I don't know. Usually a turbo charged engine will have a slightly reduced compression ratio for the engine to internally handle the added strain of turbo charging. The Kubota engine in our 770 Bobcat is a 4 cylinder Turbo charged Kubota diesel. I don't know if Kubota builds this engine differently than the tractor engines as I don't have a shop manual on it. Kubota builds engines for a lot of specialized equipment manufacturers, from generator manufacturers to Bobcat's. I was wondering what would happen if I fabbed an intake manifold and added a turbo to my 5030. I'm sure I'd have to at the very least, install a thicker head gasket or spacer plate to reduce the compression ratio. Beacuse the engine has overhead valves, I'd need longer push rods and a bunch of other parts so I probably would not do it. Besides, it's new and under warranty. Maybe in a few years, but by then I'll trade it for another one anyhow.
In a nutshell:
Most engine manufacturers don't redesign an engine for turbo charging, they just lower the compression ratio to a manageable level. If you turbo charged an engine without reducing the compression, the internal heat and stress from the added air charge would destroy it.
Daryl
Forage Services, L.P.