As previously stated, I really didn't want a carburettor perched on my Ford V8 as I didn't want the hassle of babysitting it. But I did want to retain the traditional look whilst taking advantage, and having the benefits, of a hi-tech engine management system. So with those criteria set-in-stone, I opted for the MSD Atomic EFI unit. This is a square bore carb' lookalike unit which sits where the 'traditional' carb' should sit, and it contains all the sensors and gubbins to provide total electronic fuel management.
The package comes with everything you need: i.e. the main square-bore bolt-on EFI unit; fuel pump; fuel filters; high-pressure fuel pipe, and all the fixings. It also has a very nice looking Power Controller unit "black box" (which is red) and a plug-in hand-held controller which allows you to alter and tweak things without a laptop. I also don't need to relay this as it's all taken care of internally.
The 'stock' place for the fuel pump and filters on a GD MkIV Euro is on a very nice backing plate sitting just behind the diff'. However, I've decided not to fit the fuel pump and filters here; because, as I have compression clamps on a rubber hose fuel line, having something with a pressure of between 30-70 psi sitting directly above very two hot exhausts is not my idea of health & safety... So I'll be mounting the pump and filters in a tin box in the boot with a vent to the outside.
Removed the GD positioned copper fuel-pipe and run the MSD hi-pressure "soft" pipe down the ladder frame to the front of the car. Note: It is not recommended [by MSD] to run the pump with a "hard" fuel line. Something to do with how it pulses to provide the unit with just what it needs. Also, this type of fuel system is returnless (or not if you want it to not be.)
Also, I didn't want to hide the Power Controller away anywhere as it looks good and beefy, so I put it on the firewall next to the fuse boxes.
Requirement: I needed an accelerator pedal stop... As I’m ‘driving-by-wire’ a pedal stop is important as it takes all the strain off the throttle linkage if-and-when your foot goes to the floor. In the case of a carb’ or as in my case with the MSD square-bore EFI, putting your foot to the floor will cause strain on the linkage end. This is because the pedal box is deeper than the necessary amount of pedal travel.
Production: My solution, and there are many different intuitive designs out there, was to make an adjustable accelerator pedal-stop out of an M10 bolt, a couple of nuts, a large penny washer, and a piece of steel plate… The cable is a bicycle brake cable and the outer is from ‘Jag’ race bikes spares, and it’s yellow to match the HT leads and heater cable outer.
Specifically, I made a small backplate, welded an M10 bolt to it and drilled for a bulkhead M6 securing bolt (and I glued the plate to the bulkhead too). The long M10 bolt being the functioning and adjustable ‘stop’.
This is further secured with a locking nut. The pedal stop backplate sits directly behind the pedal high’ish up the lower arm so as to be out of the way.
Adjustment: I needed to facilitate a throttle cable travel of 5 cm… But! The throttle pedal armature can only provide for a throw of 3 cm. This is because the length of the accelerator pedal arm (above the fulcrum point) is shorter than that of the below armature (this being the distance from the fulcrum point to the pedal.) So, with this differential to deal with, measuring the pedal travel to create a 5 cm cable travel worked out to be, I needed it to travel 7 cm. Not concerned with this as it means the car will be less twitchy.
Nice view of the Power Controller and MSD Air Cleaner
Lastly, the accelerator pedal will be ~2 cm lower (further forward) than the clutch and brake pedals. This is how it is on regular cars so that’s good enough for me…
Positioning: Trial fitted the fuel tank in the boot, and I decided to reposition the two retaining straps to the outer edges of the raised centre part of the floor. A total move [inwards] of about 5 cm for each strap... When I measured up I had a concern with the positioning and proximity of the securing bolts as they would have been virtually touching the top of the silencers. There was ~0.5 cm clearance for the nyloc nut and load-spreading washer, which really wasn’t enough for my liking. Moreover, I was not happy with the nyloc being so close to the heat source.
Insulation: I used 25 mm x 10 mm foam strips for the bottom and 25 mm x 6 mm strips on the back of the tank. I also stuck some 2 mm rubber sheeting on the underside of the straps to insulate those from the tank too.
Fitting the Retaining Straps: Bending and fitting the steel retaining straps was interesting, and I became aware very quickly about “bend radius” and how the straps needed to follow the angles of the tank; in my humble opinion, the strap shape at the edges had to be a proper fit otherwise the majority of the holding force would have been on the contact point... Not good.
Made an aluminium strap template and marked up where the bends were to be (allowing for the radius,) then I bent the lower bend and got that to fit properly with some judicious use of a club hammer. Then I re-verified the upper bend location and bent and bashed for that with the club hammer.
Bending was achieved by clamping the steel strap in a homemade jig. Essentially the jig was a couple of pieces of angle iron with bolts at each end. Bend procedure was: heated up the area to be bent, then, by further clamping the piece between two additional metal plates to keep it as flat as possible [when bending,] made the bend. Then I finished off with the club hammer.
Fitting was with socket-head bolts and nylocs on the underside - not forgetting the large load-spreading washers, on the topside.
So, the tank is fully insulated from any contact with metal or GRP and is firmly and snugly cushioned and positioned. And there will be nothing protruding into the boot area or in close proximity to the silencers... Happy with this.