Backup fuel pump for IO-240 engine

[PapuaPilot]

I am wondering if anyone has installed a backup/larger fuel pump for a Continental IO-240 engine installation. The Facet fuel pump that came with my KF 5 Outback is only for priming the engine. It doesn't provide enough pressure/flow to run the engine in the event of an engine driven pump failure.

On certified planes with fuel injected engines there is usually an aux pump capable of keeping the engine running in the (unlikely) event that the engine driven fuel pump fails. Without one you become a glider . . . with an engine that could run otherwise.

Specs for the IO-240 show that it requires 35-53 psi of unmetered fuel pressure and about 12 gph at full power. I would think 20-25 psi and 8-9 gph would be enough to keep the engine running and get you home safely. I cannot find any 12 volt Facet or auto pumps with those kind of specs. I am getting ready to install the fuel system and think this would be the best time to make a change.

Is this something I should be concerned about or should I just stick with the Facet pump?

If someone has installed a larger pump what fuel pump did you use (brand, model number, specs)? Do you have pictures of your installation?

[airlina]

Good Morning Phil, There are but a few of us with IO-240's in our Kitfoxes but I know some are contributors to the forum. I have an IO-240 powered Series 5 Outback that I have been flying for 10 years and love the engine. Although heavy, it has been bulletproof and reliable with lots of power with good fuel economy. Now for your question on fuel pumps. Take the supplied facet pump and use it as a paper weight, it is not even stout enough for priming the engine. I used an automotive Holley "blue" pump as a substitute. It has enough pressure for good priming power and is preset at 14 psi . Will it keep the engine running if the engine driven pump quits? To be honest I don't know, I suspect at a reduce power setting but no way to check this. Price about $120 . If you want to be sure your pump will be a viable, keep the engine running backup pump, you will have to step up to something like a $600 weldon (see aircraft spruce) aircraft pump. I know of another IO-240 guy on the forum who has gone this route and I expect he will chime in ( Yo Jeff). As far as plumbing details- I came out of the header tank (just replaced my old poly tank with an aluminum one due to persistent fuel smell in cockpit ) to a "T" under copilot seat, then one branch of the fuel line goes behind copilot seat to Holley pump, and the other branch goes toward the center of the airplane thru an andair check valve then "T's" back into main fuel line to the fuel shutoff valve. This was done to keep fuel flow to engine in case the holley pump should ever seize and block fuel flow. I will see if I can find photos somewhere to make this clearer than mud. Bruce N199CL

[airlina]

Phil, we hit the jackpot as I found a photo cd of my fuel system that I made for another IO-240 guy a while ago. There are too many to put on Teamkitfox but I could try to email them or make you a copy and mail it to you. Send me a private message letting me know what you want to do. Bruce

[airlina]

OK Phil, here are a few photos of my fuel system. Photo 1 is looking down at header tank from the front-note the one way check valve (wrapped in fabric tape) and the fuel line heading behind the header to the fuel pump. Photo 2 is looking down on the header from the copilots door and you can now see the Holley pump. Photo 3 is at the back of the header . Photo 4 shows how the pump is mounted to an aluminum bar adeled to the fuse tubing. Hope these help, Bruce

[n85ae]

I use a Weldon pump in mine, I lost my engine driven pump on test flight #4
and I can assure you the Facet pump does nothing ... N85AE was a glider
luckily I was within glide range of the airport.

It was NOT inexpensive ...

http://www.aircraftspruce.com/catalog/eppages/weldonfuelpumps.php?clickkey=14901

regards,
Jeff Hays
N85AE, Series 5, IO-240B

[n85ae]

Mine is the Weldon 8163 I'm pretty sure it could run the engine in-flight but
after reading about how the fuel injection system works, the counter intuitive
way to keep the engine running IF you lost the pump would be - Turn on
pump, guess how much throttle you want (3/4), tweak mixture lever to
get engine to run at that position. If you wanted half throttle you would
would have to set 1/2 throttle, and pull/push mixture lever to where the
engine ran correctly. If you read the fuel injection manual for the IO-240B
it should clear up why the fixed pressure pump would require this tweaking
to keep running.

I believe the Holley Blue (which Bruce has) "might" be good for 1/2 throttle
likely at most, but surely not full throttle.

The Facet is a paperweight, and can "barely" start the engine. It trickles
fuel in at such a slow rate that the fuel injection system barely pops open
and feeds fuel. Whoever spec'd that pump for the IO-240B was in my
opinion - An imbecile (which is the polite version of my feelings). This is
based on my four miles, and a prayer, Series 5 glider experience.

Regards,
Jeff Hays

[SkyPirate]

Whats the minumum pressure requirement for the fuel injection?

