This section is for the hardcore “GEARHEAD”. If you do not fit this description, then I must ask you to move to another department of this website, as this dept. will get very in depth with technical things. Maybe even geometry and physics will be discussed. Still here? I’ll give you one last warning, all of these things, including chemistry, will be talked about before we are finished.
We’re going where only the stout of heart have ever been. Prepare yourself for an excursion into the mechanics of the B.A. Truck. As you read about the mechanical parts of the B.A. Truck, the corresponding pictures can be seen in the photo section.
     Where to start? Perhaps at the beginning, or foundation, the frame. Most competitors would use a frame (ladder style) with side rails of 2”x4”x1/4” wall thickness rectangular tubing. We chose to make our side rails 2”x6”x1/4” for the sake of extra rigidity in the overall frame structure, without the concern of a competitor for the added weight, for the purpose of controlling engine/ driveline torque. When a vehicle does a wheel stand, the torque from the engine makes it want to spin like a top on its rear tires (the B A Truck has skid shoes attached to each of the two frame rails for the purpose of limiting the angle of truck to track at a maximum of 30 degrees). This type of gyroscopic action (caused by radial torque) is dangerous and must be avoided, for the sake of both spectator and driver.
The other component of radial torque in the chassis is the rear axle assembly. We chose to use an axle of planetary construction which would allow sufficient total ratio, without having a high numerical ring and pinion or transmission ratio, as either of these would add to radial torque. A great deal of lift torque is needed to produce wheel stands, but with a minimum of radial torque as to allow control of the vehicle.
     Radial torque is what causes the left tire to get more traction than the right does. In a pulling situation this causes the vehicle to veer or pull to the right, a very bad thing when your front tires are six feet off the ground! Torque multiplies with gear ratio but where that ratio is placed along the line of power can make an immense difference in how the chassis hooks-up and handles on the track. The planetary gearboxes on the axle housing add to the lift torque while minimizing radial torque. None of this is myth or supposition; it’s simply a matter of physics. Remember this simple adage; “for every action there is any opposite and equal reaction”, think through the forces being applied before you settle on a plan, we did.
Now that we have declared the accolades of a planetary rear axle, we must consider any negatives associated with this configuration. The drawbacks are obvious but not numerous nor something that cannot be overcome. They are weight (rotating mass) and inherent friction, (caused by thrust within the assembly). The basic design of planets dictates an increase of friction, while the addition of gears with their corresponding housings will add weight.
The weight/ rotating mass issue can be addressed by having components made of lightweight materials such as aluminum or magnesium. We did not choose to have such lightweight components made for two reasons. The first is cost, such pieces can be expensive and we are a non-profit with limited funds (donations). The second is that our runs are smooth and progressive so the extra mass will not affect our performance.
     Friction was a major concern for us because of the need to make extra power to overcome it. As all racers know, the more power, the shorter the lifespan of their expensive motors. This problem of friction was dealt a mighty blow by the folks at MicroBlue Racing. Craig LeClaire (of MBR) offered to donate his services to eliminate this nasty problem of friction. It seems that the best way to deal with this problem is to simply change the way in which lubricants work. It is really very simple, first the surface is prepared with an isotropic surface finish, and then it is coated with tungsten disulfide. The tungsten disulfide acts as a surfactant breaking down the surface tension of your lubricant making the lubricant much more slippery in relation to your moving parts. It’s really very simple! This particular process is the only one (that I have found) that has no downside. Whenever a racer confronts an issue, there is always a negative involved (you cannot have your cake and eat it too), sorry for the cliché, but it’s almost true. It is possible to dramatically reduce your frictional loses (by 70%) and increase the lifespan of components that are already being stressed to the max. Conclusion; you can have your cake and consume it also! When you see the B.A. Truck run, it will seem that the motor produces approx. 2000 HP yet at that level the lifespan of the motor/ transmission would be short. We are able to run as if we have 2000 HP available, while only 1600 HP is being applied to our chassis because of this “parts saving and friction fighting” technology! The end result is spectacular performance without the high cost of operation, or numerous breakdowns. To learn more about this, see the link to MicroBlue Racing. An illustration as to the effectiveness of this technology, is the fact that an average person can, with one finger, turn the rear-end yoke to propel the B.A. Truck. I have brought this subject to your attention only to share some of the latest high-tech info with you; perhaps it can solve some problems with your race car. Friction is no friend to a racer.
