Hitchcocks Forum

Hi, does anyone know how the engines on the Don Sliger double engined speed record interceptor were coupled on the timing side by gears? I'm curious how the oiling system worked! Vince

I read about this sometime ago in a US magazine. The crankshafts are coupled on the primary side by chain with an additional chain to the clutch, interestingly a scissor clutch. For some reason it is also coupled on the timing side by gears. As i recall the gears sit outboard of the timing covers and the engine using the standard timing with 2 mags and standard oil pump setup. Not sure what benefit this had, maybe they kept breaking the primary chains. Strange as most other twin engined record bikes seem to manage with just a chain. Richard

Why would the chain linking the two engines need to take any more force than in a single engined set up. Surely it would only need to transmit the power from the front engine. The chain from the rear engine to the gearbox would need to transmit the power from both engines, but I can't see why gears joining the two engines together on the timing side would take any strain off the chain to the gearbox. It would be interesting to inside the covers.

Hi, I heard of this chain problem before on coupled engines, they have to have all cylinders at tdc together or the power pulses destroy the chain??? An Ariel square four is a geared coupled engine. I'm intrigued how the gears are powered through the timing cover and still allow the oil feed to work. I would have though it far easier to fit gears on drive side! What is under that cover? Vince