Sunday, March 23, 2008

Nostalgia Drag Bike? part II

Just to add a little more info on the blower I "won" on eBay. The gentleman I purchased the blower from tells me that it was on a Knucklehead drag bike named "The Gorilla" owned by Don Jones of California. I understand that there are pictures existing of the bike, but whether I will be able to obtain copies of them is still up in the air. That's about all the information I have so far.

As it turns out, when it arrived, I found some lettering stamped into the front bearing housing. S.CO.T. and under that the number 101. This is all stamped on a slightly raised "boss" that looks to have held a "serial number" type plate at one time. If there was indeed a plate there at one time, it would have covered these stamped letters. I am guessing that the 101 is a reference to the size of the blower.

The little that I know about S.Co.T. blowers is that they were a company that built supercharger kits for various engines in years gone by. I have seen them mounted on high end vintage style hot rods with Flathead Ford V-8s. The initials stand for "Supercharger Company of Turin"

Fabricated carb to blower manifold

One manifold (carb to blower) is obviously fabricated from steel, and I must say rather ingeniously at that. I doubt that I would have thought to make it out of sheet metal in a rectangular shape instead of struggling to get round tubing bent to fit.

The other manifold is cast aluminum, and though the center to center distance on the ports is in the ballpark for use on a set of dual carb Knuck heads, it likely was built by the supercharger manufacturer as a bolt on kit for a different application. The ports on this manifold are too small to match up with a Knuckle, being approximately 1.060" wide by 1.200" tall. A Knuckle port is round and 1.565" diameter stock.

Blower with both manifolds

Still, I might have concluded that the manifold was used on a Knuckle despite the size discrepancy were it not for the fact that the flange bolting the manifold to the blower is rectangular which limits the direction the blower could be mounted to facing forward or backward, but not sideways. That means that the pulley on the front of the blower would be at a right angle to crankshaft. Not very likely it would have been mounted in that orientation given the complications to driving the blower it would entail.

Another clue, is the fact that the gentleman I bought this blower from tells me that he also has a 2 speed racing transmission from the same dragbike. He told me that the trans case doubled as an oil tank. Very interesting! The size of the blower makes me think that a guy could tuck it in about the same space as a horseshoe oil tank would occupy. That would put the pulley on the blower in the same plane as the engine sprocket, making the drive comparatively simple. It would also explain the "S" shape of the carb to blower manifold. My guess is that there was originally a similarly fabricated manifold going from the blower to the heads.

More to come!

1 comment:

12345 said...

Do you still have the supercharger? I have an old Harley ironhead possible drag bike I would like you to look at via pictures? Maybe you can help me id some of the parts?