     Moving away from those esoteric subjects of physics, chemistry, and tribology, we shall now turn back to the simple iron and steel associated with the rear assembly.
The center section, casting and tubes, are from a Dana 70 HD rear that is rated to carry 14,000 lbs. If this seems odd to you don’t be surprised for I have never seen another housing like this one. It’s a very unusual piece from a 1968 Chevrolet 1½ ton straight truck. This center is very strong and allows us to choose from many different gear ratios and differential combinations. Our choice of gear ratio was 3.73:1 this low ratio helps to keep the radial torque to a minimum. Due to the diminutive size of the Dana 70 ring and pinion (10.5”), these pieces were put through the cryogenic process and then treated for friction reduction by the MicroBlue people.
     We chose to utilize a 4 spider open diff. which allows the use of individual brakes to guide the B.A. Truck when the front tires are off the ground. A technical note is required here; when one brake is applied, the diff. must slip while under power, this will cause a major loss of power to the wheels unless the diff. has been carefully treated to eliminate the internal friction. The B A Truck utilizes Torrington bearings and MicroBlue to address this problem. When a situation arises where the application of one brake is required to correct the course of the truck, the correction can be made without any noticeable change in the pitch of the motor!
     Speaking of brakes, most racers concern themselves with going fast yet the time to stop will arrive, sometimes quite unexpectedly, consequently brakes of a high caliber are necessary. Disc brakes were the natural choice. The 25” rotors are of our own construction, they are gripped by a pair of Audi calipers equipped with semi-metallic pads. Individual brake pedals, left and right, provide hydraulic pressure to effectively stop the truck.
     Axle shafts, connecting the open diff to the planet assemblies, are pieces made by Summers Brothers; these axles were made to our specs of 300M material and 1 1/2” in diameter with a 35 spline count. This may seem too lightweight for our application but the planet assy. greatly reduces the load on the axle shaft.
     Repeatedly I have mentioned the planets while neglecting to identify their origin. Sorry. The 11” diameter planets came from the front axle of an Allis-Chalmers farm tractor. Unfortunately no one makes an “adaptor kit” to combine these disparate pieces into a singular congruent unit, that task was tackled by us. “Some machine work necessary” became a commonly heard phrase, around the shop, for many months. The last parts to be manufactured were the wheel adaptors. Carved out of billet stock, their production, complete with simulated axle ends, signaled the conclusion of the rear-end assembly.
     The axle assembly was finished with a pair of steel wheels 18” wide x 15” diameter. The wheels commonly used by Modified pull- trucks are spun aluminum pieces manufactured by Real Wheel, when we contacted Real Wheel of Iowa, they informed us that their aluminum wheels would not hold up to the extreme stresses of a wheel- stander. We thank them for their candor and took their suggestion to contact Stockton Wheel of Stockton CA. Stockton Wheel supplied us with two steel wheels with ½” thick steel centers and the assurance that we would not break them. These wheels are enveloped by Cepek Giant Puller tires of 18.4 x 34 x15” size.
     Moving forward we come to the front axle, part Jeep Dana 30 and part International Harvester Dana 44. The basic axle housing is composed of two long side axle tubes (spliced together), with IH outer end assemblies. The basic housing is lightweight, while the outer ends are strong and durable. A pair of trailer springs and gas shocks provides the cushion between frame and axle for the front. This axle assembly was deftly installed, brackets and all, by Scott Laue from Expert Drive Line of Hortonville WI, we thank him for his assistance in this and other matters concerning the B A Truck. The front wheels (15”x5”) were donated from a Suzuki Samurai; they are lightweight, and strong enough for our application. Our very own Chrysler minivan provided the front tires that accompany these wheels.
Steering is provided by Mark Bendler at Kodiak Truck and Trailer, it is purely hydraulic in nature, and a hydraulic cylinder along with control valve (from a forklift) plus an electric over hydraulic pump provide all that is necessary to easily maneuver the B.A. Truck. Perhaps an explanation is necessary. A 12 volt electric motor turns a hydraulic pump, which pumps oil under pressure, to a control valve, through hoses, to the cylinder which turns the tires to allow maneuvering of the B A Truck. I was not familiar with this type of steering until Mark explained that monster trucks use this type of steering arrangement. He donated, built and installed the complete steering system.
