RE: Patriot 40 temp engine
As noted, the dimensions are on the website.
The mounting hole pattern is the same as the OS46. So in that respect it will match up.
I am about 80% sure the distance to the drivewasher is the same too
The cutouts required for the carb will be different.
The muffler installation will be different (most folks have to sand the underside corner of the fuselage just a LITTLE bit to clear the muffler)
It is also useful to mount the Jett needlevalve on the airframe. Planning ahead for that is helpful when building.