Sirio Conrod
 

Hi,

I was wondering how many of you out there had problem with your Sirio Conrod. I'm running the Sirio .12 TRP PRo and after 6 months my conrod broke. My friends have a 3 port and after just 2 month it broke. Are the Sirio conrod not as strong as others or is this normal? Also I found replacement parts for them are very hard to get. I live in Australia and I normally order stuff from RC Mart or RC Model, but was told that they've been out of stock for about 8 months now.

Your feedback would be greatly appreciated.

Re: Sirio Conrod
 

As I personaly faced, a lot of Sirio conrods are broken. It is very questionable to make statement as why is that, but I can say from what I saw-cranck pin isn't hard enough and bronze they use on conrod isn't that right for this particular aplication. I can sugest them ( Sirio) to coat pin with chrome or make surface hardening with higher number.
Defenetly if conrod broken something is wrong. It can be worn out, but no broken.:nod:

I got into some serios for the first time the other day, (an anti trinity thing actually) what I saw was some serious machining steps at the bottom of the beam at the big end. It was cause for concern for me so I worked on that area some. Hopefully those will work out for the customers I built them for. I had heard of this before but I thought I had heard they had addressed this.

I'm curious.Precisely where did yours break??

Re: Re: Sirio Conrod
 

Agree with you 150% TG
My Sirio Evo2 after a gallon of fuel has developed an unsual wear between the crank pin and the conrod's big end. I've stoped using it and ordered a new conrod but...... i made a mistake not measuring pin dia and conrod bushing before break-in, so I don't know if only changing conrod is enough.
Do you know what are those stock diameters???
I love my Sirio Evo2, it is the fastest engine I've had so far, and has the new track record here, but..... it would be very expensive to keep it if I have to change conrods or cranks that often....buaahhhh!!!!!

Afm

Motorman, the conrod broke at the end that was holding onto the piston. It just cracked open. I'm not running the engine lean or anything like that. The conrod feel very weak. I wonder if there are any other conrod that would fit the sirio. I heard the Nova Carbs fit the Sirio, what about the conrod??

The sirio is a great engine in terms of peformance, but they need to sort out their reliability.

Just great! Sounds like I just bought a boat anchor. It's not like I have a couple hundred bucks to test my shreader with.:flaming:

Re: Sirio Conrod
 

Contact Max Tech Innovation they the Sirio Importer in OZ

TOLERANCES
 

Who knows what are the standard measurements for the
Sirio S12 crank pin and conrod large and small ends bushings???

What would be the maximum tolerance before changing conrod and/or crank???

Thanks in advance for help in this issue

AFM

Re: TOLERANCES
 

I will not bother my self till have tolerance more then .07-.08 mm.

Hi guys, for your records below is the official answer I got from the factory concerning conrod life for the Sirio S12. Also I did measurement to crank pin on a new stock engine and found that it has 4.428mm.
Hope it helps everybody
AFM

"The right play between crank pin and conrod bushing is 0,04 - 0,05 mm. I don't know if you're able to check it, but I suggest you change the conrod every 2-3 hours running.
The life of the conrod depends mainly on the fuel you use, as the lubrification and the right carburation keeps your engine running well for long time."

Regards,

ANDREA ROSSI
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Wow, normally that's ok but, this rod is $40!

I have seen here in Venezuela, from the experience of the local distributor, that the first batch of Sirio where excellent (piston/sleeve, conrod) but the new batch, i think that they call Evo2, is not the same. Main issue is the conrod. In most of the cases have a lot of play after 30 minutes of use and in some case even brokes. I see that this guys are using the same fuel, by the way, mixed by themselves and so sure that there is enough fuel, and before they did not have any problems. On the other hand, the factory claim that there is no problem at all with the materials. Seems to me that something has changed in the material or is just a "defective" conrod batch:weird:
Just my 2 cents

Paolo

Are there any conrods from novarossi engines that are compatible with the first batch of sirio 12 engines?

Unfortunately no. Different lenght and pins diameters.
AFM

Sirio rebuild
 

Hi I have recently rebuilt a sirio .12 after a conrod failure the bronze big end bush had totally disintergrated.
After measuring everything up I discovered the Big end journal was 0.06mm
out of round,I dont know if this was a factory problem or a result of the conrod failure.After looking around for a replacement conrod I decided to make my own as the originals dont seem able to cut it.
As Im an engineer I remachined the crankpin and made a new conrod with a steeper knifedge profile to give it more strength and also machined 1mm radius around the pin ends to reduce fatigue at that point.The new conrod is made from alloy tooling plate Light and strong.
So far its run great . :D