IO-360 Boost pump choice

I am uncomfortable with Vans RV7 fuel pump solution for the IO engines. Too many items/connections right below your knees for my taste.
Has anyone mounted their fuel pump in a wing root or some other configuration that creates less connections inside the cockpit? I am also looking for alternatives to the Aiflow performance setup. What other pumps are being used?

Regards

I agree but used it anyway

So far the Airflow Performance system from Van's works fine on my IO-360. It does have lots of bends and connections but they are all in a nice package that is removable to work on. The cover over the top and a drain hole in the lower fuselage just forward of the spar keeps it all confined and out of the immediate cabin area. I could not think of a better package and location to put it.

Not sure its a knee knocker issue

I have a fuel pump, filter, pressure relief valve in each wing root.

I do not use the mechanical fuel pump.

The pumps I used are from Napa for about $130 each.

To switch tanks I simply turn on both pumps and turn off the one I don't want. (independant wiring and switches for each pump)

I run both pump sets ofr TO and landing. Replumbed the standard Vans brass valve to on/off operation...I.e no fuel selector.

Worked great for 227 hours.

I had to fit flop tubes in both tanks to get the who ensemble to fit. But it does fit very well.

Let me know if your serious and I'll send you pics, pump model numbers etc.

Frank
7a IFR 227 hours

Other Boost Pumps for FI

You can use a Weldon boost pump model 8163, or a Dukes pump.

Don

Wow, the man's telling you what to buy if you don't want to buy HIS. That's pretty good service... and you aren't even a customer.

Karl

I bought my Dukes Pumps from John Harmon for both my planes.

don't know if they work better but I didn't want the Van's set up either.

I have some picts in my photo dump in my profile.

Presure and flow?

Thanks guys,
Don your a class act, thanks for the input. What I am considering is a single pump and filter assembly in my left wing root. I have a flop tube in that side so I may have the space. I'm sure the components in Vans package are top notch. What I object to is the number of connections inside the crew compartment. Tubes tend to fail where they connect to other objects (look at the brake line issues). While Vans setup is short runs and much less prone, why put them there at all?
I.E. Single tube from rt and lt tank to selector. selector return line to left root, pump/filter/checkvalve, presure valve, in wing root, single line on left wall to FW.
The total connections in the crew compartment would be much lower.
This also clears the way for the center to hold O2 or a fire extinguisher without the thought of the main fuel line underneath.

The dual Napa is interesting from a redundancy point although I would not consider eliminating the mechanical pump. Cost would also be a wash so the question would be what is safer? A single AFP or dual automotive?

Dual electric pumps

While dual electric pumps are one solution, there is more to the installation than two $130.00 pumps. There is a check valve and relief valve for each pump and the additional plumbing for the return line back to each tank. If the engine driven fuel pump was used, the installation would require a bypass check valve around each pump to allow free flow to the engine driven fuel pump when the electric pumps were off.

There are lots of options out there.

Don

Options

Thanks Don,
I know I have more research ahead. I am planing to use the same structure as supplied by vans right now. Just a different physical layout.
BTW: I used to live in Spartanburg years ago and work in Greer. Are you at the airport heading towards Greer?
Living in LA sure makes you miss the green of the SC mountains.....

Regards

Locaiton Location Location

Don't locate the pump on the firewall where a tall person could break the plastic pump housing behind the rudder by putting their foot on the fuel line and pushing real hard.

Ask me how I know.

Dale Lambert
RV-6 builder
RV-7 flyer

pumps

Check with Airperformance in the mid west. They design for the air racing industry. My pump package came from them.

Don at Airflow said:

While dual electric pumps are one solution, there is more to the installation than two $130.00 pumps. There is a check valve and relief valve for each pump and the additional plumbing for the return line back to each tank. If the engine driven fuel pump was used, the installation would require a bypass check valve around each pump to allow free flow to the engine driven fuel pump when the electric pumps were off.

There are lots of options out there.

Don

Click to expand...

I'm confused, in some postings I read that you don't need a return line back to both tanks and in others (the one above) I read that you do????

jdeas said:

I am uncomfortable with Vans RV7 fuel pump solution for the IO engines. Too many items/connections right below your knees for my taste. I am also looking for alternatives to the Aiflow performance setup. What other pumps are being used?

Click to expand...

