|
|
You are right, Bob. My experience with SAG (quite a bit actually) is that it is at its more frequent and worst at high power settings - like right after take off.
One day on way to Tennessee, I loaded up my RV-6A with fuel at a small airport around mid day and took off. Both rotors (usually its only one at a time) immediately went into SAG with me heavily loaded with fuel and gear. My heart was a thumping and the seat cushion was also taking a beating - until I realized I was still climbing at 500 fpm. While far below my normal 1200 fpm+, it was better than I got on a Cessna 150 on most days. So I orbited the airport and climbed to 5000 feet over it. Then I pulled back on the power, the condition cleared up and off to Memphis I went. I met Tracy Crook there and described my problem and he handed me a set of spark plugs - he always carries an extra set and so do I now.
So don't know whether SAG had anything to do with your problem, but folks should be aware because it can act a lot like an injector problem - I tore my hair out over it when I first encountered it for days, taking the intake off, swapping injectors, etc. Then when I was describing the problem/symptoms to Tracy Crook, he is the one who suggested it might be a spark plug problem. Changed the sparkplugs and problem went away.
I generally get from 20 - 30 hours with 100 LL but it has been as few as 12 and as many as 38 hours on a set.
Ed
----- Original Message ----- From: "Bob White" <rlwhite@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Friday, June 01, 2007 4:48 PM
Subject: [FlyRotary] Re: Injector disable swtich orientation was [FlyRotary] Re: It is ALIVE!!! First Start in Houston
Now that is interesting. The plugs have a little over 10 hours on them
but I'm running 100LL and may not have had the mixture set very well
for part of that time. I didn't know turning off a set of injectors
would help SAG. It could be that if I had disabled the secondaries
instead, that would have helped too. I will look for any evidence of a
ground problem in the EFI cable too but I think it was in pretty good
shape.
If it was SAG, I would have been in deep trouble if it had happened
just after liftoff. (Actually true no mater what the cause.) That's
another thing too, I wasn't running at full power at the time and my
understanding is that SAG is worse at WOT.
Bob W.
On Fri, 1 Jun 2007 16:17:42 -0400
"Ed Anderson" <eanderson@carolina.rr.com> wrote:
If it bogged down, Bob. That implies to me that it was getting too much
fuel. An injector could stick open because of a short to its grounding
wire. If it did then removing power from the injector by turning off the
injector switch would cause it to close again. The only other thing I can
think would be spark plug SAG which will cause the engine to lose rpm and
EGT on the affected rotor to drop. I have been able to temporarily get rid
of the SAG by turning off one pair or the other for a moment.
Doubling the flow with the cold start will work Ok provided only 1/2 of your
injectors are enabled.
Ed
----- Original Message ----- From: "Bob White" <rlwhite@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Friday, June 01, 2007 3:46 PM
Subject: [FlyRotary] Re: Injector disable swtich orientation was [FlyRotary]
Re: It is ALIVE!!! First Start in Houston
> Hi Ed,
>
> I guess I has assumed the injector couldn't be stuck open because I
> would have been getting way too much gas to the engine and disabling it
> wouldn't have helped because it would still be stuck open. Further
> flow thru the secondaries would be doubled because cold start was
> activated giving me extra gas. I could probably have answered that
> question if I had taken a look at the EGT's and mixture.
>
> The engine ran normally with the primaries disabled but wouldn't make
> power with them enabled. It didn't run rough, it just bogged down.
>
> Bob W.
>
> On Fri, 1 Jun 2007 15:10:33 -0400
> "Ed Anderson" <eanderson@carolina.rr.com> wrote:
>
>> Sorry, Mike, responded to the wrong question. Regarding Bob' problem:
>>
>> IF you have one or more of your primary injectors stick open (for
>> whatever reason) then the extremely excessive fuel flow could drown >> your
>> engine or at best make it operate abnormally.
>>
>> By switching off the primaries and leaving only the secondaries on - >> he
>> temporarily removed whatever in the primary circuit was causing the
>> problem - my guess is that it would be an injector sticking open. >> But
>> even if it was an injector sticking close and causing abnormal engine
>> running due to too little fuel - by switching off the offending pair
>> causes the EC2 to double the fuel flow of the remaining injector pair >> so
>> you end up with the fuel needed to stay in the air.
>>
>> It could have just as easily been the other way around, having to >> switch
>> off the secondary injectors and fly home on the primary injector >> circuit.
>>
>> That is one of the advantages of having the injector "disable/enable"
>> switch - you can use them to identify and remove the injector pair
>> causing the problem - if that is indeed the problem.
