21 replies to this topic

[makka]

if you need to you can always run the surge/header tank in the engine bay

[ls2lxhatch]

[ls2lxhatch]

Glen at Browns Radiator Service is responsible for the fabrication, I am responsible for the design.

The dimensions are similar to the Brown Davis tank but 50 mm shorter, different angles at the front, different mounts and the flat spare wheel area. The tank is made from 3 mm sheet edge welded which is a totally different construction method to the Brown Davis tank. ( I think the Brown Davis construction method is better but not practical if you have to send sheet out for bending. )

The surge tank is 4.5 litres, the lift pump is a Goss GE034 and the EFI pump is a Bosch 044. The fuel filters are Aeromotive 100 micron for the lift and 10 micron for the EFI. The fuel level sender is VDO.

At each stage of fabrication, I have been taking the tank home to confirm measurements and clearances. I took this picture when I was checking the location of the pump, filter brackets, hose fittings and vents. The tank is back at Browns to be completed to the stage where it is ready for the top. Once that is done I will pickup the tank so I can test the surge tank return flow and internal construction. Then back to Browns to get the top tacked on, then back home to mark the mounting bracket positions then back to Browns to finish the tank. It has only taken three months so far and now my hatch is away for another three weeks getting some preliminary trim work done.

[ls2lxhatch]

My system is setup to run a return line. LS1LX is running a deadhead system on an LS2.

Litre8 and A9X have a surge tank in the engine bay.

It would be worth checking if it is legal in your state to fit a surge tank in the engine bay. I am not particularly comfortable with the idea myself but it does have its benefits.

A forum member had a surge tank made that bolts to the boot floor with all the fuel fittings in the bottom of the tank with different length tubes. This allows you to have a surge tank in the boot with all the fuel lines external.

I plan to make my prototype fuel lines from 3/8" aluminium tube mounted using these clamps.. The lines will run down the drivers side on the outside of the chassis rail, under the guard to a bulkhead fitting in the splash panel. Up to the fuel rails then back to the regulator will be fitted to the splash panel. I plan attach the clamps using nutserts and mount a stone shield to the T-clamps where required. Once I have finished the fuel lines in aluminium tube I will remake them in stainless.

I expect to complete the prototype fuel lines in about five weeks.

Edited by ls2lxhatch, 10 March 2009 - 11:59 AM.

[A9X]

Andy that looks good mate.

We are about to bolt quad webers to the old girl and part of the job is to remove and replace both front tanks, fuel and oil catch. Have yet to finalise the actual plans for where the replacement is going.

Appreciate the links to the pipe clamps too, good stuff.

[ls2lxhatch]

I look forward to hearing the quad webbers. Why are you replacing the surge tank?

[ls2lxhatch]

I bought a Brown Davis tank when I was planning to run a SBC with a carby. I considered modifying the Brown Davis tank for EFI but decided it would be cheaper to sell the Brown Davis and start from scratch.

The fuel line guards will probably be made from 1 mm aluminium or mild steel sheet, possibly sprayed with proof coat.

The original fuel line runs on the inside of the drivers side chassis rail close to the exhaust and gearbox and then within an inch or two of the extractors. My fuel lines will follow the path of the original fuel lines from the tank up to the point where they cross over to the inside of the drivers chassis rail. At that point I will continue to run on the outside of the chassis rail to minimise exposure to heat from the exhaust, gearbox and extractors.

One problem with the return fuel system is that the fuel rails heat the surplus fuel passing through on its way back to the tank. Depending on the amount of fuel in the tank and the fuel system design it does not take long for the temperature in the fuel tank to rise considerably. Running the lines away from heat sources and in airflow will reduce the problem.

I also plan to mount an aluminium heat sink in the return line. The instructions show the heat sink mounted before the fuel rail but I think it will be more effective at keeping the tank cool fitted after the fuel rail. If fuel temperature is still a problem then I was considering fitting heat sinks to the bottom of the drop tank.

Edited by ls2lxhatch, 11 March 2009 - 01:34 AM.

[A9X]

Andy i've never been happy with the fuel pump/filter setup , so with the change to webers i'm taking the opportunity to revamp fuel delivery from tank to carb.

Had many a comment about the surge tank in it's location and with the added fire risk associated with racing and front end impact, i'll look to a change , maybe, as with the whole system.

[Rockoz]

ls2lxhatch

I can see what you are trying to do putting the heat sink in the return line, but the intended purpose of these heat sinks is to cool the fuel as much as possible before the motor.

Cooler fuel is denser, so more bang available.

This is why some use ice tanks.

The pump actually heats the fuel during the pumping process. Its just physics.

A cooler in the return line isnt a bad idea, but one on the delivery side may be more beneficial.

[makka]

hey Greg, how deep does that sit?

[ls2lxhatch]

I can see what you are trying to do putting the heat sink in the return line, but the intended purpose of these heat sinks is to cool the fuel as much as possible before the motor.

The fuel tank is the bigest heatsink you have.

If you are building a car for the strip, then I agree that the optimal location for the heat sink is between the fuel pump and the fuel rails. I think this is more important for a carby than it is for EFI. I think the ECU is able to compensate for the higher fuel temperature by injecting a larger volume.

My car is intended as a daily driver so it will be stuck in traffic regularly. These are the issues I have been considering.

1. The heat sink will be most effective where the difference between air temperature and fuel temperature is the greatest.
2. The lift and EFI fuel pumps are cooled by the fuel, hot fuel can cause the fuel pumps to fail prematurely.
3. The temperature increase caused by the fuel pumps is trivial compared to the temperature increase caused by the fuel rails in a return line system at idle or low speeds.
4. I have seen fuel tanks on street cars that are too hot to touch after a long trip when the tank gets down below 1/4 full.

I was tempted to fit two heat sinks however space and cost is an issue. When the car is driven in traffic for half an hour or more I believe the heat sink in the return line will result in lower fuel temperatures overall and lower fuel temperatures in the fuel pumps. If there is any power loss due to higher fuel temperature at the fuel rails I doubt I will notice on the street.

Edited by ls2lxhatch, 13 March 2009 - 02:23 PM.