Hello,

I finally bought a very nice (pristine interior and minor rust) 77 280Z. Being that I am a carburetor guy (if for no other real reason), I am converting the FI to Carbs. So, I have been looking for the non-emissions early SU-Hitachi carb. However, since I also own a 1964 Volvo 122, I have a reasonable share of HS6 and HIF SU carbs. And this got me thinking about whether I could fit a set of HS6 to the Datsun…

Has anyone done this before? This may be uncharted territory, but I’m quite comfortable there. If anything, this may just be a fan project.

Thank you,

Marco

Marco,

I would check with Bruce at ZTherapy.

My guess is they won't work (at least easily).

I converted my 76 FI with a pair of 72 SU's and they work great.

Sorry I can't give you a definitive answer. I'm sure others will chime in.

Dave Ruiz

Hello Marco,

I just got through doing the same conversion with my 78 280Z , (4) screw carbs and I got with Bruce at ZTherapy "Great people to deal with". I agree with the advice of Powderkeg. I know the drill very well since I just did it about 3 months ago, if you need a plan of how to make it work

Mark

Thank you, Dave... I will talk to Bruce later on.

Mark, thank you for helping. Question, what did you use for fuel pump? I've been thinking about the Holley pump MSA sells as the head has no provision for mechanical pump. I really want to delete as much as possible from the stock FI, including all electrical components, relays and wiring. Did you do this as well?

Cheers,

Marco

My car never had FI, but I am using the Holley "red" electric pump on my SU equipped 240Z with no issues. (Other than it is noisy.)

I used the 83 Mazda RX-7 fuel pump carburetor model (O'reilly Auto Parts-" Bestest BE8016S") it is very quiet. I removed ECU wiring harness, leave the wiring where relays are at the right hand side you will have to leve the fuel pump relay, also you will have to run a new wire from the run side of the iginition swith to the fuel pump relay to power it for the run cycle. If you can get a hold of the 260Z intake manifold it has a little better flow than the 240Z, I use the 240Z manifold and it works for me. You will also have to pick up several brass fitings to make up fuel lines at the fuel pump as well as under the the hood 3/16" to 1/8" this is the fun part but it can be done. Also I would pick up a inline fuel filter to place right before the hardlines to the carbs, also you will need to pick up a 240Z fuel rail, also I removed all of the EGR stuff. It took me a little time to gather everything up but I am happy, I have simplified my life witht he carbs. I have nothing against EFI but the previous owner did some very bad things to my wiring harness. If you shoot me a private message I will send photos of my setup if you would like.

Edited November 16, 201014 yr by 78zcar_blue

I just replaced Su HD8 carbs on my L28 equiped 260Z. Here is a quick video of the last time it ran before removing them. I know they are different than the HS6 but still an SU carb and not hitachi style.

This is what is breathing under the hood now.....

Since the Hitachi SU that came on the 240z is basically a metric HS6, I don't see why not. As long as the linkage will hook up, that is.

I think the linkage would be the big hurdle. I suspect the HS6 will bolt up fairly easily to a Nissan manifold, and if you use .100 jets and SM needles you should be in the right ball park.

And help me out here..... are we still thinking that old Marco is still waiting for an answer to a question he asked November 16...... As slow as I am, even I get on with projects in under 5 months..... Just shuckin' ya all......