Ducati V-8

Intriguing

http://thekneeslider.com/archives/2010/10/14/ducati-elenore-v8-update/

Does anyone see the advantage of this over a comparable disp. engine with less cylinders? The 4 cy. sounds great but doesn't show impressive acceleration. I didn't see what the disp. of the V8 is.

Intriguing, but overly complicated. Give me a rotary-powered Norton, please.

That is thinking outside the box! Graefin10: you get more power pulses per revolution, so the engine should feel smoother, as is the rule with more cylinders for any given displacement.

It should have the low rpm torque a rotary Norton wouldn't have.

With 6 fewer connecting rods, reducing the reciprocating mass, it should rev quickly--provided the "rockers" that connect the pistons are lighter than comprable rods. .

Some of the links are very short and swing through a large angle. I'm worried that the bearings on those links will take a real beating. I must say, it's quite a creative design though.

mike wrote: Some of the links are very short and swing through a large angle. I'm worried that the bearings on those links will take a real beating. I must say, it's quite a creative design though.

I'm also worried about those pivot bearings. They have to be using a semi-hydrodynamic lubrication regime because the mechanism doesn't create the required rotational speed to use a typical journal bearing. They can't use a ball bearing because the film thickness is too thin to absorb the shock from the combustion cycle. I'd like to see what kind of longevity they expect out of the engine.

canoe

YaNi wrote:

mike wrote: Some of the links are very short and swing through a large angle. I'm worried that the bearings on those links will take a real beating. I must say, it's quite a creative design though.

I'm also worried about those pivot bearings. They have to be using a semi-hydrodynamic lubrication regime because the mechanism doesn't create the required rotational speed to use a typical journal bearing. They can't use a ball bearing because the film thickness is too thin to absorb the shock from the combustion cycle. I'd like to see what kind of longevity they expect out of the engine.

Perhaps they are using needle bearings for these, much like two-stroke wrist pins. I agree that a full hydrodynamic bearing is not feasible. It is generally not possible to make that kind of bearing work for reversing elements. However, most wrist pins are splash-fed plain bearings, so perhaps that would be good enough here as well. At any rate, it looks iffy from a longevity standpoint.