[n85ae]

Completely variable, it's a combination of engine driven pump output which
is regulated by mixture lever position and rpm, which then is adjusted further
by throttle position. The injection system takes about 10 psi to pop open to prime the engine and around 37 psi at full power. So if you have a fixed output
pump as a backup it would require fiddling to get it to run at any given throttle
position in flight.

In other words it's not going to be a simple flip the switch and it's running like
nothing happened should the engine driven pump fail.

Regards,
Jeff Hays

[SkyPirate]

I had a variable pressure pump on my race car, it went from 13 to 45 lb pressure, i will try to find a link

[SkyPirate]

http://www.fuelab.com/

http://www.aeromotiveinc.com/

A couple examples mine was a holley set up with a mechanicl control with inline pressure guage

[n85ae]

I think any 30'ish psi pump would be good, those look like some decent pumps.
I did have the Holley Blue on mine for a while that Bruce has, but finally paid
for the Weldon. With the Weldon it is one of the easiest starting airplane engines
I have ever used. Unless it's really cold out then it's jumper cable time ...
The Odyssey back in the tail just doesn't have enough umph for really cold weather.

That Aeromotive 340 looks like a good pump to use. If I didn't have the Weldon
I might look at that. The Holley makes it start easy, but I think you'd get about
only 1/2 throttle max if you lost the engine driven pump in flight, with it as
a backup (it's about 14 psi).

Regards,
Jeff

[PapuaPilot]

Thanks everyone for your input and pictures. You all have been very helpful.

I'm a little concerned that the Holley Blue pump would be on the low side for an emergency pump because it only makes 14 psi maximum. Jeff's comment about it taking 10 psi to bypass the engine driven pump may mean that there is only 4 psi remaining the goes to the engine; this would barely get the engine above idle.

I am going to see if I can find a used 12 volt Dukes pump where I work. If not I will look into other options such as a new Weldon, CJ or Dukes pump.

I am planning on getting an aluminum tank and not even bothering with the poly tank that came with the plane.

[n85ae]

Let me clarify what I meant about the pressure:

The fuel injection system has a distribution block that has spring loaded ports. It
requires a certain amount of pressure (approx 10 psi) to get them to pop open
and allow fuel into the intake ports. With the Facet they will not really open
but basically leak fuel into the runners. This is why for example on the Diamond
Katana version of the motor, they use a modified drain on the intake runners
with a standoff to allow fuel to puddle to help with starting. Rather than simply
trickle out the drain.

On the IO-240B you want to have a LOT of pressure when you prime the
engine so it can "squirt" into the runner and splash fuel around. The excess
runs out the drains. However the splashed fuel vaporizes, and makes the
engine MUCH easier to start. Fly a Diamond with the drain solution they use
and you will fnd it is much more difficult to start than mine is.

Now in order to "run" the engine in flight, IF the engine driven pump has
failed you need a continuous amount of high pressure (30+ psi) to provide
enough fuel to run the engine at higher power settings. The pressure to
run the engine at "idle" for example requires 9.4 - 9.8 psi. With the pressure
required at 2800 rpm being somewhere around 30+ psi.

In an emergency with a fixed output pump, the engine would NOT be
regulating the pressure for you. So you would have to set the throttle
to some arbitrary position, and THEN adjust the mixture lever in and out
to adjust the pressure to where the engine would run approximately
correctly. This is assuming that the engine driven pump was not so fubar'd
that it could run at all anyway since your boost pump has to drive fuel
through the engine driven pump (the one which just failed).

Fly a Kitfox with an IO-240B and lose the engine driven pump one time in
flight, and I guarantee you will know a lot about it, just like I do "now" after
having had it happen to me.

Here's the truth about pumps on the IO-240B, I have used all three of
the below listed pumps.

1 - The Facet pump is inadequate.

2 - The Holley Blue makes enough pressure to start the engine, but could
probably NOT run the engine in flight.

3 - A 30+ psi pump makes starting a breeze, and "might" run the engine in
an emergency IF the mechanicals of the engine driven pump were not wrecked from the failure.

My pump failed, because the drive shaft seal failed, allowing the pump to suck
air and cavitate. This was part of a Critical Service Bulletin CSB-01-1 and
Teledyne replaced my pump for free after it failed EVEN though the engine
was not under warranty.

Regards,
Jeff Hays

[SkyPirate]

the problem today is finding a non EFI controlled pump,..this one doesn't list EFI control,..but a phone call would be best to confirm




http://www.summitracing.com/parts/acc-74701/overview/

[SkyPirate]

the above pump doesn't have a return line requirement..this is a plus,..a mechanical controller can be installed with a pressure gauge on the positive pressure side of the pump ( the fuel out side) I don't think it says that it is a free flow pump meaning it will or will not allow fuel to flow thru it without power,..some do some don't confirmation on that should also be asked if you order one

if a redundant fuel pump is applied to your system,..a check valve on the electric pump line between the primary fuel line and pressure gauge of redundant line so the main pump doesn't put back pressure on the electric pump,..and also on the main line between the primary pump and the connection point of the redundant pump so the electric pump doesn't put back pressure on primary pump

this set up might also require separate fuel shut off valves,..not knowing the type of mechanical pump your system uses

ok after re reading the bottom of your post if it will suck air,..it will also leak fuel if a secondary pump is installed with out a check valve

[n85ae]

You can always put a check valve in parallel to the pump if pump off flow-thru
is an issue. That's what I did with the Holley Blue pump when I was using it.

