there are 3 difrent sirio 21 pr pro engines first is the older version s21pr pro 7 port aac. The lates relised version is the s21 pr pro evo2 7 ports aac. And the last is the s21 pr pro evo 2 sti 7 ports aac. The best way to tell them apart is the early s21pr pro engine had a black head and there was a second version of the sirio 21 pr pro with a blue head they had a 21 on the head and 21 on the side of the block but most important when you look at the crank it will only have one balancing plug in the bell. Were as the new s21pr pro evo2 and evo2 sti boath have blue heads the sti will have sti on the head above the exhaust port and it will have sti on the bell of the crank and 2 blancing weights in the crank bell and no 21 stamped in the side of the block. The s21pr pro evo2 engine will be the same minis the sti marks and slighty less work to port's and crank but outher than that they are the same. if you post a pic of the head and the block side on ill can tell you defently and send you all the part numbers you will need and were to get them from. Regards Jeremy.

There was also a s21pr 7 port "abc" engine this was an "alloy piston, brass liner, and crome inside the liner" version of the s21pr pro. When a sirio engine is coaded with a "pro" on the number on the box it should be aac "Alloy piston, Alloy liner, and crome inside the liner". Regards Jeremy.

which one did i get?
is it aac?
thanks jeremy

Hey twiggy you got none of them your model of sirio is unique to the limeted edition it is the sirio 21 wcr its almost the same as a s21pr pro but with a few major difrences. first is the liner exposed half way up the block for better cooling and weight saving its called integral aac liner. You should be able to see were the liner fins start and the crank case ends. It uses a 6 bolt config to hold the head down and 4 bolts to hold the liner inplace. by the way those 4 bolts under the head are imperial size not metric. don't use a 3mm hex key i think if i rember corectly its 2/32" of an inch hex key you need all the rest are metric. It also has a black hard smooth coating on the crank to prevent ware + the crank is dubble blanced. the stats for that engine are way up there with even the top engines now. collari won the 2003 worlds with that type of engine and then won agen in 2005 but with the gold head collari edition of the engine. Get a 2013 rb or sirio pipe and conical header to make even more power. Its very smooth power and out of this world rpms. just keep checking the bearings as the rpms the sirio engines pull is very hard on them. Best Regards Jeremy.

The collari version of that engine Twiggy was dynoed by a us rc mag and came in at a massive 3.03hp i missed the artical so i don't know what fuel or pipe they tested with but I'm confadant there is very litle if any difrence between the collari gt and the sirio wcr. Regards Jeremy.

This is the bad boy right here. I realise this is the older version but will the later parts still fit ? I am just trying to work out whether or not to do a P/S/R or chuck it on the junk pile . Where do we buy parts for these in Oz ? The distributors couldn't even tell me where to go shopping .......

Thanks
Aaron


Sirio SP21PRPRO On-Road
Size: .21 HP (bhp): 2.6 hp Bore: 16.35 mm Stroke: 16.65 mm Ports: 7 Weight: Not Available Crank: SG Construction: Other Displacement: 3.5 cc Type: On-Road Exhaust: Rear Carb: Slide RPM Range: 44,000 max Webpage: www.teamtrinity.com Est. Street Cost: Not Available

There may not be parts instock but you could try kelletts hobbies in sydney they are the inporter for sirio ph (02)96022333 ask for garry kellett and tell him i sent you he will look after you. Yes that is the earlest s21pr pro version Best Regards jeremy ps check your pm

Hey Guys, Received news today that top Kyosho racer Takaaki Shimo has left Sirio engines. He is now the 4th confirmed factory Kyosho driver to leave the Italian engine manufacturer, fueling the rumours further that the Kyosho / Sirio partnership is over.

http://www.redrc.net/2007/03/takaaki...-leaves-sirio/

I Have no idear why Mr Andra Rossi has let so many things slide for so long People who are exprenced with sirio engines know all about why this split is happening. I sill can not understand why it has gone this far. Regards Jeremy.

LOL I find it odd how a few team drivers leave, then people just asume that Kyosho and Sirio is spliting up.
Team drivers come and go. That is nothing different from any other race team / manufacture.

That's an interesting way of looking at it Tim.

Let's say that I own XYZ Nitro Engine Corp and I partner with you to sell my engines in your cars. We have a good relationship for many years and all my Team drivers use Kyoshos. Then one day, I let my Team drivers drive other cars - to the point that none of my Team drivers are driving Kyoshos anymore. And to top things off, my drivers are beating all of your guys at major events.

Do you actually think we're still going to be "best buds"?

What team members run, and what the company distributes are two different relationships. Look at Mark Pavidis, He runs Kyosho, O.S. and Pro Line. Just because Mark runs O.S. does not mean the relationship with Kyosho and Sirio is going to be effected. Now, low engine sales, that will affect the Sirio relationship.

All of these articals about team drivers going to another engine company does not mean the relationship with Kyosho and Sirio is strained in anyway. At least it has not affected Kyosho America. These are only rumors and here say. Kyosho has plenty of other drivers that run Sirio engines. .

Im sick of hearing the same rumors as well & I run Sirio now as well. I guess O.S. sales will be down as well

Is Ron Atomic still running sirio, because I know he is still on the o.s. web site for the .12tz

Tim you Hit it Right on the Head And this is were the problum lies. Sirio makes 2 types of engine's one for the public and a totaly difrent engine for there factory drivers. I can see you are an avid sirio supporter and I was very much like you for years. I would love to see sirio come back stronger than ever. But I think very very big changes must happen for sirio to return as a quality engine producer as they once were. Regards Jeremy.