Some extra hints from Harry Pyle on the usage of modern blowers and rubber hoses

The AMR 300 and 500 blowers, and also all modern rootes type blowers come from modern fuel injected engines, and as such they only blow/compress AIR..not petrol/air mixture. Because they only pass air they can get away with any type of rubber/material hose and the flexible type mount.
If used on older engines where the blower sucks petrol/air and then compresses it into the engine..the blower should be rigid mounted onto the manifold..and the carby also rigid mounted. The pulley belt is tensioned by a swinging adjustable pulley suitably mounted off the block or blower itself. The carby/suction manifold and also the head/pressure manifold should be bent tube/pipe NOT flexible hose.. (In the case of Robert's sv motor, called the block/pressure manifold).
If a joint is needed, then use quality radiator hose. Always use MINIMUM length hose on the joint..if a bend is needed, put the bend in the pipe NOT the hose. On the carby/suction pipe there needs to be a "stint" inserted into the hose at the joint to prevent the hose collapsing/pulsing because of the suction. On the engine/pressure pipe the hose will need a series of closely spaced hose clips to prevent the hose bulging/pulsing because of the pressure. If the mixture is correct, any hose used will only ever have minimum exposure to petrol. If you can source the correct diameter hose in Neoprene or Viton or similar, then I suggest use that.
I hope this helps.
Kindest regards
Harry Pyle