Is the following correct?
Merlin, crank rotates clockwise, prop counter clockwise when viewed from the front, wants to swing to left on take off when viewed from cockpit
Griffon, crank rotates counter clockwise, prop clockwise when viewed from the front, wants to swing to right on take off when viewed from cockpit
Based on the following
Vintage Wings of Canada Merlin engined Spitfire XVI
“Ease the power in sloooowly. It is not visible to the spectators, but that big propeller will give some remarkable asymmetric forces on the take off roll and, with a max power take-off, you will need full right deflection of both aileron and rudder to keep it straight.”
Regarding the options with spur gears.
Unlike the Mosquito which had both props rotating the same direction, the Hornet had props that rotated in opposite directions.
Both Hornet Merlin engines rotated the usual direction but one had an additional shaft in the reduction gear to reverse the direction of prop rotation.