Andair seems has a much simpler solution. See this thread http://rivetbangers.com/forums/viewtopic.php?t=3278 for more info and pictures to compare Vans setup and Andair's. I'm thinking Andair at this point for my build.

I went with the Andair pump, valve and filter. Seems to be a good installation. I bought direct from Andair on their web site and had it within a week. They had a great RV package deal after Oshkosh.

Jay Erickson, RV-7A finishing kit UT47 Hurricane, UT

jdeas said:

I am uncomfortable with Vans RV7 fuel pump solution for the IO engines. Too many items/connections right below your knees for my taste.
Has anyone mounted their fuel pump in a wing root or some other configuration that creates less connections inside the cockpit? I am also looking for alternatives to the Aiflow performance setup. What other pumps are being used?

Regards

Click to expand...

Ouch!

Nearly a grand for the pump?....you can buy the same thing from napa for 130 plus about 25 I think for the valve. The filter will cost another $80. $200 for the whole thing sounds a lot better to me.

No Frank, that price includes a fuel selector valve, filter and bulkhead fitting.

If you compare prices, it is a tad higher than Airflow Performance's pump from Van when you include the cost of the Andair valve (should you choose to add that).

I got the show special price of $950 at OSH.

The install is very straightforward. Bolting it in now. I will have pics soon!

CJ

Weldon here...

I used a weldon when I converted to FI, you can see a pic of it under the rudder pedals on the panel upgrade picture I posted (click on the picture currently on the front page). Proven pump design and no box between the seats. Inline flow-exy filter installed between the seats right after the selector which required just a small cutout in the center cover for clearance.

I just re-read this.

jdeas said:

Thanks guys,
Don your a class act, thanks for the input. What I am considering is a single pump and filter assembly in my left wing root. I have a flop tube in that side so I may have the space. I'm sure the components in Vans package are top notch. What I object to is the number of connections inside the crew compartment. Tubes tend to fail where they connect to other objects (look at the brake line issues). While Vans setup is short runs and much less prone, why put them there at all?
I.E. Single tube from rt and lt tank to selector. selector return line to left root, pump/filter/checkvalve, presure valve, in wing root, single line on left wall to FW.
The total connections in the crew compartment would be much lower.
This also clears the way for the center to hold O2 or a fire extinguisher without the thought of the main fuel line underneath.

The dual Napa is interesting from a redundancy point although I would not consider eliminating the mechanical pump. Cost would also be a wash so the question would be what is safer? A single AFP or dual automotive?

Click to expand...

The dual wingroot pump is not motivated by redundancy..Rather the mechanical pump is hydraulically flawed and the wingroot system corrects this...I.e the mechaincal pump is in the wrong place.

it is also difficult to make a dual wingroot system work well with a mechanical pump..i.e it you have to consider the mechanical pump will suck air from an empty tank, where as the electric wingroot system avoids this,..i.e the pump cannot pump air and overcome the other pump that is pumping fuel...I wouldn't go there if I were you.

The automotive pumps are no less well made than the "proper airplane pumps"..I.e they are essentially the same. I.e the airplane pumps are automotive and very reliable, but they all suffer from a few infant mortaility failures like anything else. It seems if they survive 50 hours they will run for thousands..I'm paraphrasing Don here.

I think you could put the single pump (with mechanical pump) in a wingroot but you would be better off maintining the same architecture of the standard system..In this case you probably just want to plumb the electric pump to say the left wing tank and take off/land on the left tank.

Frank

The Andair kit is ~ $820 direct.
The weldon pump is $633
The Vans setup is $635

I'm thinking the Vans setup is the way to go but not if I have to have return lines to my tanks. The Andair doesn't require return lines and is self priming to 10 ft..

The Andair looks extremely simple (1 line in 1 line out):

http://www.andair.co.uk/pdfs/RV7-installation.pdf

as opposed to the Vans:

http://www.vansaircraft.com/cgi-bin...2267-402-45&browse=engines&product=fi-install


Anyone know what the Andair controller does?

Maybe I'll just go with a carb. to save the headache and $3K.

Frank,

The Andair motor is a brushless DC motor. It is cooled by the fuel that flows through it. They export the "brushes" electronically to the controller so there is no arcing inside the motor (where the fuel is).

Does that help?

CJ

It depends

Captain_John said:

Frank,

The Andair motor is a brushless DC motor. It is cooled by the fuel that flows through it. They export the "brushes" electronically to the controller so there is no arcing inside the motor (where the fuel is).

