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JBS Racing Camshaft  - The head on the Husaberg is a generic casting that is used for all the capacity engines that Husaberg make or have made. These range from a 380cc up to a 644cc the head is really struggling to supply enough fuel / air mixture to the combustion chamber once you take the engine beyond “650”. This leads to engines that have a lot of power at the bottom of the rev-range but no more or even less than stock at the top depending on how big you take the capacity. The engine feels a bit like a tractor.

The solution to the problem ultimately is to make a bigger head casting with bigger valves and bigger gas passages. This is not economical for the Husaberg at present (we have looked into it) so the next best thing that we can do is to look at the camshaft.

It is normally difficult to increase the lift and duration of a camshaft without having adverse affects on the life of the valve train. However the Husaberg camshaft uses cams with a large negative radius / hollow flanks. This is so that they can achieve a relatively high-lift with a short duration. This design has the very undesirable effect of producing very high peak accelerations (twice what is considered “normal” from a design point of view). So it was possible by careful design to make a camshaft that gives both an increase in lift and duration but at the same time reduces valve train forces so promoting better life.

As we had decided to take the plunge and have a batch of camshafts made we also decided that we would try out an idea we had for an adjustable camshaft. So the design below was produced by our machinshop. This design allows interchangeable lobes to be put on the camshaft. Replacement lobes and even custom lobes for a specific engine application are cheap as the main part of the camshaft is retained in each case.

Using this camshaft fitted with an appropriate profile for the capacity that is being run all JBS Racing engine configurations can be optimised for smooth power all through the rev-range including the top-end. This camshaft will also fit KTM with a small modification contact us about it.

This entry was posted on Wednesday, April 30th, 2008 at 10:17 pm and is filed under Engine Develoment. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.