This is my latest engine recently completed. The design is by Aussie Ed Holly, who has made his drawings for it freely available. As drawn, it is a boxy, all bar-stock design. Eds intension being to encourage people to have a go at making an I/C engine. In his notes with the drawings he suggests that makers might like to alter things to make the engine unique to them and I have done just that..

The Crankcase as drawn has a radial mounting, This has been changed to a beam mount I have lengthened the crankshaft to allow a spinner in place of the plain nut. Added a bronze bearing to the front housing that also has a single ball race. Also changed to a split collet for the prop driver in place of the fixed taper.. The Fins and Cylinder were held down by four long screws,but I have put a thread on the Cylinder to allow the fins to be screwed down. Cylinder height was increased by 0.375"as the Contra piston,as drawn is too shallow for the method I use to make them. I put about 0.005" taper to the outside,with a thin wall of about 0.020",.Diameter is then turned with a good finish to allow it to enter the cylinder for half its length. This will then push into the cylinder giving a gas tight fit with the Screw fitting.For the last three engines I have made this from EN1A,rather than C/.I . I smear copper loaded grease on it on assembly to avoid any chance of seize. Cosmetically I have tried to soften the appearance. The Fins , Prop Driver and Spinner are anodised and the crankcase has been bead blasted to give an overall smooth mat finish. To add to the "bling" I added blue S/S mush head screws.

It has proved to be an easy starter and to date it has had five runs of about two minutes each, running rich ,with a 10"x 4" nylon prop, RPM at this stage is around the 8000 mark. I have several props of other size to use on later runs.

Putting potos on here is a nightmare! Why do they end up in the reverse order that I click on them? I would expect to start at the top of the list, not the bottom.

Keith