As you may or may not be aware when I stripped down this engine I'm rebuilding one of the bigend crank journals was a bit battered.
I was hoping it could be reground but it's too far gone, so new crank it is.
On inspecting the various engine parts I found out the reason for the beating to death journal. The conrod was at fault, the dowel on the endcap didn't quite fit the recess in the conrod and I suspect whoever did it last had torqued the bolt down but hadn't managed to get the two parts to fit together.
The extra resistance of the overly tight fit between the two parts meant that the torque figure was reached before the cap and rod had been drawn together, resulting is an excessive rod to crank gap. This in turn caused the crank journal to take a hammering , the like only seen in a blacksmith's shop.
The hole has now been reamed out and it all fits as it should.
Next question is... Can anyone verify the piston to bore clearance for +20 county pistons in a 1300 engine?
I believe it should be around 0.002"-0.003"