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Advice on fuel system upgrades

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msm_9949(at)yahoo.com
Guest

Posted: Tue Dec 12, 2006 8:33 am Post subject: Advice on fuel system upgrades

Listers:

   

  I've just ordered a HacMan unit from Greensky Adventures and a Facet fuel pump from ACS (as back-up to Mikuni pump). Does anyone have advice on installation, operation of these units in context of Rotax 582-90 fuel system?

   

  A plumbing diagram for the Facet as a back-up would be really useful. Thanks in advance.

   

Marco Menezes

Model 2 582 N99KX

   Have a burning question? Go to Yahoo! Answers and get answers from real people who know. [quote][b]

Guy Buchanan

Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA

Posted: Tue Dec 12, 2006 10:06 am Post subject: Advice on fuel system upgrades

At 08:32 AM 12/12/2006, you wrote:

 	  Quote: 	
		  I've just ordered a HacMan unit from Greensky Adventures and a Facet fuel 

pump from ACS (as back-up to Mikuni pump). Does anyone have advice on 

installation, operation of these units in context of Rotax 582-90 fuel system?


	


I can't help you with the Facet pump, but I use the HACman and like it. I 

installed it per the instructions with few modifications and it works well. 

I exchanged their awful black tube wrapping for a plastic braided sock that 

looked a lot nicer. I also used an EPM.AV firewall fitting with a long 

piece of fire-sleeve on the firewall side to help preclude an engine fire 

entering the cabin after melting the vent tubing.



The only thing I can add that's not in the instructions is that when I'm 

flying I typically go full rich before any significant descent. I then 

descend at the angle I want and set the RPM's for 5800. I vary the angle of 

descent and RPM to get an EGT of 1200. If I get too steep, the EGT gets too 

high, even at 5800 RPM, (over-driving the engine,) so I pull it up, (slow 

down,) until the EGT's get back below 1200. (My EIS gives me a warning at 

1200 so the EGT's never get over about 1210F.) If I want to descend steeper 

I drop the RPM way down. (You have to watch the cold seizure then.)



 	  Quote: 	
		  


	


Guy Buchanan

K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.

_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too.

dosmythe(at)cox.net
Guest

Posted: Tue Dec 12, 2006 4:34 pm Post subject: Advice on fuel system upgrades

We had a discussion long time ago about the Facet  Backup on a 582.   About the only thing that can go wrong with the  standard Rotax pulse pump is 1. The pulse line ruptures causing the pump to  become inoperative.  2. The internal diagram of the pump ruptures causing  the pump to stop pumping.  In the case of #2, if you turn on the backup  Facet, the fuel will be pumped into the Rotax pump and then through the ruptured  diaphragm and into the crankcase.  In this case, a backup will do you no  good what-so-ever.  In the case of #1, if you turn on the backup, the fuel  will also be pumped out the ruptured pulse line and all over the engine.   Still not good.  Are there any new opinions on this possible  situation?

  

 Don Smythe

 [quote]   ---

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Tue Dec 12, 2006 6:11 pm Post subject: Advice on fuel system upgrades

One way valves ( out) on both  pumps and then plumb them in parallel. Takes care of all the problems you  stated.

  

  

 

Noel [quote]   

   --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

eskflyer(at)lvcisp.com
Guest

Posted: Tue Dec 12, 2006 6:22 pm Post subject: Advice on fuel system upgrades

Don 

 I totally agree with you on the fuel pump , and the  problems it can cause. I rebuild my mikuni pump every 2 years and have never had  a problem . it only cost $ 11 . to rebuild . Also replace the pulse line . Would  be easy to this even every year at condition inspection time . takes little time  and would really be worth the trouble . 

  

 Just my humble opinion 

 John Perry

  

  

  

   [quote][b]

dosmythe(at)cox.net
Guest

Posted: Wed Dec 13, 2006 4:58 am Post subject: Advice on fuel system upgrades

See drawing if this is what you are saying about  check valves on each pump.  This might help in the case of a ruptured pulse  line but would not do you any good with a ruptured diaphragm in the Mik  pump.   Follow the dark fuel line from the header to the  crankcase. Raw fuel will pass straight to the crankcase with a  ruptured Mik.  You would have to isolate the input to  the Mik but would probably be too late after discovery.  

