[geeyoutoo]

A rough schematic of the mechanical layout.

 

[kymbo75]

I'm not going to worry about putting a pressure gauge in, the pressure runs at about 6 psi internally controlled and once the spill line return is done there should be no issues. At very high revs it may go into negative territory but that is not really a problem.

Is the spill return line mod really needed to be done with one of these lift pumps, I was just wondering if the pump does fail would the injector pump still be able to suck enough fuel up with this mod done, also if you don't install a check valve can fuel still be sucked through the pump if it is not working.


Any of you guys running a fuel/water separator before the fuel filter, if so what one, or what do you recommend.

Cheers Kym.

 

[425OOT]

A rough schematic of the mechanical layout.

Hi I was just wondering how the 'Y' bypass into check valve will be filtered fuel.

 

[kymbo75]

Hi I was just wondering how the 'Y' bypass into check valve will be filtered fuel.

I think the filter is there just for the lift pump, so it doesn't put anymore strain on the injector pump if the lift pump stops working.

 

[geeyoutoo]

Is the spill return line mod really needed to be done with one of these lift pumps, I was just wondering if the pump does fail would the injector pump still be able to suck enough fuel up with this mod done, also if you don't install a check valve can fuel still be sucked through the pump if it is not working.


Any of you guys running a fuel/water separator before the fuel filter, if so what one, or what do you recommend.

Cheers Kym.

The likelyhood of getting enough fuel through the pump if it failed is basically 0 hence the check and bypass.
That is one of the appeals of the Walbro FRD11 you don't need to bypass, fuel will flow through on a failure, but I have been thinking about this for over a year and ultimately decided on the Carter.
The spill line takes away the chance of filling the engine with diesel as well as acting as a cooling influence.

I think the filter is there just for the lift pump, so it doesn't put anymore strain on the injector pump if the lift pump stops working.

Yes that's spot on, but I'm having second thoughts tonight and wondering whether I really do need a filter there.................

 

[Grogey]

The likelyhood of getting enough fuel through the pump if it failed is basically 0 hence the check and bypass.
That is one of the appeals of the Walbro FRD11 you don't need to bypass, fuel will flow through on a failure, but I have been thinking about this for over a year and ultimately decided on the Carter.
The spill line takes away the chance of filling the engine with diesel as well as acting as a cooling influence..............

Hi geeyoutoo,

Interesting thread. This is my next logical mod.

Why did you pass up on the Walbro FRD1?

and

Can you explain more about the spill line. regarding how it would work.

Cheers

Grogey

 

[Bittsandbobs]

A rough schematic of the mechanical layout.

It could be better to install the primary filter after the lift pump. It is easier for the pump to push the fuel through the filter rather that to pull it through the filter.
If worried about the lift pump sucking in crud, install an inline strainer before the pump. A simple strainer that can easily disassembled and cleaned out.
This makes the primary filter optional, if you are getting satisfactory service life from the main filter.
Also with the primary filter mounted after the lift pump, you have many more options for of location for mounting it.
Cheers,
B&B

 

[geeyoutoo]

Hi geeyoutoo,

Interesting thread. This is my next logical mod.

Why did you pass up on the Walbro FRD1?

and

Can you explain more about the spill line. regarding how it would work.

Cheers

Grogey

When I was in the States I looked at many pumps, Fass, etc etc, and different types including Gerotor, rotary vane and solenoid. It was very close between the Walbro FRD11 and the Carter 4600HP, the up market US pumps were excellent but very large and very expensive, some requiring separate regulators and separate return lines, too complicated.
The flow through the Walbro is 55gph and around 5psi whereas the Carter is 100gph and 7 psi (this is free flow and not what you will get when fitted up), both pumps have no issue pumping diesel, some others the makers shy'd away when you told them diesel was going through them. For all intents and purposes you require 2 x Walbo's to achieve a similar result.
It has taken me a long time to get my head around the spill line mod, but I remember several threads over the years about guy's unknowingly filling there engine with diesel from a spill line leak where it runs under the rocker cover, any increase in the return may just cause a problem and the benefit is a cooler fuel run.

My comment earlier about a prefilter for the pump was just thinking out loud, I'm just not sure..... I'll hopefully get some comment back from some of our learned brethren telling me whether I'm an idiot or a genious.

Cheers

Edit:

It could be better to install the primary filter after the lift pump. It is easier for the pump to push the fuel through the filter rather that to pull it through the filter.
If worried about the lift pump sucking in crud, install an inline strainer before the pump. A simple strainer that can easily disassembled and cleaned out.
This makes the primary filter optional, if you are getting satisfactory service life from the main filter.
Also with the primary filter mounted after the lift pump, you have many more options for of location for mounting it.
Cheers,
B&B

Don't really need a post lift pump filter as the original will do the job it always has (i've had problems with previous diesels and bad fuel but never once in 12 years has my engine light come on for a filter problem, but I have had refills that should have performed better).

