As parts sources dry up, and the skill set involved in fitting Babbit bearings on the old inlines also becomes a lost art, we're either faced with scrapping the old stuff, or finding a work-around. The old stovebolts were way over-engineered for the amount of power they produced, so it's possible to dramatically increase the performance and reliability without going to some modern "belly button " (everybody's got one) small block V8.
For those engine builders who are interested in less radical modifications to the spray-oiler sixes, it's possible to machine Babbit connecting rods for an insert bearing for a Perkins Diesel engine, and regrind the crankshaft to fit the new bearings. That takes the Babbit rods out of the equation.
Jerry
