Sexton R975-C1 a mess

[Bob Phillips]

Not sure if I should weigh in here but..here goes..
Before you do anything else you need to strip that engine right down and see what you have to work with. If the case, crankshaft, gear case etc are rebuildable- all the rest of the parts are easy to obtain. You will need to really check for cracks and damage carefully. Second, while some parts between the C1 and C4 interchange, many do not. The crankshafts are different and use different bearing retention in the front, slightly different rear mains etc. Third there are many aircraft engines that have been flogged to people to use as spares- notably the post war R975 -46 which was a helicopter engine- though it looks a lot like a C4. It is an entirely different animal with few interchange parts. Be careful you don't get stung! Fourth, it is easy to destroy a C1 engine. I recall the overhauled engine in Bill Greggs Sexton having the bottom jugs damaged when safe start up procedures were not followed. Most of the many engines I have seen had bad main crankbearings- hardly surprising given the design and the design expectation that this would be an aircraft engine. Finally lots of parts and core engines are available right here. Tear that engine down and see what you need!