Biodiesel Cushman Three wheeler

http://www.youtube.com/watch?v=H4LlH1arq2E

Here's an old page of how and why we modified the Truckster. The 'Truckster' has been around the shop for quite a while now, and it gets used a bunch to run neighborhood errands. Yard trimmings, branches, and leaves, much of it is hauled to Otey's compost. I did bring home a Listeroid in a crate once, and as you can imagine, that's a load all right. As for the interest in a conversion kit? I think I heard from three people who were interested. If you decide to make an adapter, I think the answer is the plasma cutter, cutting out two rings, and welding in some spacers between, then jig it, and locate holes on both ends.

To rationalize my effort further, Vehicles like my pickup burn a lot of fuel when cold and those short drives to a nearby neighbor and return might cost you $5. Short errands are numerous, and the Truckster does them for pennies. Of course this vehicle would drive most progressives crazy, it doesn't meet the bumper standards, no air bags, you could burn untaxed fuel, fact is... you just should be allowed to own something like this...   

Above:  The Veggie burning Cushman starts taking shape, front sheet metal is not yet fitted.

Above: Prototype exhaust is fabricated from two 90 degree exhaust pipe bends, the utterpower laser cut 186 exhaust flange, and the stock muffler was mounted with upper and lower supports off the power train.

Above: The Yanmar clone does indeed fit into the Cushman engine compartment.

Peakoilmobile ?

Just how far will a Cushman 3 wheeler go on a gallon of Biodiesel?

I have a Golf cart at Easton that I use to pull a mower deck around our 5 acres of mowed pasture. It is fuel efficient, and if I told you how far I've had thing thing up in the mountains, you would not believe! One time I was about half way to Goat peak, and came across a family of four on Quads, they were all decked out in helmets and riding suits, (all matching) and thought they were far away from it all.  when I rode thru in the golf cart with a cold beverage in the drink holder; they were dumb founded! Problem is, the golf cart is a little down on power, and has a top speed of 15MPH down hill. Furthermore, it doesn't haul enough stuff, and it's a gas burner. (hard to store present day gasoline as it can oxidize rapidally.     

 If you have looked over the little Cushman three wheelers, you'll note that they are tough, and they are light weight, if Petrol goes up to $4 to $6 a gallon, maybe a diesel powered Cushman with a pickup bed would make sense for running around the ranch, mending fences or doing other chores. Heck, a guy might even go into town and pick up groceries with such a vehicle if he's going to save big on fuel.  

 If this works the way I think, we'll look into providing the conversion pieces. This particular engine has electric start, and a charger built in, this makes it pretty easy to drop in the Cushman. There are plenty of dead Cushman's around, companies write them off the books and buy new, the engines are expensive to rebuild, and the Yanmar clone repower might interest those who are interested in biofuels.

If you saw the article on the Chevy Metro, you'll know this is a gutsy little engine with plenty of torque.

I hired Chuck McGhee to build the prototype adapter out of a solid piece of two inch steel plate 9 inches in diameter.

 First Driving Impressions

 Finally the drive train was complete, no throttle, no seat, lots of stuff not hooked up, but I could no resist taking it around the block to Allmand's place. 

I put a furnace filter across the top of the engine and used it for a temporary seat, The engine started up first attempt after adding lube oil and fuel. It sounds like a serious work horse.

I set the engine at about 1500 RPMs, and let the clutch out slowly, we were off! the torque is unreal, and once in third, I opened the throttle some more, wow, we're rolling along pretty good, must be doing about 3 times what the golf cart does tops. Got a corner coming up and with no brakes, maybe we better back off the throttle?

I turn down Randy's road, and open up the throttle in second, we are now spinning the wheels in the gravel! We have plenty of power for sure, I imagine what it's going to be like with the gas pedal hooked up.

Randy comes to the door, looks out and shakes his head, no seat, no brakes, and a crazed diesel head behind the wheel..

This little engine will not get any points for quiet idle, but it will pull hard, and I bet it will be a long time between fill ups.. once off idle, it quiets down and sounds more a little more like a typical 4 stroke.

As for the adapter kits, just called McGhee, I think this install is so easy, that others will want to follow, the stock front motor mounts were reused, as I made a simple plate to pick up the front engine mounting holes, and the stock mounts, it all looks factory stock to me, and that's usually a sign you did it right, and I can say that it meets the KISS engineering principle. the kit will contain only three main pieces, that's the front mounting plate, the adapter between the engine and clutch housing, and the specially designed collar to carry the flywheel on the Yanmar clone shaft. 

I will get the pickup bed back on, and do some real testing, more to follow..

I think this is going to make an excellent Farm vehicle, and you might forget when you last filled it up with fuel.

More to follow, I can't wait to take this to the top of some mountain out of Easton, that'll be the real test!

The side panel lifts out, and access to the pull starter is quite good, this is a bonus feature over the stock Cushman power plants I've seen.

A couple of  things I found interesting about Junker Cushmans, they look hard to kill, and very rebuild able, there is one thing you need to know, that is pulling a wheel hub will stop you in your tracks! using and off the shelf wheel puller might not do it either, and several setups left me wondering just what it would take to pull the hubs! I tired a different hub just to be sure I didn't have just one that was really messed up.

Finally, I took steel bar stock one inch by one inch and made a puller.