Does that help?

CJ

Click to expand...

On if a brushless DC motor is anymore reliable than a brushed motor..I honestly have no idea on whats inside mine..When these things fail is it due to the motor or the rolervane wearing out in the pump?..Whats the starting torque characteristics of a brushless motor? If the pump is a bit sticky does the high inrush current of a stalled brushed motor to get it unstuck exist in brushless?

I honestly don't know the answers to these questions and I'm sure it is a very fine pump but it may be no better than a standard automotive pump like that is found on any other airplane.

If you think you think the downsides of long delivery are outweighed by the pump's postive attributes then by all means go for it.

Frank

Oh

Arching inside the motor from brushes is not issue in the oxygen free environment...I must admit it doesn't sound great but pumps don't burst into flames just cos the motor is immersed in fuel.

Frank

Thats funny

briand said:

Maybe I'll just go with a carb. to save the headache and $3K.

Click to expand...

Ahh but the advantages of LOP opeartions will eventually pay for it..Oh and you can fly upside down with FI and a few other expensive toys..

Frank

frankh said:

Ahh but the advantages of LOP opeartions will eventually pay for it..Oh and you can fly upside down with FI and a few other expensive toys..

Frank

Click to expand...

I know, I know, I will probably go with the FI. Don't forget about NO carb ice.

Don at Airflow said:

While dual electric pumps are one solution, there is more to the installation than two $130.00 pumps. There is a check valve and relief valve for each pump and the additional plumbing for the return line back to each tank. If the engine driven fuel pump was used, the installation would require a bypass check valve around each pump to allow free flow to the engine driven fuel pump when the electric pumps were off.

There are lots of options out there.

Don

Click to expand...

I am considering a fuel management system that uses a low pressure transfer pump mounted in the right wing root to pump fuel from the right tank to the left tank, and a high pressure boost pump/filter mounted in the left wing root to feed the mechanical pump. No fuel tank selector valve is required, just an on/off valve. This system meets the goals of minimizing fuel system components/connections within the cockpit. Service of fuel pump and filter are performed external to the cockpit. (Grey hair has brought reduced appreciation for the smell of 100LL in the cockpit, and I certainly want Babydoll to enjoy the ride,too.) Fuel system management becomes a matter of turning the transfer pump on and off at appropriate times, a task perhaps marginally more difficult than switching a tank selector valve. This appears to be a simple, safe, robust, inexpensive, clean solution to the dual tank issue. Appreciate any insight or experiences related to this concept.

- Roger

Issued just addressed IO320

After several projects viewed 9A's The way to go is ANDAIR control valve from Vans and I just signed up for the group BUY for the ANDAIR pump and filter. VANS Airforce has a site to sign up before DEC 31 2009. Simple, 2 lines in to control valve, one out to FILTER and out the other end of PUMP to firewall. See website for ANDAIR.. I wish it was easier for carb installations.

return lines

Ron, good idea. I'm about to sign up for the Andair group buy. One question. How does this setup with Andair pump/filter and selector, handle fuel return? Are retun lines used? Where does un-used fuel go? I plan to buy Van's IO-360 engine. I already installed return lines in wings. I don't mind not using them if they aren't needed. Do they just get capped off? Does the engine have just one input for fuel?

Why Fix Something that Is Not Broken?

RKellogg said:

I am considering a fuel management system that uses a low pressure transfer pump mounted in the right wing root to pump fuel from the right tank to the left tank, and a high pressure boost pump/filter mounted in the left wing root to feed the mechanical pump. No fuel tank selector valve is required, just an on/off valve. This system meets the goals of minimizing fuel system components/connections within the cockpit. Service of fuel pump and filter are performed external to the cockpit. (Grey hair has brought reduced appreciation for the smell of 100LL in the cockpit, and I certainly want Babydoll to enjoy the ride,too.) Fuel system management becomes a matter of turning the transfer pump on and off at appropriate times, a task perhaps marginally more difficult than switching a tank selector valve. This appears to be a simple, safe, robust, inexpensive, clean solution to the dual tank issue. Appreciate any insight or experiences related to this concept.

- Roger

Click to expand...

Roger, I would be very careful about redesigning the fuel system, this can have fatal consequences.

