Ultima Fuel Delivery System Flaw?

[anonymous-user]

ROWDYRENAULT said:

what slosh? Through a 1 inch line your going to get slosh? not hardly by the way the blackhawk helicopter I used to fly had a single 2.5 inch connector between the two 180 gallon cells

Not really comparable, as aircraft, (inc helicopters) don't really generate large purely lateral loadings. If you want to translate across the sky, you need to use your wings (fixed or rotary) and that means banking the aircraft keeping the major loading component vertical wrt the airframe.

If you have a large lower pipe, on a track with long high speed corners, fuel slosh WILL be significant, and could be critical at lower fuel loads. The other slight danger which could occur with any of these systems is parking on a cross slope with a low fuel load, with the "pumping tank" on the high side. Hopefully, in that case, where there is plenty of time for all of the fuel to drain out of the highside tank, the volume of fuel in the swirl pot would be enough to allow a start and drive off etc

[skidiiii]

Thanks to all that have posted. I am using Spatz's design keeping both filling ports for now as I have -6 all around. Parts have been ordered and I will re post how the system works after it has been finished. I am moving the swirl pot away from the exhaust where the factory had me place it and moving it on top of the RH tank next to the AC cooler. It will be more accessible there and will be in a much cooler part of the engine bay. Thinking of not re wrapping it with heat shield as I want any heat to dissipate as fuel passes through the pot?? Thoughts anyone.

[spatz]

you will find that on hot days in traffic there is still issues with heat up of fuel, but
that will hardly to be avoided since then all fuel in both tanks is hot.

[UltimaCH]

If people have problems with overheating fuel, has anybody thought of incorporating a cooler somewhere in the fuel system? Perhaps somewhere near a cooler (coolish) air intake, such as in front of the oil cooler or A/C condenser?

[skidiiii]

I have heat shielded both tanks as this will help cut down on exhaust headers being so close to the tanks. A cooler would be a good idea I would just get concerned over time that a leak could develop in the cooler and spell disaster. Anyone try a fuel chiller yet? I think this would be connected right after or before the hi pressure pump.

[crossram]

Fuel chiller 300 USD

[Storer]

I have a fuel temperature sensor on the fuel regulator and have never seen more than 38C at it's highest. The fuel system is under slight pressure so I am not sure what the boiling point would be.

If people are worried about fuel temperature why not fit a sensor so that you know the actual temperature.


Paul

[738 driver]

[quote=Max_Torque]


Not really comparable, as aircraft, (inc helicopters) don't really generate large purely lateral loadings. If you want to translate across the sky, you need to use your wings (fixed or rotary) and that means banking the aircraft keeping the major loading component vertical wrt the airframe.

If you have a large lower pipe, on a track with long high speed corners, fuel slosh WILL be significant, and could be critical at lower fuel loads. The other slight danger which could occur with any of these systems is parking on a cross slope with a low fuel load, with the "pumping tank" on the high side. Hopefully, in that case, where there is plenty of time for all of the fuel to drain out of the highside tank, the volume of fuel in the swirl pot would be enough to allow a start and drive off etc



That would suggest Heli drivers fly "in balance" all the time Max ..... !!!!
... As always ... The fuel delivery debate is interesting ..

[skidiiii]

Thinking more along the lines of adapting this unit. Would swap the tstat to a lower value to activate the fan. IT is intended for oil cooling but pressure tested to 200 psi. Any thoughts?
http://www.ebay.com/itm/B-M-HI-TEK-ENGINE-OIL-AMP-...

[738 driver]

Consistent temp / SG help simplify results .....

[anonymous-user]

skidiiii said:

Thinking more along the lines of adapting this unit. Would swap the tstat to a lower value to activate the fan. IT is intended for oil cooling but pressure tested to 200 psi. Any thoughts?
http://www.ebay.com/itm/B-M-HI-TEK-ENGINE-OIL-AMP-...

Much much better to prevent the heat transfer and resultant upheat in the first place, than have to deal with it via secondary methods. I.E. use a returnless system and heat shield your tanks etc. Frankly, for an OEM vehicle, we regularly see fuel in the rails at well over 100degC on a restart after an extreme engine off heat soak, and we manage to get the engine to start properly under those conditions. The issue for an ultima with it's non sealed fuel system (ie no carbon canister etc) is really to try to keep the bulk fuel temps low to prevent excessive vapourisation in the tanks at partial fuel loads.

[spatz]

you can use a fuel temperature sensor/switch and mate it to a peltier element that you can attach to your swirl pot,
your electric load however will increase.

Uwe

[UltimaCH]

Storer said:

I have a fuel temperature sensor on the fuel regulator and have never seen more than 38C at it's highest. The fuel system is under slight pressure so I am not sure what the boiling point would be.

If people are worried about fuel temperature why not fit a sensor so that you know the actual temperature.


Paul

Excellent idea and real world measurements.

[UltimaCH]

spatz said:

you can use a fuel temperature sensor/switch and mate it to a peltier element that you can attach to your swirl pot,
your electric load however will increase.

Uwe

I had forgotten about the Peltier element. For those with "sparks" expertise, what is the approx draw on the electrics when using one of these?

[F.C.]

UltimaCH said:

I had forgotten about the Peltier element. For those with "sparks" expertise, what is the approx draw on the electrics when using one of these?

Typical 40x40mm Pelletier plate 12v = 4.4 amps

[Justaredbadge]

One of these on each tank outlet will do the job.

http://www.speedflowshop.co.uk/-6-an-billet-alumin...

I do find it strange that there are no filters before the valve block.

[skidiiii]

Does anyone know if there is some type of valve that exists that will be normally open but close when air is introduced? Example left and right tanks linked, fuel level low in a hard corner it would be possible for the fuel from the tank being drawn from for it to loose pressure. Idea being draw from link center of both tanks with some sort of valve that would close if air is detected allowing for the tank with fuel to supply the pump?

[3Dee]

skidiiii said:

Does anyone know if there is some type of valve that exists that will be normally open but close when air is introduced? Example left and right tanks linked, fuel level low in a hard corner it would be possible for the fuel from the tank being drawn from for it to loose pressure. Idea being draw from link center of both tanks with some sort of valve that would close if air is detected allowing for the tank with fuel to supply the pump?

I looked at that a few years ago, when designing my system, but could not find anything suitable.
Should be something though, I would have thought?

[anonymous-user]

Industry sized (ie big!) floating ball valves are availible with a hydrocarbon fuel rating, but they are, er big, cumbersome and are not really designed for use in dynamic situations (ie lots of vibration and some G loading etc)

If you wanted to run with two "separate" but effectively linked tanks, the best method would be to use two pick up pumps, one in each tank, link the tanks at the top with a big pipe (at least 1" with separate "de-air" pipe to filler neck to allow rapid filling) and link the bottom of the tanks with a small pipe (say 2mm dia to allow long term "leveling" of the contents). Return the swirl pot excess to each tank, using a common run that Tees off to each tank (this will require some careful routing to ensure even flow, but that can be negated to a large degree by using a small restrictor orrifice in each line (ie, to ensure that the static pressure in each line is massively bigger than the pressure drop due to geometry and routing etc) Those small restrictors will also help to pressurise your swirl pot to help your main pressure pump!

[deadscoob]

Justaredbadge said:

One of these on each tank outlet will do the job.

http://www.speedflowshop.co.uk/-6-an-billet-alumin...

I do find it strange that there are no filters before the valve block.

They're too small, certainly on new tanks. I had those, kept clogging up so binned them and stuck a larger filter on with dry break couplings so the tanks don't need draining if you need to clean them.