I agree that a small throw away filter (but it needs to have 3/8" fittings which I have not found yet) may be preferred, There is not a lot of room under there, spent most of today looking up from under the back and its gets crowded, to the point I'm a little concerned, protection of the hardware from external damage is my primary concern at the moment.

 

[Bittsandbobs]

I have a Walbro fitted to my truck but I would like something with a bit more flow and pressure still for using veg.
On the weekend I came across a mechanical gear pump used as a fuel feed pump for a truck.
I like the mechanical pumps better than electric, You know they are working and they tend to be a lot stronger than the Electrics.

The lift pump on my Merc was unreal. It would Crush blocked filter elements and suck any Vac hose flat. Unfortunately they were lever type pumps driven off a cam and impractically difficult to adapt.

The truck gear pump I'm looking at maybe driving off the back of the fan belt depending on how much it takes to drive the thing. Normally they are gear driven from inside the engine.


That prefilter looks Good.

There are similar types used for marine apps which is where that one is sourced from I suspect.
I got a filter from Bunnings used for irrigation applications. It's a reusable type with 13mm ends fo I was just going to use some Nylon hose adapters to fit it up.
Should have excellent flow.

I have been using the disposable Filters from super cheap.
$3 each and 10 UM rating. They flow surprisingly well and would be more than adequate on diesel seeing I get away with them on Veg.

You can also find electric driven gear pumps. This setup probably requires a pressure relief valve with a return line for the excessive fuel.

Cheers,
B&B

 

[parscheese]

I ran my pump straight from the tank to pre filter, to stock main filter then injection pump.

I don't think it's absolutely necessary to have the spill return and check valve system.

Geeyoutoo check this pre filter out:

Holley Performance Products Oil Filter*230308ERL

I actually bought one but never used it, not cheap but if you find it suits your needs send me a pm and can work out a price.

The only other mod I want to do to my system is install an oil pressure cut out so the pump only runs with oil pressure I.e engine running. I have tested my Carter and the injection pump will draw through it at idle without problem.

Rest of my install pictures coming soon.

Cheers

Justin

 

[parscheese]

Just for FYI:

2.8 GU with a Carter Pump.

Fuel Pressure at idle: 6.5 psi
Fuel Pressure WOT: 3.5 psi

Cheers

Justin

 

[Jocky]

I'm a little confused about the spill line and check valve, where I come from a check valve is a non return valve.

Right you said if the electric Lift pump fails you wouldn't get any flow through the pump feeding the Injection Pump, so you fitted a spill line, to continue to feed the Injection Pump.

1. This is where I'm getting confused, Is the Spill line as you call it, a Lift Pump Bypass line which shows the NRV in, If electric pump fails the Injection Pump Continues to suck, the check valve (NRV) opens and allows diesel to continue to flow to the Injection Pump?

2. To me a spill line is a recycle line, what I mean is the pump discharge flows to the pump suction, stops cavitation if here is no forward flow.

So if I've got it right the spill line is a bypass and not a recycle as an Check Valve (NRV) only works one way?

Only asking not having a pop

 

[geeyoutoo]

I'm a little confused about the spill line and check valve, where I come from a check valve is a non return valve.

Right you said if the electric Lift pump fails you wouldn't get any flow through the pump feeding the Injection Pump, so you fitted a spill line, to continue to feed the Injection Pump.
The spill line is existing hard to see but it is just above the Ip, the mod just alters it's course of flow.

1. This is where I'm getting confused, Is the Spill line as you call it, a Lift Pump Bypass line which shows the NRV in, If electric pump fails the Injection Pump Continues to suck, the check valve (NRV) opens and allows diesel to continue to flow to the Injection Pump?

I agree, in my world also a check valve is a non return but it is more commonly referred to as a check valve on the forum.
Spill line and bypass are 2 different entities. The lift pump bypass as shown in the schematic just allows the IP to suck fuel around the Lift pump by opening the check valve in the event of a lift failure while not allowing the lift pump pressure to let fuel return to the tank when the Lift is operating normally.

The original spill line objective is still maintained it just doesn't flow under the rocker cover any more, keeping fuel a little cooler and not allowing fuel to weep into the engine in the event of an anomaly.


2. To me a spill line is a recycle line, what I mean is the pump discharge flows to the pump suction, stops cavitation if here is no forward flow.

So if I've got it right the spill line is a bypass and not a recycle as an Check Valve (NRV) only works one way?

Only asking not having a pop

No worries mate, it took me a long time to get my head around it as well, See comments above in red.

I ran my pump straight from the tank to pre filter, to stock main filter then injection pump.

I don't think it's absolutely necessary to have the spill return and check valve system.

Geeyoutoo check this pre filter out:

Holley Performance Products Oil Filter*230308ERL

I actually bought one but never used it, not cheap but if you find it suits your needs send me a pm and can work out a price.

The only other mod I want to do to my system is install an oil pressure cut out so the pump only runs with oil pressure I.e engine running. I have tested my Carter and the injection pump will draw through it at idle without problem.

