The latest news in the Ottawa In Oz Saga is that she is now running again. I have to say JB Weld is King! I got some quotes to weld up the busted part of the head and it was just too much for me right now. Seems no list members in Melbourne were willing to have a go either... Such Is Life.
To cut a long story short, I cleaned up the edges of the break on both pieces with an angle grinder with a heavy duty wire brush and then later my dremel with a grinding bit. I cut a V groove just like you would if you were going to weld it. While I was there I used the dremel to clean up the combustion chamber in the head. The head looked almost flat to me, to my surprise the dremel opened out about 4mm of space from just carbon and rust! I then expoxied the pieces back together with JB Weld applied generously making sure all the bits were lined up perfectly. While I was at it I fixed the broken rocker arm bracket and the little chunk missing out of one of the rocker arms. That was last weekend. I waited until today, then put it all back together. Used a new gasket made of nice asbestos fibres with metal sandwhich. Liberally applied Permatex Form-A-Gasket to both sides and both faces. Waited the prescribed time, then bolted everything up. I waited a while for the Permatex to set then poured some water into the hopper, so far so good, no leaks.
I moved the engine out to the grass and nailed it down with 10" long spike nails through some holes I had previously drilled in the skids (you need to do this because it bounces around so much due to its slightly bent flywheel).
Cranked her over a few times, made sure nothing was hitting anything in the head, closed the compressor release and spun her over - off she went. Oiled everything up. The new long stack sounds good. The engine runs really well. Ran her for about 10 minutes then checked all the bearings including the newly repaired wrist pin journal. Everything was cool. Started her up again and ran for about two hours (much to my neighbors disgust).
The new journal is excellent - no more knocking. She runs so quiet (don't you always like how we engine people describe the word "quiet"?) now you can hear the timing gears whirring.
I cleaned up the face of the flywheel using a oiled bastard file first to clean up all the nicks in the rims (frequently cooling in an oil bath), then oiled sand paper to get rid of the paint and rust. The previous owner did not derust, he just put on more paint until it was smooth.
After a couple of hours, I stopped her and gave her a wipe with an oily rag, then let her cool before dumping the water out of the hopper. All put away now.
Only four jobs left:
- clean the black paint off the wico - they look so much nicer polished than painted - anyone got any idea how to do this without destroying the brass? I've been thinking of a cotton buffing brush and cutting compound?
- replumb the fuel with copper instead of the modern rubber pipe;
- make a bracket to hold the exhaust pipe in its "new improved" upright position to reduce strain on the head; and
- straighten the flywheel - I doubt I'll ever try this one - cannot afford to break it, after all, where would I get another one from? I have a "spare" which has radial cracks in the hub, so it will never run - I guess it will become a letter box post or something [:)] .
All in all, a good day. As usual I'm covered in crap... time to go out and put together the kids bikes together (which is what I went to the garage to do in the first place - good thing there is not another engine needing attention out there!)
Update 2009 - I should point out that JB Weld turned out to be unable to handle the pressure and it blew out again some time later. I had the head welded by an exeriened welder that worked with cast iron. Cleaning out the expoxy was a bugger of a job.