Most people encounter this machine for the first time with a look of delayed wonder. I like that metaphor – a king or queen in peasant’s clothing. There’s an “Aha!” moment as you spot the third cylinder break through the down tubes. What is this peculiar machine, and what technical and engineering feats had to be overcome?
A mechanical marvel, without question, and historic, as this is the world’s first Harley-Davidson three-cylinder Shovelhead. It was copied much later – or I should say another example was made – by Jim Fueling, circa the 1990s. Bobby was just a one-man band working out of a two-car garage, making this feat only the more impressive. He was very much a clever man. His knowledge of engines was amazing. He had to do a lot internally to the connecting rods and cams, the timing of the three cylinders, and the machining of the factory cases to accept the third cylinder.
He also had to design an intake manifold that would be able to feed all three cylinders, fabricate an exhaust system, and modify the frame to allow space for that third cylinder. Actually, on this FXE Harley frame, Bobby grafted on a wishbone frame section (’50s-era Harley frame) coming down from the steering neck to allow the added cylinder to go between the down tubes. Bobby never spoke much in detail about what he did internally to the Shovelhead. A large part of his process remains a mystery.
Many stories and tales have circulated, and some will continue as Bobby intended. The one that comes to mind the most is how he did the motor internals – the rods and cams. On the connecting rods, we will continue the mystery as we haven’t been inside to look. My feeling is that if it isn’t broke, don’t fix it. On the cams, we can safely say this: Bobby was friends with John Andrews [of Andrews Products, producers of high-quality performance motorsports parts], and it was with his help and knowledge that they achieved the cams and timing.
One of the interesting stories, or possibly tales, was when Bobby was at the Harley Rendezvous showcasing his mechanical marvel for the first time. A rather overly cooked or partied out attendee was giving some lip to Bobby about that front cylinder being a dummy. Rather calm and cool, Bobby suggested to the individual that he grab ahold of that front header pipe and to let him know then if he thought it was phony. Needless to say, we know what happened wasn’t pretty.
My understanding, also, is that Bobby never really finished the third cylinder, at least not completely. When he was getting it ready for the first showing at the Harley Rendezvous in 1982, he had to borrow a front end off another motorcycle. It appears Bobby had a limited budget to work with, and that makes it even more intriguing. He also brought it to Daytona Beach Bike Week in March of 1983, presumably to turn heads at the Rats Hole motorcycle show.
Later, Bobby may have been approached by someone at Harley as they wanted to know exactly what he did to the inside of the engine. Bobby wouldn’t tell, and as the story goes, he was offered a big chunk of money for his creation. He didn’t let it go.
Another story that comes to mind was that the motor had been sabotaged. Fortunately, that was not the case. We have had it fired up, and hopefully soon, will get it on the road.
I think we’re all a little curious: what kind of performance gain does an additional cylinder like this provide?
The third cylinder increases the engine by an additional 600 cc’s or 37 cubic inches. With that, it’ll be smoother running, and probably faster off the line, but the overall top speed would be limited by its standard 4-speed transmission. With a total of 1800 cc’s and 111 cubic inches available at a twist of the throttle, I’m sure she has the power and torque to pull a Mack truck.
The sound, although, is not like you would imagine. The best way for me to describe it is to compare a Triumph Triple to a Triumph Twin. A Triumph Triple sounds like a Maserati, and the twin more like a “thump-thump.” Bobby’s intention, however, was not to increase speed, or comfort for that matter, but rather to show his ability as an engine wizard, and ultimately, to turn heads.