Fuel tank Selector

[KGTM]

For those that the use fuel tank selector, what brand do you use? I need one that can be used with pressurised tank.

I used Pollak 42-159, good for 65 PSI, noticed it leaked a bit so I replaced it but want to see if there is a better one out there.

Thanks,
Mostafa

[KGTM]

Any ideas any one?

[crash]

I wasn't involved in this particular detail, but we use an electric valve that is designed for an aircraft. Our system is likely a bit different than yours as we not only select which tank to supply from, but also to return to. IIRC we used the above mentioned valve but had to make up some machined parts to get the entire system working properly. The oring seals were a little finnicky about the pump gas versus aircraft fuel. I believe we had to change those out. Might want to try McMaster Carr?

[KGTM]

Thanks Crash for response. the valve I have also has return line but I do not use them. do you have a Part number for one you used? just wonder the cost?
I put a new one in and it is fine, the instruction for this valve say do not use for application where will not be use for 6 months or more, may be this was the cause
.
Fuel was all in connector are.

Mostafa

[crash]

Sorry, I looked through my emails as I know we discussed this as a team back in 2014 or so, but I did not find any part numbers. As I said, I was not the point man on this particular system. The part is buried up on the firewall so pretty hard to get to. Might also want to try Aircraft Spruce as a possible source?

EDIT: Just looked on Aircraft Spruce website. All they offer is manual switches.

[crash]

Here is a company whose pumps we use for transmission fluid cooling...

https://www.weldonpumps.com/

It appears they also offer some valves for aircraft. I would give them a call as they have been very helpful to me previously.

[KGTM]

Thanks Crash, I sort of have a new idea that might work withput fuel selector valve.

Just planning to test two one way valve into a Tee going to block, this should work as I only turn on the tank that needs to pump fuel, so this should direct the fuel the corrrect way, the pump does have one way/regulator, but these are 500psi Brass for fuel one way valves.

any reason this will not work?

Mostafa

[crash]

That is a pretty standard way of doing multiple tank setups and I have always used one way valves so that there is no back feed through the pump that is not operating. That said, the issue comes in on the return. Some run a dead head fuel rail type of design in which case you don't have a return. Simple is always better, but our fuel system on the PDG GTM race car is way more complex because of the use of low pressure lift pumps and then a mixing pot and dual high pressure pumps after that. Basically we have two tanks AND we have two separate fuel systems for redundancy on the endurance based GTM.

[KGTM]

I also have two tank and two pump(one in each tank), but no need for return. I should have thought of this before I bought the new valve and replaced it, now I will doing it again, but hopfully will not have to worry about leak as much.

Mostafa

[KGTM]

Hi Crash,

now that I use a one way valve from each tank, I notice that fuel rail pressure goes high after turning engine off when is engine is hot, which sort of make sense since full is hot and there is no return to tank since i use in tank fuel pump, is this an issue? also the fuel rail stays pressurized for a long time which is not bad but high fuel pressure bothers me.

With my hardware control I can just turn the pump of and then turn car off few seconds later and burn the fuel, but like to know what you all think if I do not do any thing.

Thanks,
Mostafa

[crash]

Well, on the plus side that higher pressure may keep the fuel from boiling in the rail like it might if the rail is hot and the pressure goes to zero because of back flow through the pump when it is turned off. I don't think it should be any issue. Even if pressure is high at start it will come down, likely, in under a second of running, maybe even during cranking. As long as the pressure isn't going WAY high to where you may have a line rupture, then it should be fine. Probably just the pump running for a split second or so when the ignition is turned off that is causing the pressure rise.

[KGTM]

This only happens when engine is hot, otherwise the pressure stays right about 56 psi after turning the engine off,my fuel pressure sensor goes to limit about 110 PSI. so do not know how high it actually is, but I can see it could go high as the fuel expand and has no place to go and will no compress like air.

if fuel line pressure is high after the valve then weather the pump is on of off does not matter since the valve are closed anyway due to negative pressure, and fuel is return to tank.

Thanks,
Mostafa