mills diesel 1.3cc assembly model ic engine

Session 1.

All parts have been cleane,d by firstly putting them in an ultrasonic cleaner. I was
amazed at the amount of dirt that came off them!. This was followed up by cleaning
the dried parts in thinners before placing them on clean paper towels.

The parts were then assembled with som light machine oil in the relevant places. All
went well and there were no problems in final assembly. It was then over to the
nervous stuff. Starting her...........

I followed Ron Chernich's guidance notes in his article and tried flipping the propeller
with a little fuel placed against the exhaust port when the piston was covering it. After
a couple of flips the compression screw was tightened a 1/6th of a turn and the
process started again.

The compression seemed good to me be it is nearly 50 years since I last had a diesel
engine to 'play' with. However, no matter how hard I tried I coun't get her to fire. My
back was very painfull because of the starting and I decided to call it a day.......

So I tried to make a fitting to run in an ellectric drill with forks going over the propeller but fixed in such a way as to kick clear
(hopefully) if or when the engine started. Using this tool certainly made turning the engine over but still now joy in starting
her.....I have decided that since I have been concentrating soley on the engine for a while, I will leave it and start on the Fowler
traction engine, coming back to the Mills later. So it ended for the moment in dissapointment.

Session 3 19th August 2008

Today I felt sufficient time had passed to have another go at starting the Mills. Reflecting over the period since the failed
attempt the session before, I decided that this session I would comlete two tasks. One, refine the starting adaptor and
secondly, to disassemble the engine and check the fit of the piston and contra piston as logic would say that since in only fires
when compressing the fuel mixture sufficiently to cause it to explode, the contra piston and/or piston/cylinder liner are the
points to concentrate on.

After taking the Mills apart I found that the piston did fit as per Ron's article. The liner had a good mirror like finish and correct
taper but the contra piston wear marks seemed to suggest it may not be sealing fully. So I made another contra piston but this
time a tighter fit. It may be a little too much, because I adjusted the size before polishing, to be a little larger.

The engine was then cleaned fully before rebuilding with the new contra piston. I again tried to start her as before but this time
from the start, I used the electric starter. The compression, which I was pleased with when she was built first, was greatly
increased now! With renewed confidence and vigor, the process of finding the correct compression screw setting,
commenced.

After a few turns on the compression screw I was pleasently surprised when there was a puff of blue smoke and a certain
smell......and she definiteley fired! I thought the best action was to now try and start her by hand and stopped using the electric
starter. However it didn't take long before the pain in my lower back told me to stop.

I decided that since I was so close I would stop for the day and have another go tommorow, hopefully with success. I may
well make another piston however as taking the engine apart is a relatively simple and quick process. If the contra piston made
that much difference then a more highly polished piston slightly tighter, may prove benificial.

So the next session will start with making a new piston. I will try to start her again at the settings she is at but it doesn't take
much for me to suffer and I want the chance to complete the piston before having to stop. Only time will tell. However on a
positive note, she definiteley fired! So she should do so again.....shouldn't she....yes of course she will. I won't give up, she
must be gotten to work!

3rd September 2008

Full of enthusiasm I went out into the garage when not feeling my best. The cast iron had at last arrived and I hoped to get the
engine running today. However I am just as far from the end, in fact slightly worse off!

When looking at the parts I thought that since I was at it I would not only make a new piston but the con rod and gudgeon pin as
well. That way I would have a complete new assembly and they could form spare parts for the future. As said before I was in
quite a bit of discomfort, but progressed fairly well in making the new con rod. The blank was machined to size. The little and big
ens holes were center drilled, drilled then reamed to size. The insets were milled in and then the con rod edges milled to shape.
All that was left to do was to mill the radius on the two ends. And it was whilst milling the last ^%$�� one that I didn�t
concentrate enough and the end mill grabed the con rod! So that was that I stopped work and instead of trying to get the engine
to run with a new piston, I hadn�t even started on the new one! Grrrrr��

So its another tommorow........ It will be another new conrod, pin and piston.....tee hee......