The supercharger housing was machined from a solid billet of 6061 T6 aluminum, the intake manifold is removable I just forgot to take it off. This was one of the fun parts to machine, I started with a rectangular block faced to size, and I then located and bored the two rotor holes. To machine the webs in the side of the case a shaft was passed through each bore and locked to the case by pins located and drilled where the intake and exhaust ports of the supercharger were to be placed. The shaft and case were then set up between the centers of the rotary table and tailstock on the mill; it was then possible to mill the compound recessed areas with a ball nose endmill. The shafts were removed and the intake and exhaust ports were milled, to ensure the rotors would be located in the right spot and be running true in the bores, the front and rear bearing plates are aligned with ground pins on the two outermost holes of the bolt pattern.
The rotors are made of aluminum with drill rod shafts pressed in the ends; both rotors were turned between centers in the lathe to ensure they ran true. The sliding vane slots were milled with a woodruff cutter between centers of the rotary table and tailstock on the milling machine, drive pins to lock the gears on the shafts were drilled and reamed at this time.
The sliding vanes are made of aluminum, they required a bevel to meet with the case bore on the leading edge, this was done and a thin slot was made down the length of each vane with a slitting saw. I pressed and bonded a strip of Teflon in this slot and milled the material true with the vane.
The material I called Teflon may not be exactly what it is, this was used in a second attempt after I had originally used Corrian to make the entire vane out of, and it failed miserably. I was trying to locate some of the carbon graphite material used in old semi-truck air starter motors, with no luck a friend gave me some used rings out of a large oil field compressor motor, they are about 12 inches in diameter and very thick. The material is very heat resistant and seems to look and feel a lot like Teflon, it is black in color and machines nice, since I needed long flat pieces to press into the aluminum vanes I heated the rings of material up and squeezed them flat with a vice, when they cooled down they retained the flat shape. I have run the motor many times with these vanes and have not had any trouble yet.
EXHAUST HEADERS AND MANDREL BENDER
The ignition system for my v8 uses two distributors and two separate electronic control units. The use of two distributors serves no real purpose other than my next V8 based on this prototype will have two spark plugs per cylinder.
The distributors are both driven at a 1 to 1 ratio off the rear of the camshaft through small steel bevel gears, one spins clockwise the other counter-clockwise, this may seem like a nightmare to get the timing set right on both distributors but it is actually very simple. I will go into more detail on setting the ignition timing when I start the reassembly pages.
The distributor bodies were machined from aluminum, a drill rod shaft rides in small ball bearings and spins an aluminum disc with four tiny magnets pressed into holes in the periphery spaced at 90 degree intervals. The rotating magnets trigger a Hall Effect sensor and tell the electronic control system when to fire the plugs.
The distributor rotor and cap were made from Delron, the cap's terminals were made from built-up pieces of Delron and brass contacts, the rotor has a small brass strip that makes contact with the center coil terminal of the cap. Plug wires are inserted into the terminals and a 0-80 cap screw in the side of each terminal holds them in place.
The ignition systems used are made by CH Electronics; they are called a Syncro Spark system. These are mostly used in RC planes; I liked them because they are so tiny. They originally came in a very small aluminum box about 1.5 inches cubed. I removed the coils and circuit boards from these boxes and mounted each coil in it's own housing made from Delron, the electronic circuit boards are mounted into the small finned aluminum cases below on the rear motor mount. The electronic controls automatically retard the ignition timing for starting and control ignition advance based on RPM.
I have no affiliation with CH electronics and I do not know if they will sell these ignitions for this purpose.
The exhaust header tubes were made from 0.625 inch type 1010 seamless hydraulic tubing, this material was chosen because it has good bending qualities. The header flanges were made from ground gage stock.
I messed around for days trying to get nice bends in the tubing with homemade bending dies of several different styles; they all turned out looking like they had been gnawed on by packs of wild dogs. I needed a very tight radius bend without any deformation in the diameter of the tubing. I decided to build a mandrel type tubing bender.
I will try to explain the best I can how it works, first a length of tubing is inserted into the die former (look at picture directly below these words), the tubing is then clamped down in the split block with the four small cap screws, so now we have a length of tubing sticking straight out of the bender die (the part with the bearings and ball handle below). The die and tube are then slid over the brass bullet shaped slug and the bearing pivot shaft is inserted. The ball handle will now be sticking out strait forward of the whole device. The tubing can now be bent by pushing the handle back toward the rear of the bender. I had underestimated the force required to do this and ended up clamping the whole assembly down and using a three foot length of pipe slid over the handle, the inside of the tube needs lots of lubricant also.
The bends in the tubing turned out great.
The bent pieces were then cut to finished size and TIG welded to the header flanges with the welding done on the head side of the flange. The picture of the headers above still has the gaskets stuck to the flange face, that's why the flange looks odd.