Hi there, do a search on blowers, there is a thread not long ago that had lots of discussion. Timing should be boost referenced to avoid detonation. Carby needs to be set up to supply enough fuel for the air being rammed into the motor. Also need to avoid having to high a static compression on the motor as it will give you problems. Blowers heat the air during compression which can cause detonation if there is hot spots. Lots of variables, a cam with excessive overlap will bleed dynamic compression out of the cylinders which which will prevent detonation, reducing overlap will give more power but will make detonation more possible.