     We have covered the rear and front of the B.A. Truck, but have neglected the middle, which is the transmission. The transmission is a production piece from Chrysler Corp. from a motor home. The trans has received a few upgrades because they were essential to the survival of the transmission assembly. The front planet assembly was replaced with a close-ratio assembly with billet steel housing to provide to necessary strength to withstand the torque of a supercharged motor. However the output shaft was a matter of concern to us, so we had it subjected to a cryogenic process (provided by M B R) to eliminate any residual stress within the shaft, thus allowing the greatest strength possible from its size/material configuration. The friction monster lives within transmissions also, necessitating the surface prep and coating with tungsten disulfide to all surfaces where there is motion, thus eliminating as much friction as possible. The entire trans case was deburred and radiused to eliminate the possibility of cracks starting. The direct clutch assembly was upgraded from four to six clutch plates in order to handle the torque requirements of this application. The friction discs in both clutch packs are Alto red discs, as they have proven their worth in applications such as off-road racing, monster truck racing, and truck pulling. The torque converter was hand-built for us by Marv Ripes at A-1 Automatic in California. If you have never had a custom converter made for you, the number of questions asked by the builder will make you think that he is a retired interrogator from the F B I. Every detail of the vehicle is taken into account. Things like weight, application, cam timing, lift at .050”, duration at .050”, lobe separation, every detail of the cylinder heads, intake manifold design, size of the blower, blower overdrive, gear ratio, tire size, and so much more. Such attention to detail is essential to vehicle performance and durability of the transmission assembly. This trans package is neatly wrapped in a thick blanket of ballistic nylon to contain any pieces in the event of a parts failure ending in the explosion of the transmission.
     We shall now examine the power plant; the legendary Chrysler Hemi engine. The engine block is a 1966 NASCAR piece, designed and produced for the rigors of racing, with extra material in the cylinder walls and main bearing areas. This block also is of a better alloy than its counterparts which were produced for street use. This block has been filled to give it greater rigidity while under load. If the block cannot hold its shape, while under load, many parts will fail such as head gaskets, pistons, rings, main and rod bearings, virtually everything attached to the block is at risk! Engine builders and block manufacturers have in recent years produced some very high-tech parts that accomplish this task, with much less weight than this vintage piece.
     A billet steel crankshaft with 4.5 inch stroke was chosen to be the base for our rotating assembly. Finding a good, used (affordable) crank was a major problem that was solved by Ray Drew, the owner of Starship Enterprise, a TA/FC Funny Car. Ray’s generosity, knowledge and spare parts solved this problem and others in our quest to have a complete blown Hemi motor. A longtime and close friend of mine Frank Vinze happens to be Crew Chief for this Funny Car thus affecting the connection. The load produced by the large blower belt (13 mm) and its associated stress necessitated the use of a billet crank. The crank was subjected to the full treatment, including cryogenics, by MBR in order to extract the greatest amount of strength and durability. While on this subject, the main, rod and cam bearings, pistons, rings, wrist pins, camshaft, magneto/ oil pump drive gear, pushrods and rocker arm assemblies were all surface finished and coated, complements of MicroBlue Racing. Durability is always a problem with high-output engines, we are thankful for the assistance. Most of the motor is standard fare for a blown- methanol Hemi. The pistons are pinned to aluminum connecting rods 7.2” and produce a compression ratio is 11 to 1, capped off with Indy aluminum cylinder heads, equipped with 2.40” intake and 1.94” exhaust valves, sealed to the block by soft copper .050 gaskets.
     Although the run time is short (only 2-5 minutes) per exhibition pass/ with warm-up, the need to provide cooling for the motor was obvious. Although the engine block is filled, the heads (where all of the heat is made) do have water passages to provide cooling. The area for the radiator was already occupied by an 11 gal fuel cell. What were we to do? A monster (truck) solution was offered by (Kodiak) Mark Bendler; use the left side frame rail as a radiator! The main rail is 2”x6”x16 ft long; this is plenty of capacity along with adequate surface area for cooling, a small electric water pump insures the circulation of coolant.
