The Weston 3.5 cc "Stunt Special" was the final engine produced by (or more probably for) Weston Model Aero Supplies of 1 Oxford Street in Weston-super-Mare, Somerset, England. This firm was actually a model shop specializing in control-line supplies as opposed to a manufacturer per se.

The Weston "Stunt Special" had been preceded in the Weston catalogue by three models designated the Weston "A" (0.25 cc), the Weston "B" (a 3.5 cc side-port unit) and the 5 cc Weston "C". Although the "A" and "C" models were advertised over at least a six month period during 1948, there are no reported surviving examples of either. A few examples of the 3.5 cc side-port Weston "B" do reportedly survive.

The Weston "Stunt Special" appeared in early 1949, replacing the Weston "B". It was a lightweight crankshaft front rotary valve (FRV) diesel of reasonably up-to-date design. A test of the original version by Lawrence Sparey appeared in the June 1949 issue of "Aeromodeller", but this did far more harm than good to the engine's prospects since Sparey encountered a number of structural difficulties, all of which he reported. A revised Mk. II version was quickly developed, but the damage had been done and the Weston "Stunt Special" faded very quickly from the scene. Only some 20 examples were reportedly produced in total.

My own testing has confirmed that the Weston "Stunt Special" was a far better engine than Sparey's report would indicate. A full review and test of this very rare diesel may be found elsewhere on this website.