Heinz Müller has travelled to many parts of the world for MANN+HUMMEL. In this blog post he describes how snowfall during an engine test in Sweden led to an innovative idea – another exciting story of Heinz Müller’s experiences in the field:
“In the winter of 1984, I travelled to Lapland for an engine test with an important client. I was responsible for the air filter. During our two-week stay, we experienced average temperatures of -23°C and continuous snowfall.
Although this should have been disastrous for us, it ultimately prompted us to develop our first anti-snow system.
The problem with the engine test performance
Once we had fitted the measuring instruments in the diesel vehicle, we got started. However, the test had scarcely begun when the first problem arose: The engine performance dropped significantly and the car no longer accelerated properly. We moved the vehicle to the workshop so we could get to the bottom of things, but found nothing out of the ordinary with the engine. So we drove the test line again. The engine performance was even worse during the second attempt. So back to the workshop we went…
When we opened the air filter cartridge, the problem became immediately apparent. It was completely frozen due to the extremely fine snow which must have entered the filter during the drive. While the car was in the workshop, the snow in the filter had thawed slightly. The second drive outside had caused the melted water to freeze into ice, which explains why the engine performance deteriorated even further.
Hectic weeks for the filter developer
To add to this already tense situation, the test managers, including the assembly development manager, had arrived. It was clear to the manager that I, as filter developer, was responsible, and had to resolve the problem. Three hectic weeks of innovation and prototyping followed.
My idea for optimizing the system was to catch the fine snow using a filter attachment. This type of fitting causes power to drop by around two to three HP. However, that doesn’t matter on snowy and icy roads as you can’t drive full speed anyway.
Timber transporters to the rescue
Tests on the new system were due to take place in Östersund. But how could we test a filter which was supposed to catch snow when it wasn’t snowing? We tried everything, even strapping a fir tree to the back of a vehicle to stir up the snow. In the end the solution was a lot closer at hand: countless timber transporters shoot up snow particles when they drive on the snowy Swedish roads; we just had to drive behind them.
The result of all our efforts was an extremely fine mesh (0.2 millimetres). In the future, filters would also be mounted in a vertical position and fitted with a water drain designed to prevent water accumulation in the filter housing base, thus avoiding ‘hydraulic shocks’.
It may have been out of necessity that we developed the first anti-snow system in 1984, but this system was subsequently used for many years. We were proud of what we achieved. From our perspective as suppliers, it also had another happy and important outcome: the assembly development managers were happy!”