Engine mount changed thrust line.
 

My second WM SS40S has arrived a she is almost ready to go, however, when I realised that S version of SS40 has a nose cowl I began thinking of ways to keep as much of the cowl as poss, and save some cutting work.

After looking at the options and the work involved to mount the engine other that vertical, I thought of an other alternative,

Is it acceptable to mount the engine under the mount ie; hang it from the mount instead of sitting it on. Effectivly lowering the engine about 5/8''. This will allow far less cutting and shaping of the cowl and hide all of the exhaust outlet.

Is there anything fundermentaly wrong with this, am I missing some technical aspect of changing the thrust line. I checked the engine mount and the engine seat and they are all good.
I have used 3.5 cap scew machine bolts with washers and nylock nuts to mount the engine.

RE: Engine mount and Cowl Cutting.
 

I don't know if there would be a problem with the mounting method except you would definitely be lowering the thrust line by the thickness of the mount. That may or may not make a difference.

RE: Engine mount changed thrust line.
 

it will lower the thrust line,
but if it is a trainer, a little
trimming should do it.

RE: Engine mount changed thrust line.
 

It would be acceptable if the underside of the engine mount beams are parallel to the top side -- however, they often aren't. If not, you will have to shim either the mount on the firewall, or the engine on the mount, to bring the engine back into correct up-down alignment.

RE: Engine mount changed thrust line.
 

britbrat is exactly right.......often, the bottom of engine mounts are tapered....make sure you pay attention to this.

RE: Engine mount changed thrust line.
 

But if this is the case you might be able to invert the mount and mount the engine on what used to be the top.

Terry

RE: Engine mount changed thrust line.
 

Hi again Terry, That is exactly what i have done. I think it has turned out OK for my first attempt at cutting a cowl.
I hope this one lasts longer than the last one :D


[img][/img]

RE: Engine mount changed thrust line.
 

Smoggy,

Just make sure all this doesn't confuse the plane over which is up and which down:):):)

Good luck


Terry