Chopping silage (or any forage) is all about power; simply put, the faster you want to go, the bigger the engine you need.

It is this straightforward equation that has driven the development of self-propelled forage harvesters over the years – to the detriment of their trailed counterparts.

Indeed, manufacturers of tractor-drawn forage harvesters faced a dilemma in the 1970s and 1980s, as the farming world embraced self-propelled units (offered by the big-scale manufacturers).

This cut the market from under their feet. One retort was for these companies to produce their own machines. This was a route taken by Mengele of southern Germany.

The company produced a variety of self-propelled harvesters over the years, including the SF300 (perhaps more aptly described as a self-propelled ‘power unit’ to which a forager can be mated). It harks back to the 1980s.

It was certainly at the smaller end of the market; it churned out just 150hp (at a time when 300-400hp self-propelled foragers were available).

However, the SF300 did have the apparent advantage of being cheaper to produce – precisely because it wasn’t a fully integrated forager “from the ground up”.

The Mengele SF300 was typically mated with the company’s SH40N (in ‘reverse drive’ configuration). Muscle was supplied by a six-cylinder, air-cooled Deutz diesel engine, located at the rear of the machine.

It delivered its output to both the transmission and the forage harvester via a series of belts and shafts. It was not an especially sophisticated arrangement, but it worked well.

This particular machine’s latest owner, Jimmy O’Driscoll (pictured below on the left with his son PJ on the right) of Pedlars Cross, Co. Cork, explained: “It could deal with lumpy swaths far better than a 150hp tractor and trailed harvester.”

That might be due to a power-train that doesn’t appear to sap too much power.

Jimmy purchased the machine in March of this year with the express intention of having it running in time for the Ahiohill Vintage Rally, which was held at the end of July.

This proved quite a task. Not only had it been stood in a shed for a decade; it had also been partially dismantled. Some components had been removed.

The job took exactly “five months and two weeks”. Although the machine is now fully functional again, it is not quite finished yet.

Jimmy will not take full credit though. His son – PJ – was very much involved; he did a great deal of the work under his father’s watchful eye.

As a training ground for an aspiring engineer, this project would be hard to beat. PJ is now as much of an expert on the machine as his father.

One of the major components that had gone missing was the linkage assembly, which joined the harvester to the ‘power unit’.

Unfortunately, they didn’t have access to another one, so a new unit was fabricated – with the aid of “one photograph and a lot of guesswork”. Whether it conforms exactly to the original is unknown. However, it does work.

Other problems included some rather tired electrical cables and connectors. Although not fully rewired, any suspect parts of the loom were replaced.

The turbocharger was seized solid; it required a good deal of attention, along with new bearings, to get moving again. The rest of the engine was running “as new” – so was left as was (except for the usual service items).

In a bid to use readily available components, Mengele had turned to the world of combine harvesters to source some of the running gear – the Claas Senator 80 in this particular case.

The axles, gearbox, variable-drive unit and all belts were borrowed from that model; it means that parts can be located.

Sourcing parts

However, Claas parts don’t always come cheap; Jimmy was quoted €1,200 for the main drive-belt (if such a part were to be supplied through the “official system”). Having (metaphorically) picked himself up from the floor, he settled for an alternative elsewhere – for just €400.

Having brought it back to “running condition”, Jimmy has every intention of taking it to shows. Indeed, it was his desire to help raise money for charity that motivated his decision to buy and restore it.

It turns out that this example was first sold by Murphy Machinery (Kilkenny) to a local contractor. How long that contractor had it is not known.

It was then sold to another farm (elsewhere in Co. Kilkenny), where it is believed to have cut 600ac each year for a suckler herd (before being retied to a shed). It was here that Jimmy found it – rescuing it from a slow decay.

Thankfully, any rust is still superficial and this winter’s job will entail a full re-spray. That’s not a prospect for the faint-hearted!

However, both the father and son are not at all fazed by the idea. In fact, they can’t wait to see it when it’s fully finished.