missplaced along the way.
>>
>> Not quite sure what to work on
now. Obviously we will want to smooth it out and get it to start
easily. It is currently running better on B than A. I
may have inavertanly changed someting on A while messing with it during
start sessions (may need to reset A...donno yet). I think I will
now try to start to clean up the wiring so as to make it easier to
manipulate the stuff in the cabin. Righ now the panel is laying
where the front seats should be. So this may be a good starting
point while waiting for sensors that will let me know I am not ruining my
new engine.
>>
>> Y'all's support and words of
wisdom, along with Tracy Crooks great products it what helped make this a
reality. Thanks for being there. NOW THE REAL WORK
(read that as fun) BEGINS.
>>
>> Dave will be
posting a much more technical account soon....heck, I bet we both rushed
home so we could annouce it to the
world.
>>
>> Thanks.
>>
>> All
the best,
>>
>> Chris
>> Velocity
N17010
>> w/ a Rotary 13b...that actually
runs.
>>
>>
>
>
>
>
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