Centurion 128-mpg ... and smaller engines

[JackMcCornack]

Did you build the Centurion? And what does it rev to at 55?

Pretty cool; the only Centurion I know of (knew of, if this one's a different one) was the original prototype.

[changzuki]

>>>Did you build the Centurion?
--- Not originally. It was started roughly circa 1981, has been through a couple of owners but never completed. This summer, I've started rebuilding, replacing, or refabricating most of the car. The drivetrain has now been out twice, once after a homemade driveshaft went south - and that really made a mess! The body was off the frame for some re-engineering after a near catastrophe around the roof area (think Humpty-Dumpty's fate and that's the idea.) At that point I was ready to gut the drivetrain into something else, but this thing somehow deserves to be finished.

This summer the windshield was set for the 1st time and the rear side windows and rear hatch were fabricated. Once all the mechanicals are sound, then the body will be finished (most likely next year...) Or at this rate, Centurion really means it will take 100 years total to finish it.

I cannot give you an rpm @ any speed. Shortly after I got it, a poor connection and incorrect wiring at the main fuse block caused a major meltdown that back-tracked into the alternator (that supplied the tach pickup). After revamping the wiring, it now has a standard alternator on it and is awaiting a new tach that will pick it's signal up elsewhere. The parts that are now done are holding up extremely well over the last 1000 miles.

In three bags, every original blueprint, notes, newsletters and receipts exist starting from 1981. It's like the ultimate time capsule and I've continued to add to it. Oddly enough I still have the original Mechanix Illustrated magazine that ran the Centurion on the front cover in 1982. It was the only Magazine from the series I ever saved. I also never forgot it and used the basic theory when I converted the Changzuki to diesel back in 2005 or so. This returned 115 mpg both then and today (20,000 or so miles later.) I'm happy with both runs of 106 and 110 mpg on the Centurion but I am targeting the 115 mpg of the motorcycle. Will update from time-to-time as this progresses but with winter coming there's wood waiting, etc, etc..
~CrazyJerry

[Xist]

CrazyJerry, thank you for joining the site, and sharing your car with us. I understand that the car has a long nose (I want to call it a hood, but I do not feel that applies), a short windshield, and almost no angle between them, but the pictures look like extreme close ups. At some point, when you take a picture of the front, could you take it from standing height--if, you know, you are not already.

I think that would give it better perspective.

Does engine air flow around the bumper?

Thanks again and welcome to the site!

[changzuki]

Thank you for the welcome Xist.

>>At some point, when you take a picture of the front, could you take it from standing height--if, you know, you are not already.
----The interesting angle of the windshield makes the photos look a bit off. The photo directly above your posting is at standing height, no zoom, etc.. This is by all accounts a "recumbent car". In an earlier photo posted, you can see how the roof only comes up to the Accent's side mirror. The interior rear view mirror on the Centurion is mounted on the dash since it was essentially worthless on the windshield mount.

>>>Does engine air flow around the bumper?
-----The air intake for cooling enters directly below the bumper. The area is about 2-3 inches high and roughly 1.5 - 2 ft wide. That incoming air is then ducted into the radiator. An electric fan takes care of in-town cooling.

[changzuki]

As part of the project, this Centurion now has its own small space on the web. Probably will not make leaps and bounds anytime soon but will update from time to time. There's even a couple of video links at the bottom of the page. A 55 gallon drum was the camera man for the motion shots that's why there's no "zoom", etc... but the price was right!
~CrazyJerry
Urba Centurion 128 mpg Diesel Powered Car

[changzuki]

Originally Posted by JackMcCornack

Did you build the Centurion? And what does it rev to at 55?

Jack - Finally got the tach installed. At 55 mph I'm at about 2530-ish.. It just glides along at that speed!
~CrazyJerry

[rmay635703]

Given the random fuel delivery issues I've had with the Subaru 360 I often wonder if it wouldn't be easier in the long run to convert it to a 17-25hp diesel (car is 900lbs) Sadly though as geared you would turn 5k at 52mph, no idea how to fit a properly geared transaxle in this trailing arm wonder.

Ah well
Ryan

[changzuki]

Originally Posted by Ken Fry

My point was just that The Riley is not stunningly efficient by virtue of aero. 65 mph on 17 hp is not impressive.

Regards,

Ken

Ken, Actually having one as I do shows a different picture than theory. The car may not be "stunningly efficient by virtue of aero" as you say, but, 100+ mpg it is pulling (over 2000 miles now) so the magic must be elsewhere right?

Also, 65mpg on 17hp is not impressive, unless we stop for a moment and realize that when that little car hits 65 it is limited by the governor - 3060 rpm in this case. When it hits that limit you feel it stop pulling - so it still has power it's just rpm limited. A 454 with a blower and nitrous at 3000 rpm will still only go 65mph with the spitfire transmission and 3.89 differential. As an urban car with highway driving added (not interstate driving which we do not have around here) is perfectly suited.

Lastly, and not defending Riley, but a mile is a mile and a gallon is a gallon whether it is 1982 or 2012 - his figures are accurate for the plans - at least this build falls within those figures albeit on the high side. One thing not mentioned that few can - the Centurion will (on a variety of fuels) survive an EMP - something that pops up in the news and science shows from time to time.
Back to more refining.
~CrazyJerry

[changzuki]

Originally Posted by rmay635703

Given the random fuel delivery issues I've had with the Subaru 360 I often wonder if it wouldn't be easier in the long run to convert it to a 17-25hp diesel (car is 900lbs) Sadly though as geared you would turn 5k at 52mph, no idea how to fit a properly geared transaxle in this trailing arm wonder.

Ah well
Ryan

Ryan, Believe it or not I though that scenario awhile ago. Aside from physical space issues, the Subaru 360 would likely run into issues with the diesel vibration unless you were to fabricate a different engine mounting subframe of sorts... I ended up with a Honda Z600 thinking I'd diesel-ize that too but decided against it mostly for the same reasons. If you really decided to heave-ho the gas engine and went with Lithium, your 360 could really be hotttt! At least I could see it...
~CrazyJerry

[rmay635703]

Originally Posted by changzuki

Ryan, Believe it or not I though that scenario awhile ago. Aside from physical space issues, the Subaru 360 would likely run into issues with the diesel vibration unless you were to fabricate a different engine mounting subframe of sorts... I ended up with a Honda Z600 thinking I'd diesel-ize that too but decided against it mostly for the same reasons. If you really decided to heave-ho the gas engine and went with Lithium, your 360 could really be hotttt! At least I could see it...
~CrazyJerry

The one EV subaru 360 I know of does 40-60 miles on a smallish 40ahr lithium pack.