Tractor Pulling - A Bad Little Tractor

Paul Barnsley of Frederick, MD makes a pull with his turbocharged 1952 Allis Chalmers CA, "Clockwork Orange"

     Turbocharged. It's a word that conjures up images of large, powerful machines: fighter jets, race cars, big semis. But to Paul Barnsley, a 42 year-old Marylander, it inspired a challenge with a twist: he decided to put a turbo onto his 1952 Allis Chalmers CA pulling tractor, which he dubbed "Clockwork Orange."

     Paul is a tractor and snowmobile mechanic who also grows hay and field crops. The idea for turbocharging a small tractor came about when he attended an antique tractor pull at Aquasco, MD. It was there that he saw a John Deere 70 Diesel which had been nicknamed "Hazardous Material." Bill Grimes of Davidsonville had fitted it with a turbo and entered it in the open class. At it wound up and headed down the track, the tractor let loose a plume of black smoke and emitted a unique, almost unearthly howl that signaled a two-cylinder John Deere making 40 lb. of boost and hauling the sled faster than anyone ever imagined an antique tractor could go.

     "It was exciting," Paul recalls. "I said to myself, 'I can do that!'"

     He came to the task well-armed with knowledge born of personal experience. Paul had started antique tractor pulling in 1970 with a 1953 Farmall Super H in stock classes. Within a few years, he and his brother Ivan had made the transition to Super Stock and Modified pulling tractors. His most notable success came with "Tumbleweed," built on a John Deere 540 log skidder rear end, that machine featured two 440 Dodge motors with Hilborne injection and 671 Detroit blowers. By the early 1980's, Paul had cracked the Top Ten ranks of the National Tractor Pulling Association for Region I.

     It was a watershed time for Paul. "People with lots of money were getting into the sport," he notes with chagrin. "They were willing to spend whatever it took to win. I loved running Modifieds, but it got too darn expensive for just regular working folks like us." The prize-winning "Tumbleweed," now troubled by the vagaries of time and hard use that called for costly repairs to keep it running competitively, came off the track. Paul returned to antique stock tractor pulling, this time with an Allis Chalmers CA.

     He did well with the CA but Paul was not one that was accustomed to being content with staying with the same-old same-old; after a time, he wanted to try something new and different. Then he saw "Hazardous Material," and a dream was hatched.

     A factory issue CA came with a 125 cu. in. engine rated at 23 HP. Paul switched to an Allis Chalmers D-10 Series III motor. He installed an overbore sleeve kit with 3 9/16" high-compression pistons. The crankshaft was prepared as for a standard engine but with better bearings.

     The turbo he used had started life in a Subaru car. In order to mount the turbo correctly, Paul fabricated the manifold himself. In a testament to the deliberate and meticulous work that he does, it should be noted that when he took this handsome manifold to the machinist's shop for planing, it required only 0.020 to true it up.

     The hunt for a satisfactory carburetor led to an experiment. The first attempt involved a Mikuni snowmobile carburetor, which controls airflow with a slide shutter. But the turbo rushed air so furiously through the Mikuni that, even in summer, the carburetor housing frosted and froze the shutter in the wide open position.

     Better luck ensued when Paul chose the carb off a Ford 3000 gasoline tractor. This updraft Holley performed well. As might be expected in a high-performance set-up, it required 110 octane gasoline, such as CAM-2 or Turbo Blue. An electric fuel pump, controlled by a toggle mounted on the driver's right-hand side, was added for enhanced fuel delivery.

     The oiling system was the most exotic piece of engineering. The factory oil pump on a CA was minimal. It was replaced by a power steering pump from a D-10/12. He lowered the relief valve pressure to 35-40 lb. and added a full-flow oil filter. Greater oil capacity was needed to serve the turbo and higher speed engine; thus, Paul remade the oil pan to increase its depth, raising its capacity to three gallons as compared to the one gallon held in a standard pan. He ran with 15W40 Marine Diesel Amsoil.

     The need for speed and power dictated that modifications to the head be devised. The head was ported and polished; big valves were installed, along with heavy duty valve springs.

     Early runs demonstrated that heating of the turbo during high RPM pulls could be a problem, especially given the ambient 90 degree heat of Maryland summers at the height of the tractor pulling season. Paul designed a cooling system whereby a water tank was mounted on the weight bracket in front of the radiator; using a 12V pump normally used in recreational vehicles, he could pump ice water through the turbo inner jacket. Problem solved.

     A hard-running, high powered motor was bound to be too much for a standard drive train. A custom-made cerametallic clutch built to Paul's specifications proved tough enough to take whatever the engine could dish out. The rear was outfitted with cut and sharpened 14.9 x 28 tires, with 4.00-12 tires up front. Running high in back and low in front, "Clockwork Orange" cut an aggressive, feisty profile that seemed to challenge out loud: "Catch me if you can!"

     A local antique tractor pulling club was chilly to the idea of trying an open class for a tractor of the CA's size, and would not even consider an exhibition. "I think the idea of a hot little tractor scared them," chuckles Paul. Happily, a more open-minded group of antique tractor pullers was to be found in Southern Maryland, where the notion of screaming RPMs caused more thrill than apoplexy.

     Safety equipment was mandatory when pulling with such altered horsepower. Wheelie bars were made in Paul's shop, as were aluminum side panels that were placed on either side of the engine. A scatter blanket was wrapped around the clutch. Finally, kill switches were mounted in two places: one under the driver's seat (attached to the sled with a piece of cord in order to force a halt if the sled and tractor disconnected during a pull) and one mounted on the throttle lever, quickly accessible to the driver's fingertips.

     The most difficult part of the project stemmed from Paul's resolve to make all the special engineering fit neatly into the engine compartment so that the standard sheet metal would fit over it just like a factory motor.

     "I'd seen guys slap an engine together, and when it came time to put on the tin, they just hogged holes and gouges into it to make it fit," he frowns. "It looked awful. I made up my mind that I wasn't going to do that." True to his word, Paul spent much time fitting the turbo, manifold, and other components carefully so that when it came time to put the hood back on, all that was necessary for a good cosmetic fit was to use small adapter plates to raise the hood an inch higher than it normally would have been.      Stripped down without PTO, hydraulics, or water in the tires, the CA weighed 2350 lb. including safety equipment. Paul has run it in classes ranging from 2500 to 4000 lb., utilizing weight brackets in the front, mid-mount, and rear to reach the heavier classes. Its performance has always been creditable; in the 2500 lb. class, where it performs to its best ability, it never fails to impress with a showy pull and excellent distance. It has never had a mechanical failure, and boasts a turbo boost of 7 lb. at 3500 RPM. Dynamometer testing revealed that when pulled down to stock RPMs (1650), this bad little tractor made 60 HP!

     One might think that such a high-performance, finely-tuned machine was only good for tractor pulling competitions. But at a rainy pull in Richmond, VA, Paul found that his pickup and gooseneck trailer were mired in mud. He unloaded the turbo CA and it handily extracted the whole rig, pickup and trailer still loaded with an Allis Chalmers WC and an Allis RC! It's said that the sight of Paul and "Clockwork Orange" entertained more people than anything seen on the track that day.

     Turbos: they're not just for big things anymore.