What Has 48 Cylinders, 2 Wheels, and 1 World Record? This Motorcycle.
World records can be wild feats of courage, exhibitions of mental fortitude, or the outcome of years of patient practice. They can also be a person concussing themselves by breaking open 49 watermelons with their head. Or marvels of engineering that carefully coordinate the movement of 48 pistons into a functional machine. Both the melon mashing and the multitudinous-piston motivation are real world records, and one of them can be yours if you play your cards right—no head slamming required.
This 48-cylinder creation—the official record for vehicle engine with the most cylinders—is the manifestation of Briton Simon Whitelock and is an exercise in solving problems to build the absurd. The project started in 1999 and seems to have been constructed in a typical UK workshop, which is to say a small shed packed full of stuff. Whitelock has posted videos of the build on a YouTube channel, and they are fascinating to watch.
Sixteen Kawasaki KH250 bikes, which were three-cylinder affairs, contributed their engines to this build. The original cases were cut to remove the transmissions and then welded together, forming inline-eight engines that were then stacked and lined up using large aluminum plates at either end. With three inline-eight two-stroke engines on each side, the rear mounting plate aligns the engines so they could be linked with a gear drive that feeds into a BMW K1000 transmission, and subsequently a shaft drive to power the rear wheel.
The front end is sourced from a Honda Goldwing, and the frame is more or less built around the engine. What looks like the fuel tank on top is actually a cover for the ignition and throttle cables, while a cylindrical aluminum gas tank is tucked down the center of the engine. A small fuel pump pushes fuel up to six carburetors that are mounted on manifolds at the front of the engine. Alongside the carbs sit the ignition systems, which are a mix of car and motorcycle parts.
The whole thing is a bit absurd, but we couldn’t help but be amazed when the massive engine—by our math it displaces 4200cc, or 256 cubic inches—fires to life. There is no way a human is going to kick start such a beast, and an electric starter might not have the oomph to keep the engine turning while the cylinders begin to fire.
That’s why Whitlock employed a donkey engine—a smaller second engine solely assigned to getting the six crankshafts spinning. A two-stroke mill pulled from a scooter, it’s linked to the output shaft by a one-way clutch and uses a slight gear reduction to get everything up to speed before it is shut off. The factory throttle tube’s choke lever has been repurposed to be a throttle for the donkey engine so the handlebars are still fairly tidy considering the complications happening behind it.
And yes, it does ride under its own power. In reality, though, running it for longer periods of time is likely a fool’s errand, as cooling all the cylinders appropriately would take even more engineering prowess than this build has already exhibited. Regardless, if you find this 48-cylinder wonder as intriguing as I do, you can raise a paddle and bid (its estimate is $51k-$76k) to make it yours late next month at the Bonhams Spring Stafford Sale in the U.K.
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Very cool! You’ve got to admire the engineering and fabrication skills that went into this bike…
Cool but we have a local here with a Gravely Tractor with I think 12 or 16 engines on it. LOL
I loved these deals as they do take a lot of work and this bike looks very well done.
Another one that was impressive was the three engined Honda drag bike Russ Collins raced in the 70’s. How he never killed himself was amazing.
Want to hear it run? https://youtu.be/6ratfuML9QA
Yes, it is absurd.
It has 5 more cylinders than my whole “fleet”.
The guy who did the final work on my Triumph built a two-engine Bonneville drag racer he called “The Parasite.” He still has it (or has it again, I’m not sure). Anyway, it’s a lovely machine. From what he said about the problems of synching up two twins, my mine boggles at the idea of getting the machine to perform.
That thing sounds crazy. Might be crazier than the Viper engine motorcycle Dodge did.
If I recall correctly Dan Gurneys ‘Alligator ‘ motorcycle used the idea of synching two engines only designed to work as one with twin crankshafts. A smoother running, called, ‘ moment cancelling’ , design. The basic idea being that two counter rotating masses would cancel each other out and eliminate the need for balance shafts etc.
I never heard the term ‘donkey engine’. we used to call the small gas engines that started the diesel engines on old Caterpillar bulldozers ‘pony motors’
“Donkey” = “Pony” in British. 😹