Urba Centurion Update - (Kubota diesel, 100+ MPG in mixed driving - Fall 2012 on)

[changzuki]

Originally Posted by Xist

What a gorgeous paint job! Looks like an ice rink!
~CrazyJerry

[changzuki]

With the cold mornings the recent heater hookup was a welcome addition - however - victory was brief! The Centurion's fan motor made some amazing noises before screeching to a halt.
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Removing the entire unit is not messy and it's not hard if you're a contortionist. Upon closer inspection, the 1966 Smiths motor had so much play in the shaft, the fan blades were contacting the metal shroud - eek! .
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Most of our vintage junkyards dried up long ago but luckily we have internet. I found a comparable size motor, same shaft size and about 3 grains of sand difference in the bolt pattern.
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After installation, all went well for several on-off runs. Then more noises. The fan attaches to the motor shaft via plastic threads and a plastic nut. When tightened the threads are allowed to clamp (squeeze) the shaft to secure the fan. The problem now was the instant torque of the new motor would break the grip just enough to jar the fan's alignment a little each time, ultimately over several start-stops, making it shift enough to contact the heater housing. There is very little wiggle room so the fan must stay in position on the shaft.
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So, back to the internet. The solution ended up as a PWM control for the motor. This now allows for a slow start-up and then variable control thereafter. Unlike the older resistance based controls, there is no appreciable heat generated when setting the speed of the motor. Very nice! There is also a second PWM for the separate fresh air/vent system.
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Until the next issue - I shall enjoy PWM control on the heater. Onward!
~CrazyJerry

[changzuki]

Lately there's been lots of news about fireballs in and around the east coast. Over 120 in one night last week!
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Then there's the coronal holes in the sun that are linked with the recent quakes in the ring of fire.
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And tonight (Sunday October 20th) is supposed to be the peak of a meteor shower (likely the remnants of Halley's Comet..)
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So this got me daydreaming that in the event of an EMP strong enough disrupt all of our beloved electronic gadgetry, where would that leave us?
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Hopefully we'll never have to find out, but the Centurion may very well be one of the EMP Surviving Mad Max's barreling down the barren roads. Is this really so far-fetched?
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Below is a photo of an empty dealership lot... And the Centurion....
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~CrazyJerry

[Xist]

Originally Posted by changzuki

Below is a photo of an empty dealership lot... And the Centurion....



~CrazyJerry

Old Honda place?

I think that your car would need 10,000% more knives and other bladed weapons on the front, at least.

[changzuki]

>>>Old Honda place?
----Yes! It was quite nice when built and I don't believe a new Honda ever was sold there... Now the building stands vacant..
~CrazyJerry

[changzuki]

As the weather changes up here in Northern NY we find ourselves battling a rollercoaster of passing fronts.
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On the plus side, being online can help to pass the minutes if one has the time - that is unless you get inundated with the perpetual Windows updates (and any other software updates you may have.)
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So rather than get all bent about it I decided to do something about it, sort of like "if you can't beat'em join'em".
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After many hours of tinkering the following is my absolute favorite windows update:
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ThanKs Darin!
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~CrazyJerry

[changzuki]

Bombshell! The Urba Centurion Parked Next To:
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~CrazyJerry

[Ang84Indy]

Nice Tri-Magnum! I love those things. You finally found something similar in size to your Centurian.

[changzuki]

Originally Posted by Ang84Indy

Nice Tri-Magnum! I love those things. You finally found something similar in size to your Centurian.

Thanks ANG84Indy. Yeah, it's not what you'd call very big but Large Marge does tower over the Centurion!

~CrazyJerry

[rqriley]

Gentlemen, I was happy to run across your thread on Centurion. I am one of two original designers of Centurion - built at my former design firm in Phoenix AZ, Quincy-Lynn Enterprises. I was responsible for the engineering and participated in the styling and the actual build. I can confirm that the figure of 128 mpg is accurate for our vehicle. We tested for mpg on a little used highway north of Phoenix. We disconnected the fuel line from the tank and ran a hose to the fuel pump from a beaker inside the cabin. The beaker held enough fuel for about 5 to 8 miles. The roadway was on a slight grade, so we ran up the grade until the beaker was empty, filled the beaker, and then turned around and ran down the grade. It was just a slight grade. We ran five or six times in both directions and recorded the distance until fuel had been used in each direction. We then averaged fuel consumption and distance and calculate the result at slightly over 128 mpg. Each run included one acceleration to speed, and then a steady-state run at 35 mph until the beaker was empty. That's where the 35 mph fuel economy figure came from.

I don't have a clue why that other Centurion was only getting 45 mpg. In my opinion it would be virtually impossible to get fuel economy that poor with a Centurion built according to plans. Something must be costing him lots of energy with that vehicle. If you first take care of aerodynamic drag and vehicle mass, and make sure the brakes aren't dragging, then the key to high fuel economy is to be able to load the engine into its region of lowest bsfc (brake specific fuel consumption). That normally happens with a diesel engine when it's loaded to about 60 or 70 percent of full load. You do that with tall gearing, and then down-shift for acceleration.

I noticed some discussion about parasitic drag - water pump, alternator, etc. We did not do anything in that regard with the original Centurion. We left the parasitic drag alone - just as Kubota had designed it. We did use low-viscosity lubricants, however - to avoid too much churning in the transmission and final drive.

And if you can afford it, I'd recommend experimenting with turbocharging. Diesels love turbocharging, and it normally results in more power and lower fuel consumption.

I'm glad to see that you are taking it up a notch with the details. There were lots of things that we did not do with that original vehicle - we knew what they were but we just did not do everything we knew.

Good luck. And I'll try to come by again. My biggest problem is that I seem to be always overloaded with work.