Fuel lift pump pressure

[hala]

Anybody knows what pressure the ordinary mechanical fuel lift pump deliver for i.e. 6245 ? My guess is about 14 psi??
Hazze

 

[hve]

I do not have any data on the Zetor , but an old fashioned, 60's-80's car, mechanical petrol pump typically delivered 7psi and the electric diaphragm ones only deliver about 3psi
Facet pumps about 5psi standard or 10psi for high performance applications.
i doubt the zetor pump would be much more than 7psi.
but easy enough to put a gauge on it.

Really not critical to have much pressure on the feed, as long as you can get volume to the injector pump (after the filters) it will do the rest ..... it is a pump after all,
My Ford 4000 tractor has no lift pump at all, just gravity from the tank!

 

[dave_peters]

My Ford 4000 tractor has no lift pump at all, just gravity from the tank!

But it does have a DPA pump with a vane pump in the end !!!

 

[hala]

Steve not having a liftpump on the 4000, is it standard or special for yours because on my friends there is a mechanical one?
I messured the spring force and the piston area on a Zetor liftpump and calculated the pressure to 12 - 14 psi. Why I wondering is because a friend has asked me to install a electrical pump on his 6245 and I have to find out what type of pump I will go for. Any recommendations?
Hazze

 

[hve]

Steve not having a liftpump on the 4000, is it standard or special for yours because on my friends there is a mechanical one?
I messured the spring force and the piston area on a Zetor liftpump and calculated the pressure to 12 - 14 psi. Why I wondering is because a friend has asked me to install a electrical pump on his 6245 and I have to find out what type of pump I will go for. Any recommendations?
Hazze

Yes Standard on the Ford 4000 3cyl Diesel with Rotary pump, the Ford 3000 with in-line pimp did have a low pressure lift pump.

I do not think the feed pressure will be critical, anything from 3-15psi would suffice, .......... all you need to do is get Diesel to the injector pump (without any air)

Are you just looking to provide positive feed to the existing pump to flush out air and prevent backflow? if so then 3psi is fine.

If the electric pump is going to bypass the existing pump all-together then go for a 5+ PSI pump to have enough pressure to push the diesel through the filters. (more viscous than Petrol!)

Diaphragm pumps are most suitable for the first option, as they prevent any bleed-back and switch off when there is pressure ahead of the pump, however most electric Diaphragm pumps will not go above 3psi.

Shuttle pumps (such as Facet, and various copies) can reach as high as 5psi maybe 7psi and will out perform a diaphragm pump on Flow, but some designs do allow bleed-back through the pump. (test by blowing into the outlet
I had a Facet pump feeding a Nissan 2.8L Diesel Turbo (160hp) engine in a Land-rover and it worked well.

Next option is a Rotary pump, usally start at 7psi minimium and will flow about double the Facet, however there is no back flow prevention, and they are not self priming so would need to be mounted lower than the tank, not an easy task with an undermounted tank.

Cheers

Steve

 

[hala]

Thank you Steve. Most appreciated.
Hazze

 

[hve]

Any time
do let us know how it all works out
Cheers
Steve

 

[hala]

Anybody knows how much fuel that is bypassing to the tank i %? Say if a 4 cyl. consuming 12 l/h how many % of the total flow is that (between thumb and forefinger) . A rough guess is good enough as I will use it as a guideline to dimension the electrical pump.
Hazze

 

[hve]

Size the pump to twice the max usage of the engine and you will be safe