The locations of the bolt holes in the bearing flange were transferred to the frame by clamping the frame to the mill table raised up on two blocks, dropping the bearing into the main hole, then finding each hole with the drill and drilling through. Dropping the screws into the holes one by one as I drilled them contributed to keeping the alignment. My pictures of this operation in progress turned out blurry so I didn't post them. Here are the resulting holes, though:
The bearings were then fitted to the frame with the bearing flange and the collar clamping the frame between them when the screws were tightened:
Later I'll change the screws for nicer ones and drill oil holes through the collars and bearings on the inside faces of the frame plates.
The engine was temporarily assembled once again but this time with the bearings properly installed:
This enabled me to measure what will be the width of the finished engine. I will now fix the frame sides to a temporary base in the form of this piece of plywood and fit bracing pieces to stabilise the whole thing in preparation for an air test. For this the end of the piston will need to be fitted with a pin which will open and close the valve.
As noted previously my only serious concern at this stage is whether or not the flywheels will have enough momentum to turn the engine over. If they don't, I'll just have to enlarge them...
