F5000: Info on fuel pump setup of Lola T333 needed

[eugen]

A question for the experts out there: on my recently bought Lola T333 (the "John Morton car") I have this rather complicated fuel setup - see picture.
1) is an electrical fuel pump, (2) is a belt driven fuel pump. (4) could be a filter and (3) is a little tank. And a lot of fuel lines that finally lead to the quad-carb (no fuel injection).
I want to understand it. Is that a usual setup? Do I need to have the electrial pump running all the time?

Thanks for any insight on this.

greetings from Austria...............Eugen

[10rmotor]

This looks very similar to the fuel system I have on one of my DSRs. I don't know how yours is routed but this is mainly for fuel surge to get every drop of fuel before it dies. One pump fills the small tank which hopefully stays full until the fuel tanks get close to empty and the second pump sucks out of that small tank and feeds the carbs/fi. I would think this setup is more for fuel injected cars that don't have a fuel bowl and can't handle sucking air. Injection doesn't like air.

[billtebbutt]

Guessing....

Somewhere in that set up there would need to be a pressure regulator - I think that is #4. #3 looks like a large fuel filter to me. As to why there are two pumps I can dream up a couple of scenarios:

1. The electrical pump is there to add volume so that the carb doesn't run dry on long, high RPM straightaways. We had this issue in my FA (I know the BDA/Weber is a different beast that what you are dealing with) - the fix in the day was to add a deep spacer to elongate the Weber fuel bowl/increase the capacity. But in your application, that mechanical fuel pump is going to be spinning really fast at full chat, so as long as the pulley sizes are correct and the mechanical pump is in good shape why would the carb run dry??? I'm not buying this

2. The electrical pump is there to prime the carb prior to starting. Otherwise, you'd be cranking that big motor over to build up pressure the fill the carb after the car has sat for a while. And maybe at cranking speed that belt-driven pump just isn't spinning fast enough to quickly prime the carb.

I think #2 is most likely the case, but it would be very easy to prove it out. Empty the fuel bowls in the carb. disconnect the electrical pump and see how long it takes to start off of just the belt-driven pump. Then empty the carb bowls again, connect the electrical pump, turn it on for a few seconds and then see if the car starts more easily/quickly.

On track, run with both pumps and get a baseline. Then turn off the electrical pump and see if there is any difference on track - do not continue to run the motor if it is running out of fuel/leaning out!!!!! (On something that spendy, I'd certainly have a EGT sensor hooked up to a gauge on the dash - easy and cheap to do). If you want to get really cute, do a plug cut after running both pumps - then repeat after the electrical pump is turned off. That should tell you what you want to know

Again, I am only guessing. But let us know what you find out!

cheers,
bt

[J Leonard]

It's all left over from running an old mechanical fuel injection system. Hilborn possibly. For F.I. electric to get started then switch to belt drive.

[Lee Johnson]

It's all left over from running an old mechanical fuel injection system. Hilborn possibly. For F.I. electric to get started then switch to belt drive.

Also very similar to the fuel feed setup for Lucas mechanical (timed) fuel injection.

[eugen]

Thanks for all your valuable information! I also think this are the remains of the mechanical fuel injection, but I wonder, when they built the new engine in 2018, why did they leave it installed. I am also thinking the electrical pump could be for starting only.
And yes, there is a pressure regulator near the carb. I have a fuel pressure gauge in the Lola, so I will try to switch of the electrical fuel pump when testing the car and watch the fuel pressure. The Lola has no alternator, so saving some electrical power is probably not a bad idea.
Or it is how 10rmotor writes it - that is quite a usual setup for racing (I had that in another racecar but with 2 electrical pumps).
There is a crazy amount of fuel lines there with t-fittings and the little tank has also several connections - so I am not able yet to grasp how that works.