>>
>>
>> Ed
>>
>>
>> ----- Original Message ----- >> From: Michael LaFleur
>> To: Rotary motors in aircraft
>> Sent: Friday, June 01, 2007 2:53 PM
>> Subject: [FlyRotary] Re: Injector disable swtich orientation was
>> [FlyRotary] Re: It is ALIVE!!! First Start in Houston
>>
>>
>> Not Buly's problem, Bob's problem. The one at 8500 feet.
>>
>> Why would his engine run only with the secondary injectors?
>>
>> Mike LaFleur
>>
>>
>> ----- Original Message ----
>> From: Ed Anderson <eanderson@carolina.rr.com>
>> To: Rotary motors in aircraft <flyrotary@lancaironline.net>
>> Sent: Friday, June 1, 2007 9:19:58 AM
>> Subject: [FlyRotary] Injector disable swtich orientation was
>> [FlyRotary] Re: It is ALIVE!!! First Start in Houston
>>
>>
>> Mike, I believe the "problem" was in the orientation of the injector
>> disable switches in the panel.
>>
>> Normally, as you know, the convention for switches is "UP" is ON >> and
>> "DOWN" is OFF. However, in reading the schematic for wiring the
>> switches, they were (in this case) installed so that "UP" was OFF and
>> "DOWN" was ON (just backwards).
>>
>> So with the switches in the UP position (believing that turned the
>> power on to them) the engine would not start because in reality the
>> injectors were actually turned off. So a very simple solution (once >> the
>> problem was recognized) was to flip the switches DOWN (which in this
>> case turned the power on).
>>
>> The permanent solution is to rotate the switches to the >> conventional
>> orientation where UP is truly ON.
>>
>> Ed
>>
>>
>>
>>
>> From: Michael LaFleur
>> To: Rotary motors in aircraft
>> Sent: Friday, June 01, 2007 8:21 AM
>> Subject: [FlyRotary] Re: It is ALIVE!!! First Start in Houston
>>
>>
>> What was the root cause of your problem? I'm thinking there's
>> something seriously wrong when you have to disable a set of injectors >> to
>> get back running again.
>>
>> What was the long term fix to make sure this didn't happen again?
>>
>> That's the great thing about a forum such as this is that we can >> all
>> learn from each others incidents and make all our planes safer.
>>
>> Mike LaFleur
>>
>>
>> ----- Original Message ----
>> From: Bob White <rlwhite@comcast.net>
>> To: Rotary motors in aircraft <flyrotary@lancaironline.net>
>> Sent: Thursday, May 31, 2007 12:05:56 PM
>> Subject: [FlyRotary] Re: It is ALIVE!!! First Start in Houston
>>
>>
>> Hi Mike,
>>
>> On the rotary engine, it's extremely valuable. I was happily >> flying
>> along at 8500 ft. 10 miles from the airport when the engine >> suddenly
>> lost power (Ground level here is about 6000 ft.) I wasn't getting
>> enough power to maintain altitude. First I switched to the B
>> controller, no help. While looking at which field I wanted to land
>> in,
>> I started looking for more things to try. The next step I took >> was
>> to
>> disable the primary injectors. The engine took off again and I
>> continued the flight to land at the airport. The injector disable
>> switch saved me from an off airport landing.
>>
>> Bob W. (It wasn't a great landing!)
>>
>>
>>
>> On Thu, 31 May 2007 08:35:43 -0700 (PDT)
>> Michael LaFleur <mike.lafleur@sbcglobal.net> wrote:
>>
>> > 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.
>> > >>
>> > >>
>> > >
>> > >
>> > >
>> > >
>> >
>> >
>> > --
>> > Homepage:
>> > http://www.flyrotary.com/
>> > Archive and UnSub:
>> http://mail.lancaironline.net:81/lists/flyrotary/List.html
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>>
>>
>> -- >> N93BD - Rotary Powered BD-4 - http://www.bob-white.com
>> 3.8 Hours Total Time and holding
>> Cables for your rotary installation -
>> http://www.roblinphoto.com/shop/
>>
>> --
>> Homepage: http://www.flyrotary.com/
>> Archive and UnSub:
>> http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>
>>
>>
>>
>>
>
>
> -- > N93BD - Rotary Powered BD-4 - http://www.bob-white.com
> 3.8 Hours Total Time and holding
> Cables for your rotary installation - http://www.roblinphoto.com/shop/
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub:
> http://mail.lancaironline.net:81/lists/flyrotary/List.html
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
-- N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://www.roblinphoto.com/shop/
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
|
|