Wallace L. Johnston
An Early Letter RE: Morgan Threewheelers
To: John Kitzmiller 7115 Vermillion Place Annandale, VA 22003
Your letter and the copies of the three-wheeled vehicle articles came today. Thanks for the through research and the pertinent questions. I will read and re-read the articles and, perhaps, by the time I convert this Word Perfect file to ASCII and send it by E-Mail, will have some additional insights. I am enclosing a copy of an article I got off the Internet - Quincy Enterprises - which has had several articles and plan offers in Mechanix Illustrated over the years.
I have also included copies of earlier correspondence I had from Jeff Stockton who has had a patented ( Feb 1993, # 5184842) front suspension design written up in Machine Design. I will try to address your questions and observations and bring you up to date on my project.
RANDOM THOUGHTS: (It is amazing how great minds follow the same logical pattern - until a "eureka" experience causes deviation)
1. As I may have mentioned in an earlier E-Mail - perhaps in one of the letters forwarded to show previous thinking - I wanted to have the look and feel of a MOG, BUT, the sliding pillar front suspension was cumbersome, prone to wear and not suitable for my purposes. I had originally considered using a Harley Davidson Big Twin engine, mated to a VW transaxle (reversed position a la Porsche 914) so as to have the VW flywheel and starter to the front where an adapter would join the HD engine main shaft. The engine does turn the correct way so as to have four speeds FORWARD and one reverse. This would require the VW ring gear in the differential to be "flopped" to the other side of the pinion gear to avoid the problem of four REVERSE speeds and one Forward speed.
Then there was the problem of how to get the VW transaxle to drive a chain to the rear wheel - Perhaps by locking the differential so the non-driving side would not spin while the chain sprocket side stood still?
I even considered using a hydraulic drive with a pump at the engine and a motor at the rear wheel driving the rear chain. The hydrostatic drive could also be reversed so as to provide a "back- up mode."
I gave up on the HD engine - too costly to obtain, too expensive to maintain and too rough running even when in tune. The staggered, out of phase firing order of the vertical twin configuration makes for a loping or un-even power output. It may be nice for the motorcycle rider who is into noise and vibration. There is also the problem of keeping such an engine - folks want to steal the things from each other.
After considering several Vee Twin configurations - Honda 500 cc, Moto Guzzi twin ( both of these are Vee to the wind, cooling surfaces facing the wind with the output shaft perpendicular to that). I also looked at several Vee twins which had the front-to- back placement similar to the HD, BUT, the problem with running the engine in that original configuration did not look "right" in the MOG and, turning the engine sideways was to present a hassle with the final drive shaft/chain.
My original thought was to un-shroud an air cooled VW engine and run it naked, a la BOW motorcycles, but was told that the engine, without the blower fan, would cook in short order. Perhaps that would work in a light airplane with a propeller to pass air over the cylinders, bun, not in a low speed automobile especially on a hot day in traffic, with stop lights.
Whatever engine I selected had to fit within the space limits imposed by the placement between the front wheels which had to move while steering and also travel up and down when the suspension was working. I considered a beam axle (Ford Truck and model "A"), Later Ford Twin I Beam, and finally selected the VW Super Beetle with the McPhereson strut modified to accept coil-over air shocks to incorporate the look and feel of the MOG suspension but, having modern brakes, rack and pinion steering and air adjustability. OR SO I THOUGHT. More on that later.
I decided that the engine of choice - available, affordable, "bullet proof", reasonable parts and maintenance, and powerful enough was the Honda Gold Wing. A flat four, water cooled, Engine and transmission in one housing with the starter in that unit AND having a clutch strong enough to handle the MOG configuration without slipping or burning up. ( After all, the true Gold Wing has all that fiberglass faring, radios, MAMA, a trailer or side car and still runs from 80 - 100,000 miles before overhauls. Harley can't do that!!!
I contacted a man in town who rebuilds GW's - salvage, wrecks whatever, and he built up a 1980 1100cc Wing (30,000 miles on the speed). His thought was to buy a running bike, ride it to be sure everything worked out ant transfer the engine to the MOG Replica at the proper time. If the car worked out - OK. If not, put the engine back in the bike and ride/sell it. So, for under $1,000, I have a new-to-me Gold Wing, all in one piece. Seemed better than chasing junkyard for a head here, a block there, carbs some other place and MAYBE, somehow, they can be made to work.
