Duke Engines – Time for a NEW FORMAT?

[G. David Felt]

G. David Felt
Alternative Fuels & Propulsion writer
www.CheersandGears.com

 

Duke Engines – Time for a NEW FORMAT?

 

 

A 5-cylinder Axial engine at 1,000cc size begs the question: Is this the future of motorcycle and auto engines or just a wild idea like the Mazda Rotary? Duke Engines has been playing with outside the box engine design for some time. They play in the markets of Marine with inboard and outboard engines to aircraft and AC generators.

 

They recently are using their Axial engine design to play in the Range Extender market for hybrid auto’s with a thought of the VOLT style car, electric driven auto with a generator to produce electricity for long range drives as well as the motorcycle market.

 

So what does a Duke Engine offer over traditional 60 degree, 90 degree v engines or straight 4/6 cylinder engines? Duke says that their Axial engine offer No Vibration, High Power that leads to considerable reduced size and weight. Performance lovers will love the high power to weight ratio or density that the Duke Engine brings.

 

https://www.youtube.com/watch?v=cTpPBiReaZk

 

The base engine at 1,000cc gives you 125hp and 20% more torque than the same size conventional engine with much fewer moving parts according to their web site.

 

https://www.youtube.com/watch?v=c19kn3drdFU

 

These compact Axial engine design is akin to the shape of current electric motors. Their current 3.0L prototype engine has been tested up to 4500rpm putting out 215hp and 250lb of torque.

 

Duke Engine put together this FAQ page.

 

Frequently Asked Questions

 

So with this truly unique design on engines, is this the future for GAS, Diesel, CNG engines / generators?

 

Does this make sense to use this in the next generation of Volt Type hybrid auto’s?

 

Would you drive a motorcycle with an Axial engine?

 

Leave your thoughts on what you think of this new engine design?

 

Could this be the new Small Block V8 pushrod replacement that the world is looking for?

[Drew Dowdell]

Likely much slower to Rev than a conventional engine limiting it to the role of a regenerater

[G. David Felt]

Likely much slower to Rev than a conventional engine limiting it to the role of a regenerater

But the web site says it revs 20% faster than conventional V type engines.

[dwightlooi]

This is actually nothing new. In fact, this is the dominant engine format for torpedo engines. In fact, the US Navy's current heavy weight torpedo and light weight torpedoes -- the 533mm Mk48, the 324 mm Mk46 and Mk54 -- uses exactly this type of engine. The difference of course is that the torpedo engine runs on Otto Fuel -- an air independent fuel-oxidizer mono-propellant -- not gasoline or diesel as is expected of automotive applications.

 

That this type of engine is vibration free is not true. It just doesn't have vibrations perpendicular to the drive shaft like most automotive engines. The engine does vibrate along the axis of the output shaft. More importantly, the design has high frictional loads and difficulty with lubrication from the need to convert axial forces into rotational forces via a swash plate and multi-axis bearing loads. Think of the swash plate as a wobbly disc. The pistons are connected to it via rods that ride up and down this wavy disc like ponies in a merry go round. There is also the problem with maintaining a gas seal over prolonged usage where the top of the cylinders slide past intake and exhaust ports sequentially. A good way to picture this problem will be imagining a traditional inline engine where the cylinder head must slide past the top of the block once per revolution and having to create a head gasket that keeps its seal while the head and the block are sliding past each other.

 

Traditionally, axial engines are used in high efficiency, high power density, expendable engines. Obviously, engine component longevity and reliable service for 200,000~300,000 miles is not a concern for torpedoes which only needs to make one one-way trip of no more than 40 miles. That said, if you can make an axial engine live as long as a traditional (perpendicularly reciprocating) engine it does have compelling packaging power density advantages. Still, if you are looking for the highest power density and the lowest maintenance requirements, there is always the turbine engine which has the highest power density, lowest weight, is by definition air cooled, has as few as one moving part, coolant-less and truly has no vibrational forces. Turbine engines -- especially turbo electric turbine generators -- are also truly multi-fuel because their compression ratio is completely dependent on the operating speed. Hence, switching from gasoline to kerosene to diesel is as easy as changing the speed at which you run the generator.

Edited December 31, 2014 by dwightlooi

[G. David Felt]

Very cool, great input Dwight, glad to have you comment on this.

[RobertNick]

It may not be something very new, but all it takes is someone to show it can pe profitable. They seem to be on the good track with this. For now.