An acquaintance of mine in England had bought a set of castings at about the same time as me and gone on and built his, but had made a simplified con. rod, which I did not want to do. His simplification was to make the big end what could be described as a piece of bored out bar and silver soldered it to the stem. He did the same sort of thing for the small end.
Fast forward to March 2016. I got a challenge from matey to bring my completed engine to the Bristol show in August. How could I refuse that challenge?!
The first job was to make a new ball turner. I ended up with a version of the ubiquitous Steve Bedair design. I would have liked to have mounted it in place of the top slide, but did not have a large enough piece of steel to incorporate the mounting stub into the base, so it sits on the cross slide and is secured by a tee bar (long tee nut).
The new con. rod blank was the 'other bit' from the previous effort. Same procedure as before, but this time using the new larger capacity ball turner. This pic shows the big end being turned and well under way.
This time all went well and the con rod was turned and shaped satisfactorily. So now over to the milling machine and mount the part in the vice on parallels. The securing doesn't look too safe, but I couldn't think of any other way of holding it and not disturb the job while boring each end. Taking light cuts, there were no mishaps.
The last piece that I had to make was the inlet valve spring - this was a tapered item. I hunted through my spring collection and even responded to an offer of taper springs from a contributor on this forum. They duly arrived but unfortunately the larger diameter was too small.
I'd never wound a spring before and kept putting the evil hour off, so now was a good time to try my luck. I made a spring winding guide based on the design by Dwight Giles in Model Engine Builder magazine.
Then I read up about making springs on a very good site
http://web.archive.org/web/20130918155928/http://home.earthlink.net/~bazillion/intro.html
I made a tapered arbor and put it in the 3 jaw chuck. Engaged the coarsest thread on the gearbox (4 tpi) and went ahead with gay abandon. I should have paid closer attention to my study because starting at the small end and winding uphill, the coils just slid down the taper and I ended up with a tension spring instead of compression. Remedy was to stretch it out afterwards.
This is a posed picture of my efforts after the job was done.
All that was left now was to paint and assemble the engine and mount it onto a base.
My wood working skills are even poorer than my metal butchering, so something simple was required, especially as time was of the essence. I had some suitable ash wood about 7/8" thick that I cut into 8 strips, dowelled and glued them together. Two other strips formed the runners. The whole lot was sanded down and varnished.
Finally with 2 days to spare before setting off to England it was ready. I didn't have time to fit an ignition system or fuel tank, but I was happy to see the construction complete.
Some time after getting back home, I fitted the ignition system and rigged up a temporary vapour carb.
Not a pop could I get. I have compression so I am wondering whether my vapour system was man enough for the job. Next I will try liquid fuel and will report back in due course with results - positive I hope. In the meantime, that's all folks.
Dave
The Emerald Isle
