Tractor pulling in America means a lot of things to different people. Many in the general public regard the sport as nothing more than stock trucks and tractors coming in off the farm and doing their thing at the county fair.
That was then, this is now. The sport has grown from those humble roots to tractors with a varied collection of powertrains and numerous engine types. In certain classes, more than one engine is allowed on a single pulling vehicle. The technology is amazing, touching the levels of national drag and stock car racing.
It’s an engine builder’s dream where the rules allow modifications in all classes to varying degrees. Some classes use mostly “bought” engines, others see teams buying the parts and pieces from professional engine builders and assembling the engines themselves. And finally there are those who buy a partially assembled, company built engine and finish it off to their liking. It’s long been the situation that most of the engines are home-built.
It’s amazing how some of these engine builders demonstrate amazing technology with their builds. For many, the creativitiy of one-off pulling engines is a necessity, as the cost of a turn-key engine would keep them from competing in the sport.
This article will attempt to closely examine the engines that perform the amazing feats of pulling power, made harder by the fact that in all cases the weight to be pulled is sitting at a dead stop. There is incredible power and torque required to get those thousands of pounds moving in the first place. But they make the task even more challenging because the sled is getting heavier with every foot it moves down the track. Obviously, it is imperative to quickly acquire maximum momentum. Near the end of the pull, when the engine/engines are striving for that final inch or two, the strain on the engine is stretched to the max.
One of the sport’s most recognized members, Gregg Randall, general manager with the National Tractor Pulling Association (NTPA) was a valuable contributor to this article. NTPA is not the only pulling organization in the USA or certainly other countries. But its rules are very similar to the other groups allowing pullers to often compete with multiple pulling organizations.
NTPA Tractor Classes
The NTPA is at the top level of pulling and was formed in 1969. Over the years, it has sanctioned pulls in many eastern states. It has both National and Regional Divisions with similar classes competing in both venues.
The so-called Stock Class includes tractors, which are stock-appearing and all use diesel fuels except for the Super Stock Open class, which is allowed to use methanol. The attraction here is the columns of smoke that are generated by the swirling turbochargers as they wind up to full power with diesel fuel.
The ‘Stock’ name is important to the class since all the tractors must use factory sheet metal externally. Check any NTPA pull and you will note that the John Deere and International tractors are favorites. Randall explained that having that stock appearance brand brings great fan recognition, like something they would drive on the farm.
Probably the biggest difference from other motorsports is the multiple engine configurations of the Modified Class. This class started out with single engine configurations, but found that more power could efficiently be made with the use of multiple blown alcohol engines joined precisely together. Through the years, the tractors have seen three, four, five and more engines. The complexity of joining these massive engines boggles the mind, and also the pocketbook. The sound and sight of many of these tractors with fire-breathing big blocks and thousands of horsepower clawing for grip is a great fan favorite.
Stock Pulling Tractors
The engines used in these classes are mostly modified versions of John Deere and International diesel engines.
The thrifty Super Farm class is very popular in Regional NTPA competition. It starts off with a 640 cubic inch and is limited to use of a single 3×3 inch turbocharger. The top vehicle weight allowed is 9,300 pounds. A ‘P’ pump and water injection is allowed, but there are no intercoolers or overhead cams allowed. Horsepower is in the 1,300 range.
There are three Pro Stock classes, which include Pro Stock, Light Pro Stock and Limited Pro Stock. Pro Stock tractors weigh 10,000 pounds with a 680cid engine with a single turbo. Water injection is allowed. Limited Pro Stock is a restricted class. There must be OEM heads with no overhead cam and only two valves per cylinder with a 4.1-inch turbo. According to the pullers, the Light PS Class is gaining popularity with its 540cid engine and 8,500 pound vehicle weight.
Super Stock tractors can be fueled with either diesel or alcohol, depending on the class, and use multiple turbos. Heavy Super Stock tractors at the Regional level must weigh 8,000 pounds for diesel and 8,300 for alcohol. There are also different vehicle weight rules for modified and stock tractors in the Light SS Class, which weighs 6,000 pounds and Grand National Open SS tractors also have an 8,000 pound weight limit.
