For the engine induction, I've been scratching my head trying to work out the best approach in regards to trumpet placement, size and design - considering the space I have to work within, as well as how I'd like the engine to behave.
I dummied up some alloy sheet to build a template for the engine valley-plate and the rails that will link the 4 throttle butterfly levers on each bank. With the ports being equally spaced and the levers all running in a singe plane, I can (relatively) simply design throttle rails to suit. Building the temporary valley-plate was wise as it allowed me to check the height and subsequent angle of the levers that connect the throttle rails on each bank to "bell crank" that sits in the middle of the valley.
These photos give you an idea.....
Seeing the bell crank is what the throttle cable (coming from the accelerator pedal) connects to - to open up the butterflies, it has to be "dead center" along the mid-line of the valley. I tried positioning it towards the rear to free up room at the front, but ended up at the "for/aft" mid-point anyway. Only this position gave me the optimum angle of pull on the throttle rails (as they travel their arc from closed to W.O.T.).
You will see some old trumpets sitting on the throttles just to give me an idea of the room i have (or don't have). I could go for much shorter trumpets right on top of the existing throttles. This means shorter inlet runners that sacrifice low-down torque - but i doubt this engine will suffer from a lack of torque! We will see how we go with this while i help draw it up on the CAD/CAM program.
Those blue-anodised trumpets give a false picture though, as they are for 50mm diameter throttles and mine are 55mm. The bigger throttle diameter makes a much bigger resultant trumpet - so really, i have less room than the photo indicates.....
This custom induction has also means a redesign of the dizzy and water coolant passages - as viewers will plainly see in the photo above.
I've chopped off an old 351C dizzy body right where it exits the block and gets tightened down by the locking tab. That "collar" you see on the chopped off shaft is actually the old bearing from the upper chopped-off section (that i pressed it out) that I had simply slid back onto the shaft. I have already pressed this bearing back into the dizzy housing stub you see here. But I had to open up the passage in the dizzy body to 0.750" (just under this size actually) for it to have an interference fit back in.
This new unit will very soon become my "Cylinder 1 reference signal" for the EFI control box. All "sequential fire" ECU's need to know when each cylinder hits TDC from a crank sensor, but to get the firing order, spark and injector timing right - it also needs to know when No.1 cylinder fires (and the rest flow from there).
You can see the hall-effect sensor sitting there about be positioned. This whole new unit will be a verty low profile and fit nicely under the coolant outlets. And speaking of which, those coolant outlets will both be redirected to the right of the pictures and combine into a single pipe in front of the heads - before flowing forward to the radiator in a conventional manner.
I'll add to this post as the induction gets further advanced.
Below is an "in progress" shot of the dash and gauge cluster. Well - it happens to show parts of this by pure fluke..... But the dash & gauges will be a separate post in itself.
