Originally Posted by Bryan Miller
A friend of mine purchased a 3 bearing block for his Formula Junior project which
turned out to be a 701M 6015 block and given that casting number you would expect 5 bearings , the block was not modified in anyway to remove numbers 2 and 4 mains , so these were specially cast by Ford in period .
He neglected to check casting number prior purchase and presumed it was a 109E 6015 block.
Block sounds a very interesting Bryan, I presumed the bearing housings would be just ground or machined away.
Maybe re-casting was needed to block the oil galleries. Has your friend found out where it came from?
I have reaad that the F3 1973 twin cams had to run airboxes with restrictions, but could they run steel cranks and rods?
I guess running a restrictor would mean the use of big valves and race cams was a waste of time?
Maybe better to develop a three bearing crank with lower friction that with lightweight pistons would rev free