15-11-2022, 11:05 PM
(15-11-2022, 12:42 PM)Austin in the Shed Wrote: I have machined hundreds of castings over the years but not attempted to machine a new crankcase although I have one as a " retirement project ".
Having a casting is one thing,but is it dimensionally correct,missing any bosses etc,porous anywhere particularly around the oilways?
My Flake 10 stud blown crankcase was deficient in the centre cam bearing and that had to be buttered up before line boring.
Overall Austin had trouble boring crankcases accurately, as we know from the different sized cam and front crank gears. At the tail of the camshaft they varied even more. I've measured the rear of the cam being up to 20 thou out of parallel with the crank. My theory is that they machined the oil pump position first and then put the cam rear bearing in the place to suit the oil pump gear mesh. After all, with Austin radiused tappets the cam being out of square didn't actually make much difference.
Charles