Hello Randy,
Still having problems with photos, so thanks for your photo of what I think of as the old OS Max 35. This is the one prior to the FP series, I believe. It has a one piece die cast crankcase with a drop in liner and the plug in a central position. The engine that made me post, is an earlier type with a solid, finned steel liner and the plug is displaced towards the transfer side and it isn't canted, but upright.
I have read stories about stunt fliers going from Fox 35s and using the new OS Max 35, which had more power. It gave good stunt runs when new and tight, but as things settled down, it could exhibit the dread runaway. It also had a reputation for eating rods.
I assume the engine I have is this early type? If so which is the better engine for stunt application, the solid steel finned early version or the later drop in liner type. I want to build a classic plane using a stunt Max 35, hence the query, it is just a nostalgia exercise! so nothing serious!
Regards,
Andrew.