I know it's probably been asked or discussed a few times on here but I didn't know what to ask for in the search engine....so here goes. Picked up a Collari AAC motor (.21 onroad)new(but no instructions or box)....is there any difference in the break-in procedure for these AAC types versus ABC type engines? I've never owned an AAC engine and I want to make sure I break it in right? Thanks

Come on guys....someone has to know about breaking in one of these engines. Chime in here!!

The same way as ABC. AAC is very good set up for really cold weather and acting strange in hot ambient. I try it in the past and RC cars is not perfect aplication for AAC. Also 21 engines has too many ports and there is high posabilities that bridges between ports will brak-it happened many times in the past.
Edward

What does AAC stand for? What are the advantages of an AAC engine?

Sean

Alum piston-Alum sleave-Chrome plated sleave.
V.S. Alum piston-Brass sleave-Chrome plated sleave.

AAC is lighter. Originally developed with the idea that the expansion rate would be the same between piston and liner. Thereby maintaining compression when engine hit temp.