Professional Stock Tractor Engine Builders
Gene’s Machine Shop (GMS) builds turn-key engines for Unlimited Super Stock tractors, about 20 of them every year. It is also involved with injection pumps and turbochargers and has CNC porting capability in-house. Co-Owner Brent Payne explained, “Probably 50 percent of GMS customers buy GMS parts and assemble the engines themselves.”
Riverside Engines, based in Tiffin, OH, produces stock engines for a number of classes. Included are 680/3,000hp Pro Stock engines, 640/1,500hp Super Farm engines, and four-turbo Super Stock 540 engines capable of 3,000+ horsepower. In addition, there are also engines for the LM Pro and Lite Pro Classes with a 4.1 turbo and a P pump, respectively.
There are a number of organizations that perform a number of functions including testing and fabrication of certain engine functions.
Crower Cams’ Kerry Novak explained that the company’s concentration is on diesel engine components (cams, cranks, rods, lifters, etc.). He added, “We work one-on-one with the customer. We try to satisfy their needs like more torque, higher rpms, or a smoother running engine. Also, we will fabricate custom parts. I am encouraged with the health of the sport. It’s sure doing better than oval track racing.”
Columbus Diesel’s phone number is on many diesel tractor owners’ phones. The company provides a montage of important pieces including turbos and fuel systems. The company also supports the Stock pullers on site at the pulls. The working goal of the company is to achieve more power and have less breakage.
Engler Machine and Tool is unique in that it supports both the diesel and alcohol classes with the diesel engines getting attention with its production of fuel nozzles, turbocharger plumbing and water nozzles.
HYPERMAX Engineering’s resume is strictly the Stock diesel pulling tractors. Owner Jerry Lagod explained, “A majority of the support goes to some two dozen Stock teams, mostly the IH tractors. We also build three to four complete engines every year. We do a lot of R&D in-house and have an impressive CNC and dyno capability. We also manufacture fuel injection pumps, turbochargers, along with injection nozzles and lines. From where I stand, the pulling sport is showing a gradual growth.”
Nyes Automotive is located in Muncie, IN and its forte is machine work supporting diesel engine repair, porting and polishing. Much of the work is involved with the Super Farm and Light Pro Stock classes.
Salenbien Performance provides a warehouse of parts to support the stock engine tractors. The selection includes turbocharger parts, injectors, pumps, rocker arms, rods, deck plates, air velocity stacks and lines. The company is also an expert on diesel engine dyno evaluations and tuning.
Simpson Performance is run by longtime diesel performance guru, Mac Simpson, who has been involved since 1975. He’s well known for his water injection systems for the diesels and many are out there. He also fabricates turbochargers. He says, “I am very worried about the heath of the sport because of the growing costs of the equipment.”
Wipe-Out Enterprises does a small amount of engine building (about 10 per year) but its greatest engine interest is in fabricating parts and looking for horsepower in the Super Stock Class. Testing is a big portion of its Stock Engine activity.
Home-Built Stock Engine Building Examples
The Super Farm ‘Thunder Struck’ engine of Brad Woods started out with a 619 cubic inch from an 8760 John Deere tractor. There are many aftermarket parts including 14mm Harts fuel injection. “I used a lot of parts from Riverside Engines. It’s pretty competitive and makes about 1,400 horsepower.” A nice piece of work for a home-built powerplant.
The homemade engine of James Vanhoy’s Light Pro Stock started out as an 8.1L version from a John Deere 4450. “The engine was making about 130 horsepower when I got it, now it gets about 2,100hp! I was able to get the additional displacement to 540cid with bigger pistons and liners. It now carries a single turbocharger from Columbus Diesel, which provides about 110 pounds of boost. I bought a lot of the aftermarket parts from Riverside and put it together myself. Figure it saved me about 20 percent over buying a new turn-key engine.”
Rich Lustik showed that building it yourself can really pay off since he is a 10-time World Champion in the Super Stock Class. He had the first four-turbo engine in 1979. His current tractor, the “Silver Bullet’ uses 3208 CAT/3 turbos on alcohol. ν
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