[Fot] Duke Engines

[Michael Porter]

On 3/22/2014 1:49 PM, Duncan Charlton wrote:
> Here is one that*is* new under the sun, different enough to have
> generated quite a few patents.  You can see it at: www.brickleyengine.com
>
>

I can see why he's getting resistance.  It's clever, but impractical.  
In the bottom end, he has twenty moving parts, whereas the normal 
four-cylinder has nine.  And, when he's doing his bearing drag 
calculations, he's conveniently ignoring that he has more than thirty 
bearing surfaces, where the traditional four-cylinder bottom end has 
thirteen.

If he's going to operate standard valves, he has to have some sort of 
camshaft to operate them, just like a traditional engine (not shown, 
likely because the arrangement would have to be rather complicated, 
given that the camshaft can't be placed at the centerline of the engine 
as in a flat four).  That problem might be solved by having a minimum of 
four overhead camshafts, one at each cylinder, run by a central chain 
off the crank, but that again raises the number of bearing surfaces and 
the number of moving parts, and it would be one helluva long chain and 
would require a complicated system of tensioners and guides.

He includes accessories in the friction calculations, but he'd still 
have to have them with his engine, so why are they factored in for the 
traditional engine, but not his? After all, one of the bigger 
losses--the oil pump--would have to be factored in for both.

The envelope doesn't seem to be very compact and would be ill-suited for 
automobiles, because it's evidently quite tall and wide (and gets bigger 
still when cylinder heads and valve gear are added). Structurally, it 
looks quite heavy, so I doubt that the rpm limit would be high enough 
for modern automobile use (that range might be extended a bit by using 
forged aluminum bits, at much increased cost).  I'm not sure I'd want to 
run it very fast, anyway, because the vibration from the multiple 
rocking couples set up by the piston arrangement and the reciprocating 
parts could hammer the rod bearings in short order.

It's a lot of complexity to get around one thing--friction caused by 
side loads on the piston due to connecting rod angular motion. That's 
the only real frictional gain this design achieves, at considerable 
expense, and that gain is probably erased by the losses incurred from 
the additional moving parts.


Cheers.

-- 


Michael Porter
Roswell, NM


Never let anyone drive you crazy when you know it's within walking distance....