engine performance tips.
increase intake size, cool intake air, increase exhaust
size, preheat diesel fuel
prior to injection, thats about it, i dont think that you will get a fan that will aid you that much. Would a fan be able to create damage to your engine,...only if it gets sucked into the engine.
If you want more boost then add a turbo, it will cost you a little bit if you do it yourself but will improve performance and economy if done right.
if your particular motor
was ever released in a tractor or a vehilce of any kind that was turbo charged then you need to find what type and then scrounge the wreckers not that hard.
or just find something of a similar displacement
The just a little fabrication to suit you current