Rest of my install pictures coming soon.

Cheers

Justin

Thanks mate, look forward to the pics. Saw filters similar but smaller at Pirtek, they were around 30/40 micron which I think would be more than adequate for a prefilter. Really we are only trying to stop large rocks and small boys from getting through the LP.

Interestingly while I was at Pirtek buying bits the salesmen said to me, "do you own a Nissan Patrol"? Err yes, why? "because another guy was in here yesterday buying similar bits for his".
So somewhere up here on the sunny coast someone else is going through this mind bender.

 

[whitie]

I ran my pump straight from the tank to pre filter, to stock main filter then injection pump.

I don't think it's absolutely necessary to have the spill return and check valve system.

Geeyoutoo check this pre filter out:

Holley Performance Products Oil Filter*230308ERL

I actually bought one but never used it, not cheap but if you find it suits your needs send me a pm and can work out a price.

The only other mod I want to do to my system is install an oil pressure cut out so the pump only runs with oil pressure I.e engine running. I have tested my Carter and the injection pump will draw through it at idle without problem.

Rest of my install pictures coming soon.

Cheers

Justin

Hi Justin, the spill line is designed and tested to work under vacuum conditions. When you install a small lift pump that does not keep the line pressurised all the time you may get away with it however with the larger flowing pumps, the line is always under pressure and if there is a leak, you will be "making oil" in a hurry...

The check valve is there due to the possibility of the lift pump rotor getting stuck / failing in a spot where it does not allow fuel to flow to the VP44. As you know, the VP44 is fuel cooled so any blockage will kill the IP - in this case, the mod is there to ensure that the VP44 will live even after a catastrophic lift pump failure.

Cheers

 

[parscheese]

Hi Justin, the spill line is designed and tested to work under vacuum conditions. When you install a small lift pump that does not keep the line pressurised all the time you may get away with it however with the larger flowing pumps, the line is always under pressure and if there is a leak, you will be "making oil" in a hurry...

The check valve is there due to the possibility of the lift pump rotor getting stuck / failing in a spot where it does not allow fuel to flow to the VP44. As you know, the VP44 is fuel cooled so any blockage will kill the IP - in this case, the mod is there to ensure that the VP44 will live even after a catastrophic lift pump failure.

Cheers

Agreed. That's why I have fuel pressure gauge to monitor everything. I also have my by pass hose kit in case of pump failure. Not "ideal" for everyone but that's my back up.

I basically ran out if room to fit the extra plumbing for the bypass.

Cheers

Justin

 

[geeyoutoo]

Agreed. That's why I have fuel pressure gauge to monitor everything. I also have my by pass hose kit in case of pump failure. Not "ideal" for everyone but that's my back up.

I basically ran out if room to fit the extra plumbing for the bypass.

Cheers

Justin

Therein lies my issue, I want to protect the pump from external damage but I want to be able to get at any part of the system as easily as possible under difficult circumstances, like being halfway down the Gibb River Road at the end of the wet season, and I don't want to physically cut any part of the existing fuel system. As said to a friend this morning I have not had the engine light come on for fuel reasons in the 12 years I have had the Troll, I have on previous diesels and I'm much more careful about fueling now.

So as of this morning prefilter is now out, bypass stays for sure but am looking at different slow 90 bends for the pump outlet to further compress the fitment, not a fan of 90 std brass fittings in this case unless they were well oversized to cope.

Thinking about a gauge purely for reference T'd at the IP filter outlet along with a bleed point. The idea re the oil pressure switch has good points, read about some in research so still thinking about that, but it can be done at any time in the future, so no biggy

Next step will be laying under vehicle again producing Cunning Cardboard Cutouts.

My wife has given up talking to me as I have been constantly looking into space deep in thought.

 

[parscheese]

My set up should have plenty of room without the pre filter.

Might add that access is very good.

Mine is 100% protected that I'll bet any body part on.

Cheers

Justin

 

[kymbo75]

My wife has given up talking to me as I have been constantly looking into space deep in thought.

Yer that happens to me too

 

[parscheese]

Pictures as promised

Underneath access hatch open position:

Access hatch closed position:

Side view behind LHR wheel. Bolts holes for pump mount South Co SS latch:

Mount bolted on to fuel tank protection plate: (before powder coating)

How it all fits in:

Back of car to right of picture looking towards right hand side of car.

How it bolts to the tow bar at the back of the bracket. Note the heavy RHS that is for the rear protection devices.

Please note: there is likely more room towards the right hand side. My Patrol has these dodgy welded on rear protection devices which limited room. Didn't have the motivation to remove them at the time but with out them lots more room with the same basic design.

Cheers

Justin

 

[geeyoutoo]

Thanks, after looking at your original pic I thought your setup was something like that, very impressive, I like it.

Mounting the pump to the bracket makes a lot more sense than trying to find a place to mount it and then protecting it.

Good work, I will borrow some of your ideas on that.