As you will no doubt be aware, the committee have for some time been investigating engine availability and to this end we have been working extremely hard, dyno testing a range of possible options.
To date we have tested Honda GX340, GXV340 and GXV390; Kohler Command Pro CS; Loncin 452cc vertical; and the Tecumseh vertical.
As a result of this work, it has been decided to allow the use of the Honda GXV390 vertical crank engine. We have, of course, been keen to find an alternative to the Tecumseh, which has now been out of production for about 7 years, and we are confident that the Honda GXV390 will fit that bill and help make engine choice easier, especially for new members building mowers.
We also aim to test the Loncin 413cc vertical as a cheaper alternative to the Honda, as the 452cc engine proved not suitable. The plan is to test other engines including a diesel in the near future.
In a further move to help widen engine choice, the engine orientation in Groups 3 and 4 can now be changed from vertical to horizontal and vice versa. This will enable people who want to run a horizontal the opportunity to use a cheaper chassis as well as the engine of their choice.
If you do wish to take advantage of this rule change, you must contact the race committee.
The complete list of engines currently approved will appear in the new 2015 handbook when it is published shortly.