Here is the biggest problem I see with the fuel system you describe:
An inadvertent activation of the transfer pump causes you to dump half your fuel out the vent.

Also, there is goodness in standardization, what if some other pilot than yourself is flying? They may have a harder time managing the non-standard fuel system than you.

By the way, I never smell fuel in my cockpit despite lots of fuel lines and connections.

Hans

i'm renting a da40 diamond star tdi regularly which has exactly this kind of fuel system setup. (with the addition of a return line that returns to the right tank with a constant flow)

although different, it's not any more complicated what the operation is concerned. the most common mistake is forgetting about the transfer pump on and ending up with an asymmetrical fuel load (which reduces over time because the thielert tdi returns back to the right tank)
instead of switching tanks as in a traditional setup, you turn the transfer pump on and off. operationally an easy change.
however, techically it's not that simple after all.

- the fuel transfer pump needs an auto-shutoff when the left tank is full, otherwise you risk pumping good fuel overboard, as has been mentioned.

- half the total amount of fuel/right tank becomes dependent on the electrical system and/or transfer pump unless you include a backup fuel selector (as has the da40 for this case, cancelling your perceived advantage of less connections etc...).
a traditional fuel system is completely independent of the electrics (except for the boost pump which doesn't necessarily need to be on).

- you would effectively go from 2 separate tanks to a single tank system what the fuel content is concerned. this is an unnecessary sacrifice of redundancy IMHO. if you have a blocked pickup, water contamination or something like that, switching tanks in a "standard" system may solve the problem shortterm. not in your setup.

now, unless you have specific reasons to do it that way, i would highly suggest to stick to the "traditional" basic setup. valid mods IMHO are the dual electrical pumps in the wingroot/tank area and/or a fuel return line with a dual selector for potential auto-fuel/future fuel capability.

the da40 by the way uses this setup mainly for 2 reasons:
- fuel temperature management. the diesel/jet-a1 that returns from the engine is relatively warm and can cool off in the right tank, while fresh fuel is drawn from the left tank.
- no interrupt feed. the high pressure common rail pump on the tdi needs a constant and uninterrupted fuel feed. "running a tank dry" on it even once requires major teardown/overhaul of the engine driven fuel pump. and the single tank setup makes it easier to use at least all fuel in the right tank and having a constant supply to the engine. the backup fuel selector is only for emergency use in case there are no electrics for the transfer pump/the transfer pump fails and then one can switch (rapidly) directly to the right tank.


my 20cts,

kind regards,
bernie

Thanks for the helpful reply. Last weekend I installed a fuel system that is essentially "conventional", except that the gascolator, filter and boost pump are mounted in the right wing root. Looks like this will make filter service a simple task, external to the fuselage, and will keep the mess/smell of spilled gas at filter service out of the cockpit. Gascolator drain valve is adjacent to the right tank drain valve. ( I came to essentially the same conclusion that you recommend, for many of the same reasons). It looks like there might be approximately 22 cm more tube length in this system than "conventional". Operation is "conventional" with a tank selector valve, and a boost pump switch. Shouldn't confuse those other pilots.

FWIW, I do not believe that all of the best soulutions have been implemented yet. And, of course, I recognize the risks associated with flying a poorly thought-out aircraft and make every effort to avoid accident/injury/insult/shame. There are lots of ways to fly "conventional". One of the joys of building an experimental home-built is the freedom to think "new/better" thoughts, even if you implement "conventional" at the end of the day. Thanks for taking the time to consider and reply!

briand said:

I'm confused, in some postings I read that you don't need a return line back to both tanks and in others (the one above) I read that you do????

Click to expand...

It is a matter of operator simplicity. If the fuel selector is 6 port, fuel will return to the tank that is selected to feed. If fuel is returned to a single tank, (4 port selector) the pilot must manage return fuel to that tank so as not to over fill it while feeding from the other tank. The fuel being bypassed to the tank is constant as that is how pressure is regulated in a high pressure injection system. Fuel being returned to a single tank does impose a considerable fuel management work load on the pilot.

With Andair, all this is mute. Andair does not recycle fuel back to a tank but circulates it within the pump. It is a very simple straight forward design, sort of like a cat's meow. The only unknown about it is how much the recirculating fuel within the pump will increase in temperature on a very hot day.