Howard at Childs and Albert’s helped us with the problem of sealing combustion gases to the top side of the pistons with ductile iron rings, and chrome high-tension oil rings to keep the oil in the crankcase.
     The roller camshaft is relatively mild, for the sake of valve train life, a steel billet ground to produce a lift of .729” and duration of 278 degrees at .050 lift with 114 degrees to separate the lobes. These specs are mild by all-out racing standards but we do not need 2200 HP or 2100 ft. lbs. of torque. To run a motor at these levels would shorten its life and accrue added expense.
     The intake manifold is magnesium in composition and low-profile in design, another vintage piece. The manifold is covered by a 1471 BDS supercharger with triple Teflon strips to insure sealing and efficiency. The blower is overdriven by 30% providing plenty of air, under pressure, to produce the torque necessary for wheel-stands. The blower (supercharger) was also put on a low friction diet by coating selected surfaces and the utilization of hand- fit ceramic bearings, all of which were specially prepared by MicroBlue Racing. We thank them for their excellent work. The polished Enderle top-hat is of early design (we prefer to say Classic design) in the “Bird-Catcher” size, distributing fuel supplied by a single Enderle 110 pump.
The air/fuel mixture is ignited by fire created within the Mallory magneto and sent through NGK spark plugs. This completes the engine package.
     The last part of the B.A. Truck to be examined is the portion which is most visible, the body. Looking at the original pictures will give you the impression of a relatively simple restoration. Just as in life, you always seem to get so much more than what is initially seen.
      This last statement is in reference to the rear doors which were solid, but badly beaten through the years. The restoration process, on these two pieces, would be long and arduous. Rick Krueziger, from Restoration by Rick of Lake Mills, WI, was contacted to tackle this enormous challenge. The donation of his time on these doors will be admired by many in the coming years.
     The rest of the basic body work was accomplished through the efforts of many. Andy Cartwright, Jason Buchholtz, Mark Bendler, B. J. Williams and I, Terry Cartwright, managed to construct a mockup of the truck, to precede the finished product for the 2006 season. The pictures on this website, prior to May of 2006, are photos of this pre-final product mockup.
     The final body/ paint product was left to the discretion of Tim Peterson, from Peterson Auto body of Waukesha, WI. His considerable years and talents in this business were to come into play on this project. The torque-twisting and vibration that the body is subjected to demands that the proper materials be used on the surface finish of the body. It was Tim who recommended the use of fiberglass fenders to save valuable time and to side-step the problem of cracking with the original steel parts. The numbers of details to be covered before the paint is applied are many, such as rebuilding every door hinge and rebuilding of the original latches, and reinforcement of critical body areas that are prone to cracking. Also finish details like window weather-stripping, fit / finish and trim for the windows. All of these consume time, talent and resources. Tim and the employees of Peterson Auto body Ray Wolfe, Fisher Love, and Fred Jahn donated their time and talent to produce the illustrious truck that you see.
     After all of this, the story is not yet finished for the stripping and lettering has not been mentioned. This final touch was much more difficult than I had expected for the size, color, tone, and style of every letter is critical to the finished product. The options for all of these choices are so numerous as to cause paralysis. Enter Mark Wenzel, Stretch by all who know him, owner of Signs and Lines by Stretch. His 25+ years of experience would be called upon for this important task.
     When a vehicle is detailed with colors that complement, curves that accent and style that matches the theme, a visual impression is made that instills awe in the onlooker. Should any of these things fall short, the package is flat and no permanent impression is made. At the time of this writing (Feb. 2006) many details of this topic are yet undecided. When you see the final photos, the details will have been decided.
     This completed truck meets or exceeds the safety requirements of Pullers Incorporated, NTPA, Badger Truck Pullers Association and every other truck/tractor pullers association that we are aware of. Safety for everyone involved is an issue that cannot be compromised.
The comprehensive management of this project was done by TNT Enterprises of Waukesha WI, Terry Cartwright proprietor.
     I hope that you have found the technical aspects of the B.A. Truck to be entertaining and informative, it has been my pleasure to share this info with you. We hope to see you at the track or at one of our display engagements.
Check out the Web links to learn more about those who gave of their time and resources to bring this memorable vehicle from the depths of degradation to renewed life for your pleasure.
                      Dr. Terry Cartwright