4A084 Motor Mount

[XL-C-100]

I am in the process of configuring a motor mount for my 084 surplus engine, I am planning on modeling it after this photo of a mount on a cub. I have been having this reoccurring thought and I have to ask the question. Why in the case of the Legal Eagle are the motor mounts bolted to the fuse instead of just welding them to the first station?
Somebody please let me know what I am missing? 

[Bugsmasher]

Modular service...if you develop a crack in the mount...it will make it a lot easier to repair off airframe. Plus it allows swap out to another style/size power plant. I don't know of any production airframe that has integral power plant mounting. Need to keep things serviceable / replaceable. Big weight savings can be had if you fab up a .080" aluminum oil pan....that thing is nearly 10 lds ! I don't think it plays any role in crankcase strength....may want to investigate further

[Bugsmasher]

Smooth...gotta give it that.

[Dan_]

I am in the process of configuring a motor mount for my 084 surplus engine, I am planning on modeling it after this photo of a mount on a cub. I have been having this reoccurring thought and I have to ask the question. Why in the case of the Legal Eagle are the motor mounts bolted to the fuse instead of just welding them to the first station?
Somebody please let me know what I am missing?

I am not sure I understand your question, but the Legal Eagle motor mounts are welded to the front end of the fuselage (full case engine).  Cut case engines need an extended mount due to cg requirements I would assume.

BTW:  The engine pic you sent is a conversion by Les Smoot.  Probably no one on earth has worked on more of these 4AO84 engines than Les.  He has been converting them for aircraft use for several years now...

A video made by Les, explaining a lot of what you see in the above pic has been placed on the home page...

[ray_pilot]

Where did you get the prop hub?  Thanks.

n247rf@gmail.com