1985 BIG BUD 650/50
THE BIGGEST BIG BUDS & THE WORLD’S BIGGEST PLOW
On August 28, 2018, giants walked the earth at Alvordton, Ohio. On that day, the second biggest Big Bud tractor model, the 12V-92 Detroitpowered 650/50, and the next biggest, a Big Bud 525/50 (see Diesel World January 2018 or go to Dieselworldmag.com), plowed side by side at the Alvordton Plow Days. That was momentous enough, but the 650/50 plowed with the biggest moldboard plow ever made, the 21-bottom DMI plow, built in 1978 to be a show stopper.
The Alvordton-mill Creek Volunteer Fire Department has been putting on the Plow Days since 2009 as a fundraising function. It’s been growing bigger every year, and 2018 put it into the world-class category. In conjunction with Kunkle Farms and Meyer Farms, the Alvordton event is open to tractors about 40 years old. Obviously, that rule was waived in light of the significance of the Big Buds. Depending on Kunkle’s crop rotation, there can be as many as 150 acres of wheat stubble to plow. The real danger this
year was preventing the two monster plows from working up all the ground before the little guys could dip their plowshares.
Back in the January 2018 issue we talked about how the Big Bud tractors came to be. Built in Havre, Montana, they dominated the high-powered tractor market in the late ’70s and early ’80s, if not in volume then by size and power. The 1978 Big Bud 16V-747 was the biggest of those, powered by a massive 16V-92T Detroit rated at 760 horsepower. That was insane horsepower in that era, and while Big Bud was willing to build more of them, only one like it was produced. It remains the biggest ag tractor ever built.
The Series 3 tractors debuted shortly after the 16V-747 and the top dogs among them were the 650/50 and the 665. Both were powered by Detroit 12V-92T V12 diesels. The 650/50 was rated for 650 maximum flywheel horsepower, while the 665 made 665. The significant difference between them was in the chassis, with the 665 having a heavier nose and weighing about 1,000 pounds more. Only two of the 650/50s were configured for agricultural use, the others being set up for construction work. Only six 650/50s, two 665s, and one 650/84 were built. Why so few?
The Series 3 tractors were introduced with a beefy new Twin Disc transmission. Regrettably, those transmissions had teething issues and began dropping like flies. None of the Twin Disc updates fixed them. Twin Disc faced a massive problem, but Big Bud was in worse shape, having built a bunch of pre-sold tractors that sat there waiting for a working transmission—with no fix in sight. This ended up sending Big Bud into Chapter 11 and stopping production. As a result, just that handful of V12 tractors was built.
The day before the August 28 Plow Day, Larry Addleman and Daren Meyers got together for some test-and-tune field work with the two Big Buds. Addleman’s more powerful 650/50 was elected to pull the 21-24 DMI plow, while Meyers’ 1980 525/50 took on the
Got 12 cylinders, uses ’em all! The dual stacks tell you this is a vee-type engine, but you don’t see many V12 tractors out there. The Big Bud 650/50 shown here belongs to Larry Addleman and it’s currently the only one of the two ag units still in the States, the other having been exported to Australia years ago. Addleman bought the tractor from Ron Harmon at Big Equipment 16 years ago. Harmon is the guy who put Big Bud on the map, and when it failed in the midst of the Twin-disc fiasco, he created Big Equipment to support the 518 Big Buds that were built. This one had been used in Colorado, then sold it back to Harmon. Harmon refurbished it and sold to Addleman, who uses it on his large Southern Michigan farm. Addleman is a well-known Big Budd collector, with five in his stable. Besides the 650/50 he has a 525/50, 400/30, 400/20, and a 450, which is the last Big Bud tractor ever built.
The 12V-92 was factory rated between 625 and 700 horsepower at 2,100 rpm, and with injector changes this one is now at the top 700 rating. There’s more available, but how much more can you use? This four-valves-per-cylinder monster weighs in at nearly 4,300 pounds, outweighing most automobiles and some light trucks. With 1,104 cubic inches, the turbo-intercooled 92 Series was introduced in 1974 with improvements over the venerable 71 Series. That included a bore increase from 4.25 to 4.84 inches, but retaining the original 5-inch stroke. Your initial thought might be that the engine is configured like two inline sixes joined at the crankcase, and that’s the way the earlier 12V-71s were built. On the 12V-92, it’s two 6V-92 blocks bolted together, and they use four 6V-92 heads. This saves a lot of manufacturing complexity, as well as repair costs down the road. These engines also used two 6V blowers to supply the atmospheric airflow, and the turbos, fed from two 6V manifolds on each side, push even more air in. By the time these engines came out, two-strokes were on the decline and they aren’t as common as they might have been in another era.
Addleman’s ’85 650/50 spent the first half of its life on a huge wheat farm in Colorado. Originally rated at 650 horsepower at the flywheel, when he had it overhauled in the early 2000s Addleman installed a few upgrades that boosted it to 700 ponies. The tractor mounts four 900/60-32 radial tires and puts a lot of rubber to the ground. Most, but not all, Series 3 Big Buds mounted what was called the “Cruiser” cab, built by Custom Products of Litchfield, which were an improvement on the previous cab. According to most sources, the yellow striping only appeared on the two 650/50 ag tractors. This tractor is currently showing just under 6,400 hours.
The 21-bottom DMI is adjustable, so the plow spacing can be between 12 and 23.5 inches—actually a bit more than the indicator will show. You could use this capability to suit field sizes, but it’s mostly to control draft. If the ground was tough and the tractor was having trouble, you could narrow the spacing to ease the load. This plow was built to promote DMI at the 1978 Farm Progress show at Taylorville, Illinois, where it was pulled by a Stieger Tiger. Originally rated at 450 horsepower, the Tiger had no hope of pulling it until the Cummins KTA 1150 was pumped up to 600 horsepower and its four 30.5-32 tires were filled with liquid ballast. Even then, the mighty Tiger struggled and the powertrain screamed in agony. Bill Dietrich thought the Big Bud 650/50 was a good match for the 21-bottom plow.
The inside of the Cruiser Cab is a nice place to work. Heat, AC, suspended seat, good soundproofing, great visibility, tilt steering, good control layout, and even a reasonably comfortable jump seat for company.