Superior IO-360 Alternate Air

My RV7 project is beginning to move onto the engine.
I have an IO-360 Superior engine. As I am injected I understand I won't need carb heat - but I have been advised I need alternate air. I have had a quick look through the Firewall Forward book but not found any information so far.

An overview, links or advise would be appreciated.

Alt(ernate) air is in case your air intake or filter gets blocked. If you have a Van's air filter use their snorkel and alt air door. If you are just using a hole/trumpet in the cowl in front of the injector, put some fine gauze over the hole and make sure there is a 1/2" gap between the cowl injector - if the hole gets blocked the injector can breathe from inside the cowl (take a look at an Extra 300 cowling if this doesn't make sense). Dan Checkoway also has a different solution.

Pete

Pete,

I finally found some info late last night in an Engines book. Makes sense now. As the airbox in Vans FWF kit has a flap.

Thanks for the info.