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Archive for November, 2019
Posted by Geoff Potter | Nov 05, 2019 @ 07:10 AM | 1,019 Views
Motor Cycle Pete sent this over to me as it had a pretty sad crank to crankcase fit , and asked me to grind and chrome and grind again back to size . I set it up in the grinder between dead centres and it took 5 thou off the diameter to clean up all the damage and out off round . There was no bush in the crankcase and the damage was pretty bad so I decided not to chrome the crank but make a bush for the crankcase and fit it to the slightly smaller crankshaft . I made a bush out of cast iron with a 2 thou interference fit in the crankcase hole that I bored on a jig I machined in the lathe . Pushed it in with the tail stock quill and some loctite , so I don't think it will move .
While it was still on the mandrel I bored the crankshaft hole in the bush and reamed it to size with a machine reamer and checked the size of the points boss and it was oversize so machined it back to the right size .
I then took it off the mandrel and held it by the boss in my smaller lathe and machined off the rear of the bush and cut a chamfer on it and tried the shaft , was a great fit .
I took it back over to Pete and he can put it back together for Condo , should be a very good engine ....Continue Reading