Unfortunately the seller of the Lola is sick, so he cannot be asked about these details. On the steering wheel he had a big white duct tape with "pump" written on it (see photo below) - either it was to remind him to turn the pump on or off. :-)

thanks, best wishes...........Eugen

[J Leonard]

If pump 1 and 2 are fed from tank 3, what fills tank 3? This March has Hilborn injected Chevy with the two pumps. Electric just to start and belt drive to run.

[eugen]

Thanks, probably one of these pumps feeds the little tank. But there are really many fuel lines with t-fittings in the system so hard to tell how that really works. The little tank has also several lines running to or from it and is connected to the fuel crossover line between the 2 tanks. Without knowing how the little tank is "wired" internally it is impossible to understand this principle for me.

If pump 1 and 2 are fed from tank 3, what fills tank 3? This March has Hilborn injected Chevy with the two pumps. Electric just to start and belt drive to run.

[Darryl Wills]

Mechanical fuel injection is metered by bleeding volume back to the tank with a jet pill. It looks like a pill box on top of the front of the motor. That could be one of your lines back to the little tank.

edit * NVM..Lee's post is more accurate. What I thought might be the pill box is the back pressure valve. The OP system is definitely a timed system not the constant flow system I am more familiar with.

[Lee Johnson]

Thanks, probably one of these pumps feeds the little tank. But there are really many fuel lines with t-fittings in the system so hard to tell how that really works. The little tank has also several lines running to or from it and is connected to the fuel crossover line between the 2 tanks. Without knowing how the little tank is "wired" internally it is impossible to understand this principle for me.

In the USA, Kinsler is a fairly well known supplier of racing engine fuel injection systems, parts, supplies, refurbishment. Their catalog at the below URL shows a schematic of a plumbing configuration for a (vintage-like) Lucas mechanical injection system (timed, not constant-flow). Your picture's #3 tank maybe equivalent to the "Vapor Separator Tank" in the diagram on p.228. It's purpose is to provide a bubble (vapor)-free supply of fuel to the high pressure pump(s) in the FI system.

https://kinsler.com/Kinsler-Handbook/HTML/228/


There may be plumbing schematics for other types of FI systems in other sections of the catalog, but Lucas systems are the only ones I am familiar with.

[eugen]

Great, thanks, that drawing on page 228 really looks a lot like my setup, with all the fuel lines and check valves. The small tank is either the vapor separator or the catch tank in the picture - although it has 3 fittings on top like the vapor separator I am more inclined to think it is the catch tank as it is sitting between the 2 main tanks.

Eugen

[J Leonard]

Original Lucus.

[Lee Johnson]

Original Lucus.

This is good old stuff! Thanks for scanning & posting it, James.

As shown in the title/note @ bottom right of the sheet this schematic applied to several variations of the Cozzie 4 cylinder BD-series motors. The Kinsler schematic I referred to earlier in the thread has some slight variations to this Cosworth schematic. One notable one is their use of their own 3 port check/combiner valve ,instead of the "N.R.V. {Non-Return Valve} on outlet" that Cosworth used in their crankshaft belt-driven high pressure fuel pump.

In Eugen's photo: the #3 tank does look like a "de-aerator tank" mentioned in the Cosworth schematic. With the long-bolt thru the center it might also have a Lucas/CAV fuel filter cartridge built into it. And, I think Darryl is correct that the (unlabeled) brass hex item on the top of the engine block is the "relief valve" shown near the metering unit on the Cosworth schematic.

All of these details may be extraneous to Eugen's actual car if it's got Weber carbs instead of FI.

Lee

[J Leonard]

O.P. said quad carb. Four Weber or 4 barrel?

[eugen]

O.P. said quad carb. Four Weber or 4 barrel?

A Holley carb is installed.

[eugen]

Thanks for all your helpful information! Yesterday I started the engine and had it running for quite some time and switched of the electrical pump after start up. The fuel pressure gauge showed a slight drop but the setup should run without the electrical pump. Good to know!

Eugen