You’d be forgiven if you think that Cummins swaps are something new and confined to the light truck realm. Not so, diesel heads, and here are a couple of tractors to prove it.
In the 1950s, the era of the diesel tractor was just beginning. Diesel-powered tractors were just a tiny part of a market dominated by gasoline. It might even be safe to say that the propane-powered tractor market share was almost as big as diesels. That was soon to change, but if you were a farmer sold on diesel power in those days, you had slim pickings. Why? Partly, it was the diesel technology of the time, which had only recently evolved into a size practical for tractors with a power output and rpm range that approached gas engine levels. Many farmers were hesitant to jump on the bandwagon and, frankly, the infrastructure wasn’t fully in place to support a large number of diesel tractors on farms.
On the other side of the manufacturing coin were independent diesel engine builders who promoted the use of modern high-speed diesel engines… their engines, of course… and were looking to place them into as many parts of the motor industry as possible. Among the heavy hitters in this were General Motors and Cummins, who actively pursued tractor diesel conversions.
According to Galen Wilkinson and Louis Wehrman, the owners of the tractors you see here, Cummins invited 28 Indiana farmers to their Indianapolis facility in 1958. The purpose was to float the idea of repowering International Harvester tractors with Cummins engines. Yes, IH was making diesels in those days, but they were anemic things compared to what Cummins was offering.
Gumz farms of North Judson, Indiana, saw the benefits of Cummins-powered IH tractors and stepped up. They ordered two Farmall 450 tractors without engines, one narrow and one wide front. There’s evidence that IH was at least an interested party in this deal, but it isn’t clear how much they were involved. It’s very likely they were “interested” on some level, but little paperwork exists to show the degree of interest. IH was using Cummins J-series six-cylinders in some of their OTR semi-trucks, so the two companies had a little history at least. We also know IH was well on its way to becoming a powerhouse diesel engine manufacturer then and too much business between them would soon have led to market conflicts.
The two Farmall 450 tractors were received by Gumz in December of 1958 and two J4-70 engines from Cummins arrived in March of 1959. The engines and tractors came together shortly thereafter when the engines were installed at Gumz Farms under Cummins supervision. Gumz was, and still is, a major multi-state farming entity, with Indiana being where this German emigrant family first settled in the early 1900s. Gumz used the converted tractors for 10 years before selling them off separately. With new owners, they continued to be viable as farming implements into the 1990s when they began to acquire some collector interest.
Let’s not forget the tractors in all our Cummins excitement. Both the Farmall 450s were standard units, save the few mods necessary to fit the engines. The 450 had debuted in 1956 as an upgrade to the 400 model. The upgrade was mainly an increase in engine displacement. The 450 was at the end of its run in ’58, when Gumz purchased the two without engines. The restyled 460 model would replace it in late ’58. The 460 and its bigger brother, the 560, would be plagued by final drive issues due to their increased power levels being applied to a warmed-over, old generation final drive. Reputedly, the two converted 450s suffered from a touch of this in later years.
While Cummins was actively pursuing the use of their engines in agriculture, this was a marginal market for them until the late ’70s when they collaborated with Case to form the Consolidated Diesel Corporation. The fruits of this collaboration, among other things, would be the B, C and ISL series engines branded both by Cummins and Case. All of those engines would find extensive use in the ag world. Yeah, Cummins conversions are now all the rage, but now you know the rest of the story. DW