[SkyPirate]

actually ,..thinking about it,.. the pressure control valve I used had an off position,..it was a requirement in case of fire,.. one of the nascar rules for sanctioned tracks

[PapuaPilot]

Jeff, I think you are right about the Holley Blue being marginal and a 30+psi pump working. Good pressure will definitely give you better priming for starting.

The engine data sheet from Continental that came with my IO-240 shows it needs 35-53 psi of unmetered pressure for full power. During the full power run they had an actual 53.0 psi unmetered pressure that yielded 16.3 metered pressure. Unmetered pressure is what is coming out of the engine driven fuel pump, therefore I have to believe that you must have the same pressure from any backup pump (if you want full power).

I have a lot of experience working with Cessna TU-206s that have the Cont. TSIO-520. They have a 3 speed boost pump (Emergency, High and Low) that MUST be setup properly so the engine can run in case the engine driven pump fails. It uses the lower speeds with a throttle microswitch so the engine can run OK from cruise power to idle. The emergency position is incase you need full power, but you have to hold the red switch on as it is spring loaded to off. If the fuel flows are misrigged for the other two positions it can cause the engine to die because it is too rich or lean.

I looked online and think I found a Holley pump that should work great with the IO-240. The Holley model 12-920 inline pump shows specs of 67 gph @ 45 psi. It weighs 2.6 lbs. They say you must use a 40-100 micron filter before the pump (for warranty). This seems like a good idea to have the filter. I would put one at the outlet of the header tank and then tee it to a bypass valve and the Holley pump. I don't think it would need a regulator. Amazon has this pump for $176 and the filter for $64 which is a lot less then a Dukes or Weldon pump.

I like the Cessna 206 system but it is complex. There is another option. If you have enough fuel pressure for full power then you can keep flying if your engine pump fails. You would need to turn on the aux pump and open to full throttle; the engine will run. After that you can reduce power slowly (till it is getting rich/rough) and lean the mixture the engine runs smoothly again. If you do the power/mixture reduction in a few steps you can make the engine run all the way down till landing. At MAF,where I work, we used to have a standby emergency fuel pump system in our TU-206s that did exactly that. It used a second Dukes pump.

If I can't find a used (free) 12 volt pump at work I will most likely get the above mentioned Holley setup.

[n85ae]

Yep, that's exactly what I think. Continental used to have a chart that showed the unmetered pressure up to 2800 rpm, but I can't find it now. I have a couple
that show the metered pressure. The priming pressure issue, was one that a
Continental tech rep explained to me. I think if you get 30 psi or more, then
you should be able to tweak everything to make it run at least long enough
to get close to an airport.

I also found a note that the engine driven pump does have a built-in bypass for
exactly this reason.

Regards,
Jeff Hays

[N981MS]

After reading Jeff's account I went with a Weldon. Much more comforting than the Facet. It is warm enough in Georgia that I really never noticed any trouble starting with the Facet though.

[PapuaPilot]

I thought it would be good to follow up on what I have done so far. I was able to get a used Dukes pump where I work. Actually I put one together out of several green tagged pumps that came off of C-185s. I picked the best running motor I could find and mated a very low time pump assembly and got a "like new" boost pump. The nice thing about this pump is that is doesn't require a bypass line and check valve, it is already built into the pump.

I just finished making a mounting bracket and fuel lines from the header tank to the firewall. I kept the fuel line run as straight as possible and put the pump under the right seat and mounted the bracket to the bottom airframe tubes. I ended up buying an aluminum header tank from KF after reading all of the issues with the poly header tank that came with my plane.

I will need to set the correct fuel pressure/flow later on, but this pump should give me got atomization for priming and the ability to keep the engine running should the engine driven pump fail.

I will make a drain line later for the aux pump case drain. I think I will have it come out the bottom at the same place as the header tank sump. This line is one that should not have fuel draining out. If it is dripping you have leakage at the seal of the pump.

[airlina]

Nice job Phil, looks like a good clean setup with the backup pump. I had to have a parallel fuel line with a check valve because my holley didn't have the internal bypass that yours has . My IO-240 installation has 3 drains exiting at the lower mid firewall 1) eng driven case drain if the seal fails (there is a service bulletin to check the integrity of the seal) 2) manifold drain from the spider 3) cylinder drain for overpriming to prevent hydraulic lock. Bruce N199CL