Michael gave me a gentle nudge stickpoke stickpoke this morning, to remind me about finding a little engine that I used to work on many years ago.
You usually have to remind me to do things as my memory isn't as good as it used to be.
This is about the only complete 061 (1cc) engine that I still have that started to have mods done to it. The Cox series were not as robust as this one as they were usually a different design, using a rear induction reed valve. This one has front induction with an R/C carb.
Basically, to get it ready for use in a model boat, all that was required was to fit a front bearing to take the weight of the flywheel and to water cool the combustion chamber because it would not have air flowing thru the fins if buried down in a hull.
So this is the engine stripped down to it's component parts, except for the silencer, as that just fit as normal with no mods.
The first thing that was done was to modify the nose of the crankcase to take the large slimline ball race, making sure you still left most of the bronze bearing that was already in there. This called for VERY accurate machining to make sure that they were both in line, otherwise the crank would just jam up.
The water jacket was made by silver soldering together two parts, the outer had fins on to aid with cooling, and the inner section had a channel cut into it that allowed water to flow around inside, from the inlet stack to the outlet stack. You didn't need to have too much water thru it, otherwise you could cool the engine too much and it wouldn't get up to working temp, and thus max power. A little clamp on the inlet pipe allowed you to fine tune the flow. The water was supplied by a little bent tube facing into the flow of water from the propeller under the back of the hull.
A side view. The hole in the centre was bored to be a wringing fit onto the previously machined cylinder, which had the fins machined down to a very good parallel fit.
This is how it fitted, clamped down by the cylinder head. No water actually came into contact with the original parts of the engine, the heat was conducted away purely by the surface areas in contact with each other.
As I stated before, I would have loved to have been able to do this mod on an 010 sized engine, but it seems that no one does the micro R/C carb conversions any more, they are just a start and scream engine.
Bogs
