Go to the following thread (Shim Tuning), you'll find the answer there.

http://www.rctech.net/forum/showthre...threadid=27775

Good luck
AFM

Very early Sirio carbs didn't have the mid range or jet needle adjustment, only had high and low needle adjustment.

AFM

How does the Sirio compare too a Nova based engine for tuning? I have a Rs12 S3 Jp looking for an alternative. I have been told RB's are hard to tune, specifically the Evo 2 model? Akso what is the connection betwwen Collari. Picco & Sirio? I know Collari are based on Picco, is it the same for Sirio or are they nova based?


Sn

The latest model from Sirio, the S12TRP "Evo2" is comparable in performance to the latest Nova based engines, it has a killer top end and is very easy to tune, very stable, and withstands high temps easily. I have one, and I'm very satisfied with it. It delivers its power at a higher powerband than the nova based engines, but when properly geared and with appropiate pipe IT IS A BOMB.

The L.Collari (Innotech)company started with modified Piccos, but now they work over Rossi engines.

The M.Collari company works over Sirio engines. Check this site:
werksracing.com/query.do?manufacturer=mcollari&main=engines&displa cement=12

AFM

Are the Sirio engines Nova based then?

No they aren't. Sirio engines are designed and manufactured by Star Motor Engineering. There is nothing in common with Nova based engines.
So resuming, you have:

Picco, and some derivative OFNA and Team Orion Wasp engines.

Novarossi, and all its derivatives (Rb, Novamega, Novamax, Mugen, JP, Rex, Top) and countless tuner engines.

Rossi

Sirio, and its derivative Tuned M.Collari version.

AFM

Any specs out yet for the M. Collari engines??

Check this site:

www.werksracing.com Under engines, look for M.Collari

AFM

I've checked but no specs on the site

Since i own a Sirio S12TRP "Evo2", and the base for the M.Collari engine is that one, I can tell you that my engine has 1.5hp@41,000rpm, so expect the same on the M.Collari, but probably on a different power band. It all depends on how it's been moded. Anyway my engine is ballistic.
AFM

afm:

Does Collari do a motor yet based on the Evo 2 spec? If so what is the model?

SN

Lets clarify:
A Sirio Evo2 is actually a factory "tuned" Sirio with factory mods on induction timing and ports, and better bearings and larger cooling head. You see OEM's are trying to cut business from private tuners, so they are selling OEM mildly modified engines.

The M.Collari engine is a moded Sirio by Mauro Collari with his own approach and technics.

Your other option would be a Murnan Modified Sirio, which by the way does Barry Baker's engines. You can see his web site at
www.murnanmodified.5u.com
The only way of comparing them would be actual track experience or a Dino shootout between the three by RC Nitro Magazine.
AFM

Just broke in my sirio .21 for my buggy and the thing is wicked fast. I've got the engine temping at 210-230 and its still fast. There is one thing that questions me still. I did the adjustment on both my stop idle screw and radio. The thing im noticing about this sirio is the throttle response is sensative. When I hit 1/2 throttle, the engine sounds like it's maxed out. And when I hit full throttle, it sounds the same with the same speed at 1/2 throttle ??? Thx guys for you input.

Try to adjust the throttle end point on your radio.

im planning on getting a G4 to run this summer on our local track its a small track probably 120x60

im wondering if the new evo 2 engine would be OK or do you guys think because of the g4's lower gear ratio and the small track size if i should go with something else

ive been told the novarossi x12 is a great choice but i dont really want to spend that kind of money unless i have to

are there any plans maybe for a sirio engine aimed at small tracks?

i had a sirio modded by smeltz in my mtx3 and it was extremely fast i noticed that it was effected by the pipe quite abit and that it seemed to run more consistent with a novarossi carb

if i do get a sirio evo 2 what pipe and header would you guys recommend from rdlogics they have alot of different options like turbo and regular pipes and outlaw and legal im thinking regular outlaw but i wanna know what you guys think