Hey guys, I'm working on a new to me D model Aztec with IO-540-C4B5 engines. The plane is in the shop for an annual right now and I noticed this spacer between the fuel injection servo and the oil sump. What is interesting is that one engine has the spacer and the other one doesn't, which is why I'm trying to figure out why someone added it in there.
Looking at an IPC, Lycoming does appear to specify a spacer on some engine applications. It does not appear that the C4B5 is supposed to have one so my thought is to remove it. However, I'd like to know why Lycoming used these on some engines. Does anyone know?
Both engines seem to run the same, so whatever it was intended to do doesn't seem to affect engine performance.
Looking at an IPC, Lycoming does appear to specify a spacer on some engine applications. It does not appear that the C4B5 is supposed to have one so my thought is to remove it. However, I'd like to know why Lycoming used these on some engines. Does anyone know?
Both engines seem to run the same, so whatever it was intended to do doesn't seem to affect engine performance.