Ivan's 67 ( White One )

Today we are seeing if Ivan's 2007cc engine case , that has worn lifter bores ( one badly ) , is repairable by fitting aluminium sleeves . The sleeves are 24mm OD , the lifter bore that was badly worn was reamed out gradually , to see how bad the damage was . We were hoping that the bore would clean up before the 24mm size was reached .
Luckily the bore just about cleaned up , there was a tiny mark left at the bottom of the lifter bore , but it was so minimal that we decided to fit the sleeve and see how it went . On the advice of John Maher , who built this engine 11 years ago , he advised machining the rest of the lifter sleeves down to 22mm , so as to leave as much of the original lifter boss intact as possible . Ron , my engineer friend , reamed out the lifter bores to 0.02 mm interference fit ( As per instructions ) , with the machined down lifter bushes . We heated the case with two electric fan heaters and put the bushes in the freezer . Ron made a drift that sat inside the lifter bushes , so they could be pushed a little way in to start , with the Bridgeport mill , then hammered home . To finish the job , Ron machined a chamfer at the top of the sleeve , to allow the lifter to sit flush with the bush . The porting sticks that I use , just happened to be exactly the right size to run up and down the fitted sleeve , to leave a nice even honed finish .