SUSPENSION: Front - Found a three part article in the KIT CAR mag about a man in California who had replicated the Morgan sliding pillar using modern re-circulating ball, linear industrial bearings on 1" smooth shafts. I was told by the bearing specialists that such a layout would produce heavy wear and "grooving" of the shaft - NOT GOOD.
The thought of using an older VW twin torsion bar set-up - common on Meyers Manx dune buggy applications - TOO HEAVY and too Not-MOG looking.
So, I started the initial machining of parts to adapt the Super beetle lower arms, brakes and R/P steering (from a Rabbit) retaining the look and feel of the MOG "steer horn" upper transverse member with heavy duty Heim Joints at each end to locate and support the top shock mounting post. In practice, the working length of the air shock to provide the travel necessary forced the placement of the transverse support tube far too high to be acceptable aesthetically and, as Jeff Stockton pointed out in his first reply letter " potential for very high degree of camber changes which would be accentuated by the one/two passenger loading factor and the inherent body roll found in many three-wheelers.
We discussed his Positive Linked Suspension System (PLSS) which was the subject of the Machine Design article. (I have enclosed his first letter and drawings for reference.)
After phone conversations I went into the shop at the university where I was constructing the body (Foam sandwich a la Dick Rutan Long-EZ pusher prop airplane) and made a working model of his PLSS with dimensions to fit my MOG track and frame lay out. IT WORKED! Better than I had imagined.
My biggest consideration was clearance between the spring mechanism and the bottom of the Honda GW engine which is front mounted, between the two front wheels. I was also concerned about the claims of " no shocks needed, no anti-sway bar used, no roll or lean, no spinout, no wheel lifting in hard cornering and no wandering due to side winds or crowned roads."
I took a trip to Arkansas City, KS to visit Mr Stockton and ride in a real car (his second) powered by a Honda 500 cc twin - motorcycle, less front wheel attached to a custom tubular frame with two passengers in front.
I was able to ride, drive, tale pictures and videos of the car in action. At my request, Jeff put the "Road Rat" into high speed lane changes on the highway (55- 60 MPH) NO SWAY, NO TIRE SLIP, No tendency to roll or dive. When I got to drive, we went down the highway to a local high school parking lot where I put it through a great deal of tight turns, accelerating and braking turns and lane swaps, and finally, cranked the steering into a tight, fixed radius circle and mashed the accelerator trying to get it to life a wheel or to break traction. I got dizzy, BUT the car never gave any indication of spinout, wheel lifting or loss of tire adhesion. Jeff indicated that a skid pan test on the Road Rat produced a .94 g rating.
It simply stuck to the road and did not exhibit any of the bad characteristics I had been expecting in a normal three-wheeler (If an 3-W is "normal")
No roll bar/anti-sway bar, no shocks just Jeff's PLSS suspension.
I got out and asked Jeff to put the car through its paces - rapid lane changes, acceleration, braking, swerving and tight radius acceleration and deceleration - while I captured it on video. Same results. It does everything it is supposed to do and nothing of the bad things three-wheelers are accused of doing.
I got back in the car, and videoed the trip over back streets to Jeff's residence/shop where I saw his third PLSS car under construction. I got 35mm stills and videos of the work underway.
On this iteration, Jeff is using Mustang II spindles, brakes and steering adapted to upper and lower"A" arms of his own design. (plans enclosed). The key seems to be the use of a single, transverse leaf spring which is held fixed on one end and acted on at the other by a pair of parallelogram links which twists the flat spring like a musician playing a hand saw with a violin bow (Sorry, that's the only way I can describe the action)
The leaf spring does not act like a diving board - there is no rebound, no resonant damping effect, no shocks, or auxiliary anti- sway bar. It simply and IMMEDIATELY transfers any movement of one end of the structure, ie, the lower "A" arm - to the other side. If the right wheel hits a 2" bump, the left wheel is un-loaded by a similar amount - IMMEDIATELY. There is no lag, no body roll with only the driver on board or with two passengers. It "squats" and goes on, no bounce, no hesitation. I was impressed.
Impressed enough to come back and re-configure the suspension and steering on my project car. I was able to find a 1980 Mercury Bobcat donor car ( same as Mustang II and Ford Pinto set up which is so popular with the Hot Rod guys) It has 9" dia. rotors and a 4 stud on 4.5" Bolt circle wheels BUT it can be upgraded to incorporate 11" dia. rotors for a heavier vehicle. I think mine will be about 1100 to 1300 lbs plus passengers.
