I run the Sirio about 220-250 and have run it a little lean at 270 without problems (was for 3-4 laps max). I have about 1.5-2 gallons through it. All Sirio's from my experience and what I have heard (I own 2) is that they come alive after a gallon and this is true on both the engines I have. Don't get me wrong that first gallon they got power, but after a gallon it's insane. I am still running the restrictor and a crappy pipe and they engine is an animal. I will go buy a speed gun to test it at the bash and I will have witnesses as to how fast it goes. I beat a 2 speed NTC3 with the .15 outlaw Sirio engine by far and I would guess that thing tops out at 55-60 so dunno on the top speed thing but I thing 45 is WAY slow......... maybe on dirt.
I got the engine for like $270 I think.
and AAC is supposedly better or tougher (takes more wear) than ABC.
you supposedly are going to get 3-5 gallons out of the AAC race engine as opposed to the supposed 2-3 gallons out of an ABC
also AAC is substantially lighter than ABC almost an ounce
this is what I found here
http://www.jettengineering.com/faq.html
Question:
Is an AAC engine more likely to wear than an ABC engine?
Answer:
Eight years ago I would have probably said yes. That is the conventional wisdom. In fact, I read not long ago in a racing forum a comment by a prominent racer stating just that. The opposite is true. That is why I make my premium engines with AAC liners. Do you remember how nice it was to just change out a piston ring every so often? Well, using an AAC engines is very much the same. We get engines that look like they have been through the Great War, and when torn down and measured, we find the AAC liner is like new. In most cases, all we have to do is fit you a new piston and you are right back to "good as new". It saves you about 1/2 the cost of rebuilding.
The secret of AAC lies in the increased heat stability of the aluminum vs. the brass. With chrome on the liner you do not get wear in either case. What you get is warping of the top part of the brass liner due to heat and stress. The brass, when overheated, tends to "bell mouth" and loose its taper. The aluminum does not do that. About the only thing that will hurt the AAC liners is FOD (foreign object damage). Keep your engine and runway clean!
