Now what are you up too?;)

Piston orientation
 

Hi guys, I pulled apart my evoII and forgot to note the direction of the piston. Does the longer side of the piston belong on the exhaust side or should it be situated on the intake side?

Thanks,

Doy.

Re: Piston orientation
 

Longer side of skirt towards the exhaust

AFM

Re: Re: Piston orientation
 

Thanks AFM! Can always count on you for a speedy reply:D

ports
 

Hi Guys

What's the difference between a 5 port and a 3 port engine? Will having a 5 port engine only allow you to join the A-main race and not the B-main race? I know the races for Nitro GP Foam have A and B classes. Im planning to get a 5 or 3 port Sirio Evo2.

What type of engine crankshaft should I be getting, an SG?(is SG and standard shaft the same?) or a threaded? I'll be fitting it to an R40 or a V1RRR.


thanks............

Re: ports
 

Difference is implicit...5 port engines have 4 transfer ports and 1 boost port....3 port engines have 2 transfer ports and 1 boost port. And official IFMAR, ROAR and EFRA races are run with 3 port engines. Some countries do have an open class for 5 port engines.
In any case getting on to an A main or B main depends on your driving skills and how fast you are.
Check your country and club rules to see what class do they run, and make your decision depending on that.
You need an SG shaft for either car, not a threaded. Sirio engines with threaded shafts are designated with "AF" at the end of model number. For example:

S12 TRP E is 3 port SG shaft EFRA spec ABC (Brass sleeve)
S12 TRP I is 3 port SG sahft IFMAR spec ABC (Brass sleeve)
S12 TRP AF is 3 port threaded shaft ABC
If they additionaly have the PRO designation it comes with AAC piston/sleeve set (Aluminum sleeve)

S12 TUP is 5 port SG shaft ABC
S12 TUP PRO is 5 port SG shaft AAC
S12 TUP AF is 5 port threaded shaft

AFM

Does anyone know why the Sirios at the 1/10 Worlds are so dominant? Are the new versions? They shouldn't have this much of an advantage over the novarossi motors.

It was a question of time. The evolution of Sirio engines has been steady ever since the pre-worlds, which they won, and have been working with Kyosho to win this Championship.
They have cleared all the "bugs with AAC sleeve/piston combination, and having Mauro Collari working on his own version of Sirios have made them get a little edge over Nova based engines.
For the Worlds Andrea Rossi has taken a special WC Edition Sirio Evo2, that will come on sale later this year.

AFM

evo 2 3p running temp
 

i asked before but it seems as if my motor is running hotter than it should for the speed i am getting from it. what is the highest temp i should see out of this motor and not be worried? i was running about 260 270 and i was feeling very slugish on the back strech at my track, what should do with my settings, go back to the general settings and then tweak them or what, i cant afford to cook this motor, i still have compression and it runs all day, just too hot for me, my other competition at the track are running 180 to 225 and going just as fast if not faster the guy with the 180 temp has a sirio trp 3 p .

Re: evo 2 3p running temp
 

250°F should be a safe allround temp, but Sirios love to run on the hot side , so 260°F is not uncommon.
These engines work best with their own pipe, which I think can't be found in the USA, but they also run great with the Yokomo M.Mileke pipe, and the Mugen P01002 pipe.
You might wan't to check your gearing to be able to keep up with the fastest guys at your track. What are they using??? Sirios work great with shorter gearing to be able to rev up tp their pówer band.

AFM

What car, pipe,and plug are you running yur motor with? What about gearing track length and ambient temp?

I'm running a Mugen MTX 3 Prospec on Rubber Tires Class, with a Sirio Collari Modified AAC IFMAR engine with 0.20mm head shim, and O'Donnell 077 std. plug. Running a Mugen P01002 pipe (until I get my Sirio Pipe from Europe). Our track is 320mts total lenght with 55mts main straight, and lots of techical turns on the inside.
My gearing is 21/59 first gear and 25/54 second gear (0.8 pitch).
Our track is at sea level and ambient temperature ranges from 15°C in winter to 27°C in summer, with 80 to 90% humidity.

AFM

Forgot to tell you I run Byron Fuel at 20% Nitro

AFM

I'm sorry, I was asking gentleman81. It's good to know your info though.

its a small parking lot track with a 150 ft straight way and about 300- 400 total track distance, i am running odonnel 20percent , a rdlogics turbo 2 pipe and ofna turbo plug. track temps were about 70-80deg last race, i race one race all day at about 200deg but it was hotter that day. how much does the temp effect how that motor will run hot? mtx3