Massive 124-cu.in. V-twin powers steel-bodied roadster
A flathead Ford V-8 would’ve worked just fine. This was Tom Harris’s first hot rod, after all, and the sheer number of experts and parts for those engines would’ve made building and installing one as easy as tripping. Besides, his uncle used to race flathead-powered sprint cars all over the Midwest in the Thirties, so a flathead would’ve provided a kind of family connection that would make the car special. But Tom wanted something even more meaningful to him under the hot rod’s hood, and only a Harley-Davidson V-twin would do.
“I’m a motorcycle guy first,” he said. “From the time I was in my teens, when I started in Triumphs riding on dirt, to when I got into Harleys and road bikes, I just love motorcycles.”
In fact, he had a 2004 Harley Softail in rough shape in the garage, and as he got to looking at it more he started to think that the Twin Cam in it just might work in his hot rod. With a few improvements, of course.
“There’s not a lot of Harley-Davidson left in it,” he admitted
The 88-cu.in. Twin Cam engine in stock trim puts out 62 horsepower, just a few shy of the 65 horsepower that the 1932 Ford Model 18’s 221-cu.in. V-8 produced. Given that it’s lighter by six cylinders and its air-cooled nature meant Tom wouldn’t have to include the weight of a cooling system, the Twin Cam could conceivably have powered the hot rod just as well as a flathead. But “just as well” doesn’t sit well with any hot rodder, so Tom had the case machined to accept a bigger crankshaft and S&S heads that enlarged the Twin Cam to 124 cubic inches and, fed by a 55mm throttle-body and a 60psi Holley fuel pump, produced a dyno-tested 140 horsepower and 140 pound-feet of torque.
“I could’ve gone larger with a wild cam, but I wanted the engine to live,” he said.
Key to making the bigger engine reliable was providing support for the heads, Tom noted. Boring those Twin Cams out by that much can cause the heads to leak where they mate to the case, so Tom fabricated a superstructure that goes up and over the V-twin and connects it to the chassis to mimic the Harley’s frame.
As opposed to the Hot Rod Hawg and various other Harley-powered hot rods, Jeeps, and Volkswagens that place the engine with the crankshaft longitudinal to the car, Tom chose to mount the engine in its traditional transverse configuration. That meant running a chain from the Baker DD5 five-speed with reverse transmission to a Tandler right-angle gearbox, which then turns the driveshaft that connects to the Winters quick-change rear axle. All of this mounts in a 1932 Ford chassis from Brookville, the same company that supplied the steel 1932 Ford roadster body. Shifting is accomplished with a cable running from the clutch pedal to the Baker King Kong Clutch and an in-and-out shift rod that pokes through the firewall. Fuel is stored in a Freightliner 10-gallon air tank.
One advantage to the Harley V-twin, Tom noted, is that it takes up less space fore and aft than a V-8 and its radiator, even when the V-Twin’s mounted transverse. As a result, when he ordered the body from Brookville, he specified the firewall that would give him the greatest amount of legroom. Much of the rest of the body and chassis is fairly standard street rod fare with a Pete & Jake’s four-inch-drop front axle, Wildwood disc brakes, Ridetech shocks, a Limeworks steering column, Sid Chavers Bop Top, Lokar parking brake, Glide Engineering seat, and Rocket wheels.