Triple Mikuni Fuel Line Set-up

[Travel'n Man]

As Dave Rebello would say "Bitch'n!!"

[Travel'n Man]

Update -

Adding a 100 micron Holley Fuel Filter 162-551 between the tank and the fuel pump. I did have an overflow challenge on one of my carbs due to the needle valve sticking open. Naturally it was the carb over the header and the raw fuel was pouring right on top of the header - then I had the brainstorm of cupping my hand to catch the fuel - well, that was not a very good idea either if the header would have caught fire my hand full of fuel would have been right there with it. Looks like I'm going to be in the market for a fire extingisher as well.............just in case.

Anyway - there is a project for next winter - pull the tank - clean & seal!

[Bonzi Lon]

A fire extinguisher is mounted behind the driver's seat of my 240Z. Even though it is a single purpose tool, it is still cheap insurance.

Bonzi Lon

[Travel'n Man]

Agreed!

[steve91tt]

Wow, glad both you and your Z are alright. I'm ordering an extinguisher today.

[LeonV]

A fire extinguisher is mounted behind the driver's seat of my 240Z. Even though it is a single purpose tool, it is still cheap insurance.

Bonzi Lon

I have one in every car, with the Z's being behind the passenger seat for easier access while sitting in the driver's seat.

[Mike W]

A couple of questions for D240zx2 (frank I believe).

So I have a similar setup on my 260Z with triple Webers and have been wanting to change out the rubber lines I have now with a braided AN setup with a fuel distribution block. Your installation is the closest I have seen to what I am looking for (and yours looks great by the way). I have a few questions that hopefully you can help me with:

1. Where did you get the bracket to mount the fuel block to the bolts on your intake manifold? Was this custom made or were you able to purchase a bracket to start with even though there might have been modifications required?

2. You indicated that you used only an electric pump by the fuel tank. Did you need to install this or was it already there? Also did you need to do anything specific to get the pump to run all of the time? I know that on my 260, the electric pump does not start running until the engine reaches 600 rpm so I also have a mechanical pump in my system as well. If I went with a setup similar to yours I would need to find a way for the pump to run as soon as the key was turned on but also find a way to disable it in the case of an accident (ie low oil pressure or something similar). I assume that you completely removed your mechanical pump and just used a block off plate instead.

3. How did you make the transition from the hard line coming from your tank / pump to the AN fittings? Did you use the original hardline installed on the car or did you run a new one? How did you connect the two together?

Thanks in advance for your help. Your system looks awesome and so I appreciate your help in getting mine to look similar.

Mike.

[conedodger]

Mitchell,

I'm wondering why not use the mechanical pump and why not use the return line. What were the reasons given? One would think that fuel starvation would be more of a problem than too much fuel. As long as you can maintain the small amount of fuel pressure needed for Weber/Mikuni/Solex/Dellorto carbs a return line should not be a problem.

[d240zx2]

Sorry for the LARGE delay in answering this publicly... I hope our PMs have answered your questions sufficiently....??

Frank

[Travel'n Man]

Mitchell,

I'm wondering why not use the mechanical pump and why not use the return line. What were the reasons given? One would think that fuel starvation would be more of a problem than too much fuel. As long as you can maintain the small amount of fuel pressure needed for Weber/Mikuni/Solex/Dellorto carbs a return line should not be a problem.

Rob -

I spoke with several folks from racing to engine building to carb work and everybody told me that nobody ran a return fuel line and all were in agreement of 3 PSI - From my research it is better to push the fuel than to pull it with a better fuel flow and more consistant flow. I can push my car as far as I want and there is no stutter - hesitation - stalling of any kind. I was very concerned with vapor locks - hot fuel - low pressure......................so far my set up is dead on. I did not try to overcarb my engine or under power it with my engine modifications. I feel that I have gotten my power band vs hp vs fuel flow about dead on. Planning on hitting the dyno next month - it will be great to see what kind of numbers I am actually putting down.

Edited August 16, 2011 by Travel'n Man

[Travel'n Man]

Dyno Update

• Rear Wheel Horsepower = 154.11
  
• Torque = 172.21
  

Engine / Mikuni details can be seen in my garage.

Edited September 11, 2011 by Travel'n Man