I'm looking for information on the RR/Allison 250 B-17, specifically info pertaining to maintenance. How often does it have to be overhauled? How much does it cost for an overhaul? Would someone need a lot of special tools that are specific to that engine (such as a rigging kit)? What are people's experiences with these engines? I'm not asking anyone to do my research for me, but I'm hoping that you all can point me in the right direction to where I can find these answers.
While I'm at it, where can I find the same info pertaining to the Lycoming TIO 540? The reason I ask is that there is a kit plane out there that offers the two engines as options.