  

 Don Smythe

  

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Guy Buchanan

Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA

Posted: Wed Dec 13, 2006 8:11 am Post subject: Advice on fuel system upgrades

At 04:33 PM 12/12/2006, you wrote:

 	  Quote: 	
		  Still not good.  Are there any new opinions on this possible situation?


	


I had a friend at the airport once claim that he had repeatedly suffered 

vapor lock in his fuel system in a 582 K-IV. He installed a Facet in series 

to cure it. His was the only occurrence of 582 vapor lock I could find.



I'm torn on the question of single-failure-tolerance. The only thing in a 

typical 582 installation that's single failure tolerant is the ignition 

system, and even that relies on a "single" stator for excitation. You could 

call the carbs and cylinders redundant, but you're not going to get very 

far on one cylinder. Everything else: gearbox, crank, bearings, rotary 

valve, cooling, oil injection, exhaust, charging, and finally fuel pump, is 

catastrophic. Realistically, if you demand single-failure-tolerance you 

have to fly behind a well designed twin. Otherwise you are relying on 

component and system reliability. We foolish pilots typically only demand 

redundancy for components that have a history of failing. The Mikuni pump 

appears to have a failure rate at least as good as the rest of the 582, 

which I grant you isn't saying much.



I guess the ideal replacement might be to get rid of the Mikuni and go to 

dual Facet's in series. Unfortunately that adds so much system complexity 

over the Mikuni that I hesitate to declare it significantly better. (Four 

connections, two check valves, two pumps, two electrical supplies, two 

switches, electrical requirement, two fuses, probably a fuel pressure gauge 

with all the attendant plumbing, manual operation including the possibility 

of flooding or forgetting to turn one on. You get the idea.) I decided that 

I would meticulously over-maintain the Mikuni and rely on its simplicity 

and autonomy for reliability.

Guy Buchanan

K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.

_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too.

msm_9949(at)yahoo.com
Guest

Posted: Wed Dec 13, 2006 11:25 am Post subject: Advice on fuel system upgrades

My bad Don. I checked the archives after posting my question. That discussion ended pretty much as it began, i.e., with different opinions on parallel backup vs series backup vs no backup at all. For me, the most relevant conclusion was that the Mikuni pump is probably the most reliable item forward of the firewall so why back it up? Just check it frequently and rebuild it annually.  So I'm sending the Facet back, trading it for a Mikuni rebuild kit.

   

  do not archive



Don Smythe <dosmythe(at)cox.net> wrote:

  [quote]        We had a discussion long time ago about the Facet Backup on a 582.   About the only thing that can go wrong with the standard Rotax pulse pump is 1. The pulse line  ruptures causing the pump to become inoperative.  2. The internal diagram of the pump ruptures causing the pump to stop pumping.  In the case of #2, if you turn on the backup Facet, the fuel will be pumped into the Rotax pump and then through the ruptured diaphragm and into the crankcase.  In this case, a backup will do you no good what-so-ever.  In the case of #1, if you turn on the backup, the fuel will also be pumped out the ruptured pulse line and all over the engine.  Still not good.  Are there any new opinions on this possible situation?

   

  Don Smythe

  [quote]  ---

dosmythe(at)cox.net
Guest

Posted: Wed Dec 13, 2006 12:19 pm Post subject: Advice on fuel system upgrades

Guy,

See below

---

dosmythe(at)cox.net
Guest

Posted: Wed Dec 13, 2006 12:24 pm Post subject: Advice on fuel system upgrades

Sounds like a fair conclusion to me.  The only  thing I would question is rebuilding the pump.  For some reason and I  don't know why, several Rotax articles I've read have suggested replacing  with a new pump over rebuilding???  They are after all, fairly  inexpensive.

  

 Don Smythe

 [quote]   ---

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Thu Dec 14, 2006 5:46 am Post subject: Advice on fuel system upgrades

Once it's drawn up it is very  easy to see the diaphragm leak you talk about.  My experience is mostly  with the diaphragm pumps on snowmobiles and on the older Tillitson carbs.   I have seen some diaphragm perforations.  What I have seen is basically the  engine shuts down so there is very little fuel overflow into the crank  case.  I suspect that with a second fuel pump the amount of fuel leaking  into the crank case will increase with the engine still  running.

  

 Two electric fuel pumps is no  better.... A problem with the electrical buss could immediately shut down the  engine.

  

 

Noel [quote]   

   --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

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