1963 Chevrolet Corvette Convertible - Pushing The Limits

Next, Ken next needed a 3-inch aluminum elbow for connecting the compressor discharge to the F.I. plenum inlet. Because of limited space, Ken needed a short radius that would require mandrel-bending equipment. He found that most shops that do this type of work are limited to smaller-diameter tubing so, after several months of searching, he was referred to Josh Deeds at Innovative Turbo Systems in Simi Valley, CA. Josh was able to mandrel-bend a 90-degree elbow using .065 aluminum tubing within a few days.

With the major components in place, it was time resolve the vacuum system problems related to boost in the intake system. Four circuits that relied on vacuum were modified with check valves to prevent internal or external problems from boost pressure. They include the crankcase vent at the F.I. plenum, the power-brake booster, the distributor vacuum advance, and the fuel bowl vent into the F.I. plenum. Each line was fitted with a check valve from Smart Products, Inc. in San Jose, CA.

The Rochester F.I. idle circuit requires air plumbed from the air meter to four nozzle blocks (that hold the nozzles in place) at each corner of the plenum. Because the air meter was moved some distance from the lines used for this purpose, a small K&N air filter, PN 62-1360, was used to filter the air at idle speeds. The 3/4-inch opening at the bottom of the air meter was capped with a rubber cover.

The amount of fuel sent to each nozzle is determined by a vacuum control signal generated by "a highly efficient annular venturi between the air-meter body and a diffuser cone" in the air-meter assembly (Corvette Shop Manual, pgs. 6M-34). Ken designed and fabricated a new line using 1/4-inch steel tubing. On the air-meter end, a 1/4-inch "O" ring is used to seal the line, and a 1/4-inch compression nut and 90-degree fitting are used at the fuel meter end. If this vacuum line has the smallest leak, the main fuel-control diaphragm will not function properly and drivability will be erratic. Another 1/2-inch line runs between fuel-meter main diaphragm housing and the air-meter adapter to vent gas fumes. This piece was fabricated from 1/2-inch aluminum tubing and connected to the original tubing.

The Vortech supercharger uses engine oil to lubricate the gears that turn the impeller. On current small-block Chevy applications, Vortech recommends removing a 1/4-inch plug in the block located above the oil filter for the best source of filtered oil. Ken found that his '65 327 block was manufactured with a welch plug that would be difficult to remove, let alone tapping the block with a 1/4-inch NPT thread. He resolved this problem by inserting a 1/8-inch Tee in the line that is used for the oil-pressure gauge in the dash cluster. The fit is very close to other components, but it made a very clean installation. A return oil line is plumbed from the bottom of the supercharger gear case to the oil pan. Ken attempted to find an aftermarket oil pan to avoid cutting a hole in the original part, but found that current S.B.C. aftermarket pans are not designed for this vehicle. He finally gave in and cut a hole in the pan and welded a 1/4-inch NPT fitting in the left-front side. This was the only original part on the Vette that Ken had to modify in anyway.

With the induction system complete, Ken turned his attention to driving the supercharger. Ken used a 1/2-inch Gates V-belt, PN 9555, that is 55 7/8-inch long to drive the blower pulley refered to in step 3. To keep the belt tight, he used an idler pulley (arrow) and eccentric as recommended by Frank Mirate at Burbank Auto Parts. This idler runs on the flat side of the V-belt and was originally used on mid-'80s Chrysler products. The upper radiator hose had to be relocated because the V-belt driving the compressor was in the way. This was accomplished by using an aftermarket thermostat housing outlet and relocating the water inlet on the radiator. After an hour or so of searching, Ken found a molded upper radiator hose that could be cut to fit exactly.

Two vent lines remained to be fabricated. The first involved slightly bending a piece of 1-inch (outside diameter) tubing to connect the air-meter adapter to the crankcase vent, which is next to the distributor at the rear of the block. The second item was a 1/4-inch line from the exhaust manifold that provides heated air to the automatic choke.

Once all of the necessary brackets, braces, tubes, etc. were fabricated and the entire system assembled, Ken disassembled all of parts to send them to a plating shop. In the end, 50 pieces had been custom-made for this project, and Ken had scrapped 25 more pieces in the process of getting everything right!