Doggzilla
Well-Known Member
In another thread we are discussing how modern turbodiesels have finally met the same power to weight ratios of Lycoming engines, so maybe now is finally the time to discuss Deltic engines.
Deltic engines are engines with three cranks arranged in a triangle, with the cylinders pointed at one another in a set of 3 cylinders.
They have been operated in British naval vessels and Russian locomotives for more than half a century. So the design and concept is fairly well proven.
A Deltic could be created using existing off the shelf components from automotive turbodiesels. In another thread I used the Duramax diesel as an example, so Ill continue to use it.
A Deltic made from Durmax components would have 6 instead of 8 cylinders, so its power would be reduced to 300hp, and its weight would be reduced by almost 25% as well. It would use three twin cranks instead of one massive crankshaft. Almost identical to a Harley twin crank or Aprilia twin crank for our European members. Very similar load ratings as well.
As half the cylinders are removed (due to each pair of pistons sharing a cylinder), the weight of the "block" would be half as much as well. The combined weight savings would be no less than 35%.
This would provide a replacement for O-540 or O-360 class engines, while providing significantly better fuel economy and using significantly less expensive fuel.
The disadvantages are that its liquid cooled, shorter, and its drive shaft is centered, reducing prop clearance a few inches. Certain models of aircraft may be incompatible with it due to these limitations, and its performance may be reduced by having to use a smaller prop on certain aircraft that already have clearance limitations.
Deltic engines are engines with three cranks arranged in a triangle, with the cylinders pointed at one another in a set of 3 cylinders.
They have been operated in British naval vessels and Russian locomotives for more than half a century. So the design and concept is fairly well proven.
A Deltic could be created using existing off the shelf components from automotive turbodiesels. In another thread I used the Duramax diesel as an example, so Ill continue to use it.
A Deltic made from Durmax components would have 6 instead of 8 cylinders, so its power would be reduced to 300hp, and its weight would be reduced by almost 25% as well. It would use three twin cranks instead of one massive crankshaft. Almost identical to a Harley twin crank or Aprilia twin crank for our European members. Very similar load ratings as well.
As half the cylinders are removed (due to each pair of pistons sharing a cylinder), the weight of the "block" would be half as much as well. The combined weight savings would be no less than 35%.
This would provide a replacement for O-540 or O-360 class engines, while providing significantly better fuel economy and using significantly less expensive fuel.
The disadvantages are that its liquid cooled, shorter, and its drive shaft is centered, reducing prop clearance a few inches. Certain models of aircraft may be incompatible with it due to these limitations, and its performance may be reduced by having to use a smaller prop on certain aircraft that already have clearance limitations.
