Triple Mikuni Fuel Line Set-up

[fixitman]

Another arrangement to consider is shown in the attached photos. The premise for my resto/mod was "how would the factory upgrade an early 260Z", if they were to offer a moderately higher performance street model. Keeping that thought in mind, the carb system includes a factory NOS electric fuel pump with filter, mechanical fuel pump, custom fabricated fuel rail and balance tube.

The fuel rail utilizes the original brackets, modified as required, and stainless steel tubing. The rail includes lines for fuel supply and return, vacuum for the distributor vacuum advance and vapor canister, and canister purge. The return line contains the flow restrictor from the original fuel rail.

If you look carefully under the carbs in photo ending in 007, you'll see two heat shields. The one directly under the intake manifold is either from a 240 or 260Z. The other shield came with the Mikuni kit. The shields overlap and are bolted together.

The rubber sleeve fuel clamps for the SS braided hose are an British car item.

Hope this helps.

FixItMan

Edited March 27, 2011 by fixitman

[Travel'n Man]

David-

Thanks for sharing your set up - looks great. I have noticed on other posts here and Hybridz that states that we should not have a vacuum from the distributor set up - (I was planning on leaving my unattached and working on my timing setting:

Run more initial timing

• 12-14 degree advance @ 1000rpm
  
• 36 degree total by 3000 rpm
  

What are your thoughts and how is your timing curve?

[fixitman]

David-

Thanks for sharing your set up - looks great. I have noticed on other posts here and Hybridz that states that we should not have a vacuum from the distributor set up - (I was planning on leaving my unattached and working on my timing setting:

Run more initial timing

• 12-14 degree advance @ 1000rpm
  
• 36 degree total by 3000 rpm
  

What are your thoughts and how is your timing curve?

If I remember correctly, the tech advanced the timing a little but I don't know the particulars.

Dave

[ChrisZ]

Mitchell, sorry for my late reply, as for fuel lines, i run the stock lines to the mechanical pump, from there it run to the JDM fuel rail and from the rail i use 8 millimeter hoses to the carbs, works fine.

The heat shield, is a thin pice of aluminium sheet, i bend in a shape very close to the one in the link you posted, simple and work fine, no heat issues.

Chris

[Travel'n Man]

Chris -

Thanks for the info on the sizing - your set up looks great - I'm really fired up about this project!

A few questions for you please:

• Are you running an vacuum on your dist advance?
  
• Are you deadheading your fuel line or using a return (I believe the JDM deadheads).
  
• Do you have another JDM fuel rails -those things are tough to find!!!''
  
• Any recommendations on my set up?
  

Thanks for you assist!

[RIP260Z]

Mitchell,

I think I sold Chris the fuel rail... anyway, it is the same as what I have.

Mine pictured is an after-market produced one, which I saw sold on Yahoo Japan. I think this is a copy of what was available in the S30 Sports option list, e.g for Mikuni, back in the 1970's. As you see I am running a return line. The return line is smaller than what supplies the carbs. I also put a reducer inside the pipe, the gives something the fuel can pressurize against (rather than running the same dia. fuel pipe) but still let fuel return. I have a small cylinder of brass pushed in, with a 1mm hole drilled through it. I am trying to replicate the system found on the end of the OEM fuel rail.

Hope that helps

Ian

[ChrisZ]

Wot are you saying Ian, is it not a original Nissan fuel rail, but some kind of knock off !!.... who cares:classic:.

Mitchelle.

No vacuum, i'm planning on putting on a balance bar on, hence the brass plugs on the bungs, the bungs have been milled and tapped and the balance bar will also be tapped for the PCV.

Deadheading as Ian say

I do not have another but now you know where to look.

I will recommend you to use the stock fuel rail, if the connections on your carbies is T connections, i have seen it be done many times before so it must work, you should focus on getting a solid linkage, unless it is solid already.

Chris

[Travel'n Man]

Great info guys! I'm sure this info will assist all that are piecing this puzzle together as well as myself. Once I finalize my set up I will post the details. I do believe a return line is the best for the performance as well as a heat shield of some sort.

There must not be a lot of Mikuni owners out there since we have only had a few responses back on this subject.

[ChrisZ]

Can't say, mine are Dell-ortos :classic:

[Z-point]

My old set-up

[gnosez]

Once I finish up this field project from hell, I'll post pictures from my street 240 w/44's and our 240 race car with the BSR taper bored 44 to 50mm Solexes. Gotta go back to work...but the race car will be in Savannah for ZCON 2011.

[spitz17]

My current set up on a 3.0L Rebello Stroker

Edited July 14, 2011 by spitz17