When I was building the boat, I wanted to make the boat as retro as possible, while also putting some decent modern technology in to it. I looked at the Kinsler and Hilborn EFI setups and they are lovely, but I wanted to see if I could package it a little tighter and hide the injectors between the stacks.
I spent a lot of time searching until eventually I found a hilborn manifold that I thought I might just be able to squeeze some EFI injectors in to.
This the manifold in its original installation :
And as I got it , looking in generally good order:
There were 2 main challenges:
- To run an EFI system, I wanted at least some MAP (pressure) feedback to the ECU. At wider openings, vacuum collapsed quite rapidly on ITB setups, but for idle & off idle, I wanted a vacuum signal
- Could I find some injectors that fit
Vacuum “Plenum”
I decided that the holes already in the manifold for the fuel meter would make good mounting points for the plenum:
And machined up a block of aluminium to fit:
And I then made up a copper pipe & union running from each intake tract to the plenum:
This was the Mk1 version, since then I have put better unions on the manifold end. Overall, it works. I never expected to get much vacuum signal for the EFI, but I get some and it helps give me a nice smooth idle:
Injectors & Fuel Rails
I decided to get a set of Bosch EV6 “Pico” injectors from Summit, since I thought these stood the best chance of fitting https://www.summitracing.com/parts/fms-m-9593-lu47
After removing all the mechanical injector equipment and then carefully reaming out the mechanical injector mounts, I can “just” about squeeze a full set of EV6 injectors in, inbetween the banks
With the fuel rails mounted on top. It is a tight setup though, trying to squeeze injectors, fuel rails, TPS sender & fuel regulator in. But it all fits and it all works:
Matt Yorke 