The mechanical pump on the engine is a good news, bad news situation. The good news is it will delivery fuel to the controller without electric power on the aircraft, the bad news is it's intake is a low pressure high temp area and subject to vaporization when the electric boost pump is off.

As a matter of procedure, I turn the electric pump off when out of a 1000' and so far the mechanical pump has not faltered, even on very warm days. But this is with a parallel valve engine, with higher HP or a 6 cylinder there is much more heat to deal with in the pump area.

Any way one decides to go with the fuel system, there are compromises. With 2 electric pumps and no mechanical pump, 2 batteries should be designed into the electric system. If one goes without a fuel return line (Andair), fuel temperature at the pump on a hot day may be a factor. With the pump on continuous it would not matter, fuel under pressure has a much higher vaporization limit. It's when the pump is turned off and the mechanical pump sucks that warmed up fuel forward that the matter will be tested.

Correct..another approach to electrical redundancy is to use a single battery and two alternators...that's the way I chose but either way can be made to work. It's no more complexity if you are building such redundancy to fly IFR for example.

Frank

RV-8 Fuel Pumps & Firewall

I designed my own fuel system:
From tank selector valve to firewall: A metal-flex rubber tube (approved for fuel), to the Firewall. On front side of Firewall alu-tube to an Andair filter/strainer/draincup (75 micron), then alu-tube to Andair Electrical fuel-Pump. Then the FW-fwd supplied hoses to Mechanical pump on engine, then hose to in-line filter from JEGS (35 micron) on engine mount, then to Injector etc.
I did not want all those potential leaks from fittings in the cockpit fwd of L Gear-Tower. Expect to change tube every 5 years.
Has not flown yet.
Any comments guys?

TOM.DK

TOM.DK said:

I designed my own fuel system:
From tank selector valve to firewall: A metal-flex rubber tube (approved for fuel), to the Firewall. On front side of Firewall alu-tube to an Andair filter/strainer/draincup (75 micron), then alu-tube to Andair Electrical fuel-Pump. Then the FW-fwd supplied hoses to Mechanical pump on engine, then hose to in-line filter from JEGS (35 micron) on engine mount, then to Injector etc.
I did not want all those potential leaks from fittings in the cockpit fwd of L Gear-Tower. Expect to change tube every 5 years.
Has not flown yet.
Any comments guys?

TOM.DK

Click to expand...

Fuel pumps, gascolators and aluminum tubes FWF make great heat sinks, last thing you want to do is heat the fuel prior to the mechanical pump.

Yes i have to agree..Sounds similar to the Eggenfelner Subaru system (but they use two electric pumps North of the firewall)..Several "unexplained power loss crashes"...Of course its vapour lock but you can never prove that because the evidence has always gone away by the time anyone goes to investigate.

This is far worse from a VL lock perspective than the original van's systems..which at least has the electric fuel pump in a cool location..i.e South of the firewall.

Sorry to be blunt but a fuel pump North of the FW really is asking for it..maybe not today or next week but sooner or later your fuel; pressure will mysteriously go to zero and the big fan will quit making power.

TOM.DK said:

I designed my own fuel system:
From tank selector valve to firewall: A metal-flex rubber tube (approved for fuel), to the Firewall. On front side of Firewall alu-tube to an Andair filter/strainer/draincup (75 micron), then alu-tube to Andair Electrical fuel-Pump. Then the FW-fwd supplied hoses to Mechanical pump on engine, then hose to in-line filter from JEGS (35 micron) on engine mount, then to Injector etc.
I did not want all those potential leaks from fittings in the cockpit fwd of L Gear-Tower. Expect to change tube every 5 years.
Has not flown yet.
Any comments guys?

TOM.DK

Click to expand...

I'd echo what others have said on electric pump location, though I must admit on my rv-3, the PO ran mogas, I ran both mogas and 100LL and no observed vapor lock... but safer with the pump elsewhere. Tom, I see you are in Denmark. So what fuel do you plan to use? I've read some about a European no lead, maybe 94UL as I recall? I'd think if that is what you plan to run, the vapor pressure and distillation curve of the fuel would be good to know for the purposes of evaluating risk. For me, I think having fittings inside the cockpit seep would be an inconvenience (open every vent and land). I'd much prefer a temporary stink over a surprise up front.
As far as aluminum tubing forward of the firewall. I'd suggest a search of the forum. There are some good threads on fuel lines. Vibration and failure is a concern with the aluminum.