After my last project I decided I wanted to do something relatively easy. I dug into Elmer's book and decided on the number 4. It doesn't seem to be one of his most popular engines but I decided to give it a go.
I started off by squaring up a piece of aluminum to be the column. Then I drilled starter hole for the crankshaft and the four pivot holes.
Next I turned up the bearing and drilled it out.
The column was put onto the lathe and I drilled the center hole out to 3/8 using an end mill to get a flat bottom.
Then I bored out the center hole to take the flywheel.
Elmer calls for peening the bearing into the column. I have never had good luck with peening and this was no exception. While the bearing was retained ok it would spin in the hole. I ended up putting some Locktite 603 on the joint. I spun it around a few times and let it set. That seams to have locked it down.
Next I made the jig for positioning the port holes.
Using the jig, the ports were laid out and center popped.
The intake and exhaust holes were drilled part way so as to not interfere with drilling the intake passages.
Then the primary intake passages were drilled up from the base side to intercept the intake ports.
Then the cross port and mounting holes were drilled and tapped.
Then I extended the ports to meet the passages and drilled the exhaust ports all the way through the column. Naturally on the very last exhaust port I broke the number 56 drill in the hole. The port was drilled out, plugged and drilled finishing the column. The Next part was the base. I squared up a piece of stock and drilled the mounting holes. Then I counterbored the column mounting holes for socket headed cap screws.
Then the base was flipped and face milled flat.
That leaves us with this.
Till next time.
Tony
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