Few reserves, no constant power and high fuel consumption – the Valmet 8100 engine did not do well in a comparative test carried out in 1994. Valmet (now under the Sisu label) has quickly responded to this feedback and has come up with the recently introduced 8150 model. In this report we find out how the new 92kW/125hp engine performed in the field and on the test bench. Text by Manfred Neunaber, photos by Stefan Tovornik
Despite the other ratings in the comparative test against nine other tractors in the 120hp range the poor marks awarded to the Valmet 8100’s engine was a clear verdict. Valmet responded immediately and launched the Valmet 8150 at the end of 1995. This model replaces the 8100. The engine’s rated output has been increased by 4kW.
A quick response to user feedback is good as long as the replacement is clearly better than the one that was criticised. So, when we tested the tractor, we concentrated on the engine. Does the engine’s new fuel injection pump together with the new “Permatorque” engine characteristics really bring the needed improvements?
Our test carried out at the DLG test station produced some quite good results. Maximum pto output at rated engine speed of 2,200rpm was 81.5kW. But the Valmet 8150 engine was capable of more than that. As engine speed dropped, output under load increased to a maximum and comfortable 84.5kW (at 1,750rpm engine speed). It only fell below the result recorded at rated speed when engine speed fell to less than 1,750rpm.
In practice this means that output remains constant through a speed range that is as high as 20% (of rated speed). The Valmet 8150 even delivers an extra 3kW of power. Torque increases by a comfortable 39% until engine speed has fallen to 1,300rpm. Starting torque is very good at 134% (of the torque at rated speed).
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