914/6 EFI project

I am slowly gathering parts to eventually fuel inject the 914. I've like all my cars to be on an Atkinson diet. No CARBS! The two options bouncing around in my head were either to use more TWM individual throttle bodies (ITBs), like my 911, or to buy a 3.2L Carrera intake manifold. The TWM option runs around $1400 and I would be able to reuse the manifolds, air cleaners, and linkage from the Webers. A used Carrera intake is $700+ for the intake, throttle body, fuel rails, and other small parts. A common plenum system is easier to tune at idle but the intake woosh sound from ITBs right behind your head is just intoxicating. Plus, ITBs just look more period correct.

However, this decision was made for me when a local set of cracked 3.2L Carrera intake manifolds became available for free. There had been a backfire in the intake and four out of six of the the inner mounting ears had broken off (carb cleaner plus reversed flywheel sensors = POW!) To repair them I cleaned up the castings, TIG'ed the ears back on, and then ran a large end mill across the flange to ensure they were flat. The trickiest part about welding was trying to get inside the end of the runner. The torch wouldn't fit very well and the electric field causes the arc to want to wander WAY up inside the tube. Sort of a joacobs ladder effect. It tried my patience but I eventually got it done.

The fuel rail and throttle body would be the next hurdles. Most people won't part out a complete intake but I posted on pelican and luckily found a throttle body for $125. One down, one to go. I couldn't find as good a deal on the fuel rails but I had already hatched a different plan. I really wanted to use black AN Aeroquip SOCKETLESS hose thoughout the build for both safety and a semi-factory appearance. The 911 already has all the bling braided stainless hose one could ever want so I wanted something lower key. The factory fuel rails would have odd metric flare fittings on them anyway and whle they can be cut off and AN fittings welded on I went a differnet route. Armed w/ my 'new' 1969 vintage Bridgeport Mill, I made my own. I ordered some aluminum extrusion and tooling and went to it.

The most expensive part was finding a MS 16142 port countour cutter to put the proper angles on the end for screw in AN6 o-ring fittings. I thought about making my own on the lathe, but the dimensions are critical with high pressure fuel and fire at stake. Plus, I eventually found one for ~$100 which was cheap enough not to bother w/ DIY.

The blue AN fitting is just one I had on hand. I'll order plain looking nickel plated ones for the final application. I've since bead blasted the fuel rails to match the intake manifold's sheen better.

I've sourced a few more bit and parts, but I'm waiting to find the time (ha!) to go further on the project. I'm almost 100% sold on using a Microsquirt ECU. Discrete, waterproof, and DIY fit right into the projects theme.