Bob Stewart's 880 2-row New Holland corn chopper requires at least 130 hp. To use his 90-hp Deere 4010 tractor to power it, he had to find a way to provide additional power. His solution was to mount an engine directly on the chopper chassis itself to provide a boost to the powering tractor pto.
The dual-drive combination of the 90-hp tractor and the add-on International 6-cyl. 80 hp engine provides plenty of power to operate at full capacity.
"Both the tractor pto and engine run at 1,000 rpm's. Almost all parts were salvaged from equipment I had around the place," says Stewart, of Zillah, Wash.
Figuring out how to channel power from the add-on engine to the powering pto shaft was the most difficult part of the conversion. A pulley off the rear-end of the engine belt-drives a drive-shaft that direct drives a pulley on the pto shaft, mounted directly behind a "slip dog" freewheeling cog joint which is key to the success of the conversion. The "slip dog" joint lets Stewart shut the pto off but leave the chopper engine running. When he turns the pto on, the cogs automatically engage.
The add-on engine is remote controlled from the tractor so at end rows Stewart shuts down the pto and throttles down the engine. Once in the field, he runs the engine at full throttle.