Engine torque twist direction.

[HrdnSwede]

Weird title huh?
Simple question though: Which way does the engine in a XS want to twist when you gas it? Backwards/up for a wheelie or forwards/down to keep on the ground?

Reason I ask is because I haven't gotten my project running but like to know which way to eventually 'preload' the engine to take out slack from the engine mounts. Doing a bunch of custom fab work including exhaust and the difference in movement up/down right now with just the bolts sitting un torqued/tight makes a difference where things will fit and clearances that will mater later.

 

[Jim]

On any powered device, the "torque" direction is opposite the "powered" direction. Spin a drill and grab the chuck.... the drill body will "torque" in the opposite direction of the drill rotation.

 

[Signal]

I think you are over thinking this.
The engine cases have circular recesses cast into them. Engine mounts stock or custom should have a matching raised circular area to match the engine casting recess. When the engine is bolted up tight this method stops the engine working on the bolts and flogging the cases out.
Bolt your engine in and tighten it up and it should relocate to that position ( with some tolerance) next time you remove /install it once your dry build is finished.

 

[TwoManyXS1Bs]

There was *some* bike back in the day, twin, engine ran backwards.
You couldn't wheelie the thing...

 

[Max Midnight]

The majority of motors until recently ran forwards i.e. the same direction as the wheels.
However in Moto GP Honda reversed the direction of rotation as this reduced the the tendency to wheely and made turning in easier.
The other manufacturers followed suit and now Ducati in the production V4 Paginale followed suit and the may also be others.
The downside of doing this is added complexity of the additional gear required to turn the gear clusters in the right direction and a small loss of power.

In the XS none of the above is relevant and as Mr Signal suggests you are probably over thinking the matter.
I wouldn't expect any movement twixt motor and mounts if they are fitted and torqued correctly.