Above: Here's a crude drawing of the puller I HAD to make, the ends were milled down so I could drill holes to pick up two lug bolts, and I counter sunk the tops to take the stock lug nuts. The blind hole in the center receives the threaded end of the axle, best to center a ball bearing to assure threads are not crushed. If you need more clearance, just place a washer in the center hole. The first wheel hub I pulled let go right about the time I thought I was going to break a lug bolt in half! this was after using WD40, tapping the end of the axle with a big hammer, and a good many other tricks; including a little heat! What is required is a stout puller, and all four hubs I pulled off (two different rear ends, were all really on there. The hub is on a taper, and the axles are keyed, never seen them this hard to pull, but four of them were tougher than most off the shelf pullers (I've had access to) could muster!

As for the rest of the Cushman stuff, it's pretty basic and straight forward, and I didn't find any other surprises.

08-31-05

 I have the brakes working after buying a new master cylinder and wheel cylinders, the wheel cylinders were hard to find and $50 each after sales tax here. Getting into Cushman brakes can be expensive. With the brakes hooked up, and the engine cowling and pickup box on, I was ready to start it.

I love diesels because they can set for a long time, and still start easy. I've had far too many gas engines that needed the points retouched, shorted condensers replaced, and carbs taken apart and cleaned or replaced to get the darned thing running. Come to think of it, gas engines don't have to set very long to start hard, modern electronics does make it far nicer, but I recently had an expensive JD lawn mower stop running and the little module cost more than what I thought the whole lawn mower was worth, you guessed it, I took it down and threw it on the pile at Binford Salvage in Kent. That shiny looking lawn mower sitting on top of a pile of metal trash and other throwaways was a profound statement regarding our present society.   

Since I haven't rebuilt the battery box yet, it's time for a manual start, the Cushman side cover lifts off the engine box, and it's fairly easy, I found that the decompressor can be depressed part way and will stay there, one pull on the recoil starter and the valve movement drops the decompressor in semi auto fashion. As normal with the better quality Yanmar clones, it was an easy one pull start.

The Cushman was ready to go. I left the drive way thinking about the last time I had seen a patrol car, as I leave the shop drive way, the engine lugs more than I expect, but it chuffs away, in a second, I realize I just made a third gear start, I quickly find first on the column. As I near the end of our little dead end street, I prepare to turn right on 144th, this time I leave in first gear :-) The Cushman is far quieter with the engine box in place, and there's room for insulation to deaden it more if it becomes important.  I opened the throttle, 2nd gear pulled well, and I noted how well the governor functions as we reach the 3600 RPM redline of the engine, this is 600 more RPMs than the little 8hp Kohler that powered many of the earlier 3 wheelers. It was time for third gear, no traffic; and most normal people are at work, I leave my foot in it. At 45mph, we have not yet reached the end of the Governor, I look down at the front tire and see that it is now in serious oscillations, the tire is square from sitting for many years in one spot.

I started down Allmand's long country lane, I slowed down to assure I didn't leave a wake of dust, a smile came over my face as I counted the exhaust notes at about 15mph, this little engine has so much torque, and the gears seem to be well matched for this little utility vehicle. As I pull up to Randy's place, I am pleased to know that the Yanmar Clone, and the Cushman seem to be most compatible. I have a file for this project, and I am compiling cad drawings for the very few conversion pieces that are required. The next piece to make is an exhaust flange that will allow us to get rid of the stock muffler just under the seat cushion, I will route the exhaust exactly as Cushman did on the Kohler, or as close as possible.

When Randy comes out of the house, he notes that I am delivering his MIG welder, this little pick up box is pretty handy, as I prepare to turn around in front of his garage, I decide to crank the wheel hard and see if I can make a tight U turn, sure enough, and no wonder those Meter Maids everywhere used Cushmans, they turn around on a dime, I'll bet the reverse gear in this thing was seldom used. As I unload the welder at Randy's shop, I tell him about Jerry Bartlett in upper State New York. Jerry put this same engine in an old Japanese motorcycle, and fitted a CVT like that in a snow mobile. Jerry reports he's averaging 110MPG on his first 4000 miles logged, and I'm sure much of that was logged on twisty roads, and less than flat terrain.

Randy and I find time to drink a beer, (I'm good for one at most), we settle in the cubby hole office, I look at the pictures of hot rods on the walls, the

Mikita poster girl is always worth a look, and that complicated part on the shelf, Randy scraped it after putting about 4 days of work into it, it's there as a reminder to measure twice, and cut once, I need to look at it often.

As I arrive back at my shop, I lift the seat cover, and hit the compression release, the engine goes silent. The Cushman has been transformed from Junk, to a functional and useful vehicle. I decide to give it a place out of the weather in my already crowed shop, as I push it up over the edge of the cement floor, I note just how light, and how easily it rolls. I have a 400cc Artic Cat Quad that takes serious effort to roll in here, and this rig rolls in with one fifth the effort!

If I was forced to enter a bet on what this little vehicle could knock down in the way of mileage, I'd be looking at a number of 90MPG+ at 30-35 mile an hour. This vehicle weighs a fraction of what the GEO Metro weighs, and the rolling resistance is way down, maybe three wheels are an advantage in this respect? We know the Cushman is not exactly slippery as far as a drag coefficient, but if a guy wanted to play around, he could 'fair in' the front, sure it's a waste of time if you have cheap fuel and no place to go, but those days may be gone, time will tell.

 And now back to our Cushman story...

So why is it you modify a Cushman Truckster like this? Like a lot of things these days, rebuilding the stock engine might cost you twice what the vehicle will be worth when you're done.

So you're too green for Biodiesel? Well then, add pedals, add batteries, make yours to run on hydrogen. Better yet, visit the free energy WEbsites and learn how you can harness the power of spinning magnets.    

See this engine in Jerry's Motorcycle

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