GTW GP9R question

The EMD 567, 645, and 710 engines all use camshaft counterweights as part of the engine balance solution. When you make a change in the weight of the reciprocating components, you make a compensating change in the camshaft counterweights. Since the camshaft counterweights are hidden from view when the engine is assembled, this is not very obvious unless you have actually worked on EMD engines.

PCook, thanks! I learned something new. I reasoned that since the pistons and rods were changed, there was a different reciprocating weight affecting the crankshaft so those counterweights would need to be changed. But I figured that other than perhaps a different setting for valves and/or injectors, there would not be much difference for the cams at all, as they are gear driven and it would not seem they would be influenced. I will adjust my figuring, LOL.

While we are on the subject, though, are crankshaft counterweights also changed when making this conversion?

2spot wrote:Dutch Railnut and BlackDog are correct. 645 power assemblies on a 567 block for simplification of parts inventories. They still rate these at 1750 HP. Sorry if I left that unclear.

The VMV (Paducahbuilt) GP10's and GP11's were based on that same principle I take it as well.

Sidenote, VMV fabricated the cabs and fuel tanks, to name a few, for the Grand Trunk GP9R program.