Parts I need for 240z Carb upgrade to Triple Weber 45DCOE

[tamo3]

I plan to upgrade '72 240z SU carb to tripple Weber 45 DCOE over the July 4th weekend.

 

Here is my research data:

240z SU carb car has narrower diameter fuel line compare with 280z fuel inject car.

240z fuel related line diameter is following(correct me if it's wrong)

• 5/16″ OD (might be 8mm) supply
  
• 3/16″ OD return
  
• 1/4″ OD vent hard line (the one on the driver’s side)
  

 

 

So far what I got:

- Weber 45 DCOE tripple Carb with Canon intake

- Carter GP4070 Fuel pump

- Summit Racing SUM-G1438 Oil Pressure Safety switch

 

And plan to get

• Summit Racing SUM-800115 Pressure gauge
  
• Mr. Gasket 2975 - Mr. Gasket Fuel Pressure Gauge Adapters
  
• Holley 12-804 Fuel Pressure Regulator
  
• Mechanical Fuel Pump Block off Plate to head
  
• LOK-TC-1000U Lokar Throttle Cables
  
• Some fuel filter
  
• Fuel pump rely
  
• Fuel line
  
  • from factory hard line to Carb
    
  • from carb to fuel pressure regulator
    
  • from fuel pressure regulator to factory return line
    

  [*]Some fuel filter

  [*]some an fitting

 

 

Question is:

What fuel filter(s) do I need?

I read some instruction I need 100micron fuel filter between fuel tank and fuel pump, 40micorn fuel filter between fuel pump to carb.

 

Do I need rely for fuel pump?

Holly FPR manual mentioned relay, but not in carter.

 

What size of fuel line do I need?

Holly FPR state 3/8" fuel line, but not in carter. My understanding is factory fuel line is 5/16". I think a lots of 240z owner install Weber/Mikuni 40, 45 carb. I wonder everyone replace entire fuel line.

 

Do I miss something?

I would like to prepare all the parts I need within June. I should order now. If you think i miss something I need, let me know!

 

Thanks for looking.

tamo3

Edited June 18, 2012 by tamo3

[BluDestiny]

I was running 2 cheap glass filters that you buy at autozone. One near the tank, and another right before the fuel rail. I don't recommend them though since both of mine leaked at one point or another and I had to change them.

 

Each fuel pump is wired differently, so wire it per the instructions that came with it. I was running a cheap pepboys low pressure carb fuel pump, with a cheap regulator set to 4psi.

 

You will be fine with your return line. I didn't modify anything in my fuel system, all the cheap stuff that I listed was already on it when I got the car. It worked for my Su's for a couple years and worked fine for my webers.

 

My honest opinion: You're overthinking it. Which is good and bad.

 

When I did it, I bought a complete set of carbs manifold to air filters for $600 and basically spent 2 hours removing my SU's and cast ex mani, then replacing it with a set of headers and my triple webers. I didn't change anything else. It ran, but not really that well, turned out the carbs were all jetted differently and 2 of them had holes in the floats. After I got them rebuilt it ran decent.

 

My advice, put in the fuel pump and filter and sort your fuel system out now with your SU's that you know are good, so you don't go blaming the carbs.

 

You look like you have/know everything that need.

[tamo3]

Thanks BluDestiny for your advice.

 

I did so much try & error for the brake parts, I want to make it right especially fuel area which is flammable and become cautious.

I will try new fuel pump with SU at first.

 

Does your car 240z or 280z?

I thought 240z and 280z has different size of fuel line. Since 280z is fuel injection, that has wider diameter fuel line. 240z has 5/16"(8mm) diameter fuel line that could be the bottle neck for fuel delivery. That's I'm worried about.

 

I'm still look for advice for fuel filter.

 

Thanks,

tamo3

 

I was running 2 cheap glass filters that you buy at autozone. One near the tank, and another right before the fuel rail. I don't recommend them though since both of mine leaked at one point or another and I had to change them.

 

Each fuel pump is wired differently, so wire it per the instructions that came with it. I was running a cheap pepboys low pressure carb fuel pump, with a cheap regulator set to 4psi.

 

You will be fine with your return line. I didn't modify anything in my fuel system, all the cheap stuff that I listed was already on it when I got the car. It worked for my Su's for a couple years and worked fine for my webers.

 

My honest opinion: You're overthinking it. Which is good and bad.

 

When I did it, I bought a complete set of carbs manifold to air filters for $600 and basically spent 2 hours removing my SU's and cast ex mani, then replacing it with a set of headers and my triple webers. I didn't change anything else. It ran, but not really that well, turned out the carbs were all jetted differently and 2 of them had holes in the floats. After I got them rebuilt it ran decent.

 

My advice, put in the fuel pump and filter and sort your fuel system out now with your SU's that you know are good, so you don't go blaming the carbs.

 

You look like you have/know everything that need.