With a new S233 in the yard I wondered how it would fare against its great, great grandfather, Brian’s BM320. Having downloaded the original sales leaflet I’ve made a few comparisons to see how much things have changed since the early 1960’s.
There’s the obvious one, weight. The S Series does look like it could be a gram or two heavier. Actually at 12000Kg it is about 8 times heavier than the 1570Kg of the BM320 although surprisingly it only has 52mm more ground clearance.
It can carry a bit more fuel too. You can get 35 litres into the 10th model Bolinder Munktell produced. The S takes a bit more fuelling up with its 60 litre AdBlue & 610 litre fuel tank.
The BM’s three-cylinder 2.5L Perkins turbulence chamber engine could produce a maximum of 37hp at 200rpm compared to the 270hp produced by the 8.4L, 6 cylinder, Sisu Power engine.
The continuously running, two-speed power take-off introduced with the BM320 was really intended to compensate for shortcomings in the gearbox and gear ratios, but it became something of a sales success for Bolinder Munktell, doubling the range of machines it could power. Valtra’s electro-hydraulic PTO now has start/stop control inside the cab, on the armrest & outside, on the rear mudguard & has a fuel economy setting.
As you would imagine the S Series can lift a bit more. In the 1960’s you had a respectable maximum lift capacity of 1050Kg. Now you can lift nearly 5 times that on the front linkage (5000Kg) & more than 11 times that at the back (12000Kg).
The roots of Bolinder Munktell & Valtra go back to a mechanical workshop in Sweeden “Eskilstuna Mekaniska Werkstad” founded by Theofron Munktell in 1832. Several mergers later, including Volvo & Valmet they ended up as Valtra where it remains today.