By comparison Jeff's Road Rat is about 900 plus two hefty sized passengers and gasoline = about 1400 - 1500 lbs. Incidently, his car with the 500cc Honda twin would run an indicated 85 mph with us both on board on a level road.
I looked at the factory Mercury "A" arms - stamped metal, coil springs and shock absorbers and decided to fabricate tubular uppers - similar to the Heidts replacements for the Hot Rod trade. Their cost at approx. $1,400 - 2,000 is way out of my league, especially for my experimental adaptation.
I made ball joint mounting plates, tubular arms ending in aircraft grade Heim Joints for adjustment. The lower suspension members were 4" x 18" channel with 1" sides (bent up by my son-in-law out of 10 ga. steel) and were mated to 1" dia. steel bars which act as pivots supported by industrial pillow blocks. HELL FOR STOUT!!
It looks like a cross between Frankenstein and ROBOCOP (as influenced by the Brooklyn Bridge). I used a lot of Grade 8 bolts - mainly because I do not trust my welding AND because I wasn't sure that the parts would actually (and irrevocably) be where I first put them. GOOD IDEA!!
It is most assuredly OVER ENGINEERED. But, as my brother-in-law - an engineer - says, "Hammer to shape, Grind to fit and Paint to match."
As of today, I need to move the front cross member and its pillow blocks forward of the present location to achieve an acceptable caster angle. The alignment specs show .9 degrees with a =/- of .8 degrees. Because of my Kids Erector Set mentality, I can un-bolt. move, measure, re-drill and re-bolt when things get right. My call to Jeff indicates that a % degree caster angle on a non power steering vehicle of this approximate weight is more appropriate. Now I know where to drill the next set of bolt holes.
My original plan was to separate the GW engine from the rear shaft drive at the output shaft u-joint and simply re-locate the GW rear swing-arm and final drive unit which would then be connected by an extended drive shaft - about 48" or so. I did the design of the rear suspension unit, shock mounting points and appropriate pivot points for the newly re-located Honda swingarm. HOWEVER, it appeared that the driveline angle for the U-Joints would have been too severe at maximum deflection and the angled shaft would have intruded unto the passenger footwell.
So, I decided to make an intermediate drive shaft out of the back of the Honda engine ( the output is located off center to the right about 4" and about 4" above the bottom of the engine. Works well when the rear U-Joint is right there and held on by a circlip. This jackshaft would be directly above ( 5-6") and parallel to the real drive shaft located below the floor boards. Connection is to be with a cogged timing belt.
I decided to run the driveshaft from the rear U-Joint PARALLEL to the frame and below the floor boards. The front end of this shaft would be directly below the extended output jack shaft (all supported by my endless supply of 1" pillow blocks and connected by a cog belt timing drive (similar to the Harley Davidson Rubber band chain drive replacement) which could be 1:1 ratio OR could be another ratio if the performance characteristics were not quite right for the finished vehicle.
LATEST REAR CONFIGURATION:
After review, I decided that the Honda GW rear swingarm and final drive are too costly to subject to possible harm in this experimental application, SO, I went to the nearby junk yard and bought a SUZUKI 16" mag rear wheel, swingarm and shocks for $40.00. It has a hydraulic disk brake unit and a chain drive sprocket. It also has a nifty shock absorbing rear hub drive - six paddle shaped lugs which fit into rubber cushioned recesses in the mag wheel hub. All of this swings on a pivot through bolt and the rear wheel comes out by removing the axle nut and pulling out the axle itself.
AND, it all fits in the original rear suspension unit with their modified air shocks. The chain drive will be connected to a "T" drive unit (which I have on hand) which has 1" shafting, AND which will allow a centrally mounted driveshaft below the floorboards, with the same cog belt drive arrangement.
More Texas Aggie Engineering.
Any how, I am well on the way. I have read and re-read the stuff you sent. Some of the items are addressed above and some will be clearer when I send the stack of stuff I made for you today.
I will send this by E-Mail now. I will mail the package tomorrow and am making a video supplement for Jeff S. which shows the stuff I took at his house and some of my parts, bits and pieces.
Thank you for the interest and references. If you would like to talk by phone (I can talk faster than I can type AND the spelling errors are not visible.) Call (806) 373-7726 or E-Mail your number and we will talk over the weekend on my nickel. Also, send some background on what you do, and some of the things you have worked on in the past.
Wallace L. Johnston