First off you know the engine we are talking about is an onroad engine? as far as parts go They would be very hard to find i would think no were would have a piston and liner combo instock except maby the factory maby. rods and bearings are as per normal sirio 21 just the racing versions of rear bearing and conrod. The engine will not like that fuel mix the 21 wcr is a stright out race engine and all sirio engine hate lots of oil. Also there is no need to run 30% nitro in this engine its plenty fast use 25% you will get better life and the paformance will be impressive to say the least. Exspect around 5 min run time from this engine same as most high end race 21 on-road engines. But the bigiest thing at the moment for you is fuel you need a better fuel a race brew and parts will probaly be very hard to get apart from bearings and conrods. Regards Jeremy.

Yes, I do know this is an on-road engine and I have it in a PRP XR8 (I'd much rather have a serpent!). Fuel wont be a problem I would just rather stick with having one fuel for all of my vehicles but oh well. The engine came with extra crank bearings and a con rod so I'm sure I'm set on that untill the sleeve wears out.

Thanks again for the info.

defnatly not you eill need to replace the conrod and bearings at the first hint of the bearings getting noisie and replace the conrod and piston pin and clip or clips when the conrod starts to get excessave play. Ive said it befor sirio piston and liners are very good the last a long time even the aac ones. You could run the 14% oil fuel but it will slow the engine down and make it run hotter. the oil mix in fuel can make a huge difrence to running temp qute ezaly 20 deg C form some oil mixes to outers. Just check the engine regulary for ware and condishion and clean and after run it. and tune it well and it will last a long time. Best Regards Jeremy.

Does anyone have the stock needle settings for the Sirio STI EVO3? Thanks.

can anyone assist me in define the difference between a long stroke and a short stroke engine? (in every angle) TQVM

i read somewhere that short stroke engines rev harder while longer stroke engines have more torque.

Bro..if you don't mind can u please direct me to this source?TQVM

short stroke = bore is larger then stroke say eg; bore 15mm stroke 13mm
square engine = bore and stroke are the same say eg; bore 14mm stroke 14mm
long stroke = bore smaller then stroke say eg; bore 13mm stroke 15mm

short stroke engines tend to give more RPM and less torque, long stroke engines tend to give slightly les RPM but more torque - this is just 2 stroke 411.

just in case you dont know i think this is how the bore/stroke relate, someone who knows for 100% certain can correct me if i'm wrong; the bore is the size of the sleeve that the piston pumps up and down in and the stroke is how far the piston moves from TDC to BDC in one revolotion.

the capacity of the engine is worked out by how much displacement the cylinder has from the top of the head button to the top of the piston when it is at BDC this measurement gives you a volume of the cylinder.

by changing the bore/stroke size they can create short/square/long stroke motor when you are restricted to a certain sized capacity.

TDC = piston @ 'top dead center'
BDC = piston @ 'bottom dead center'

hope this helps?

stroke is right
bore is the diameter of the sleeve

It's the internal diameter of the sleeve ;)

Questions on Sirio S12 SE Blue Head, Threaded Crank
 

I am trying to rebuild this but am struggling.

1. Can anyone provide me with a link to an exploded parts manual?
2. I pretty sure that the piston to sleeve clearances are poor, there is very little compression and no pinch when cold; I'm told should there be, is that right?
3. When cold, fuel bubbles out around the exhaust port when cranking by hand and it's easy to take it right over TDC with my finger on the flywheel. Are these signs of wear?
4. I can wobble the conrod slightly when I place it on the crank, is this worn too and if so, what can be done to fix it?
5. It runs at power but hates to idle; is this a sign of wear.
6. Where's the best place to buy spares?
7. Should I bother rebuilding, I don't mind the engineering but I also don't want to throw good money after bad.

Thanks

I just orderd an STI Evo 3 and wanted to know if I can use Novarossi plugs on it? Also whats the procedure for break-in on this engine?

Thanks.

comparing a Vr12plus and Sirio pipe into Sirio motor....
any big different between them ?

thanks ;)

Biggest difference is run time with the Skyline besting the Sirio. The Sirio pipe will keep revving at the top end of the rpm range but bottom to mid the Skyline has a lot more snap. IMHO the Skyline is a better pipe overall.

thanks for the advised....
guess Sirio pipe is more suitable on big track less techical wherelse skyline more suitable to small techical track...
hope i get it right... :smile:

i would stick to sirio plugs if you can get some.
to break it in, just use josh cyrul's break in method found at cefx.net

New Sirio .12 Evo3 Break In Problems
 

I have a new Sirio .12 Evo3 - model S12T3AF 3-port, Rear Exhaust, Rotary Carb.

The carb has 2 needles and a slow running speed screw.

1. There is NO DATA AT ALL on settings for this engine, not in the box, not on the Sirio web site - UNFORGIVEABLE.
2. The engine was SOOO tight that it made juddering scraping noises and could only be turned over using an Allen wrench even though I had placed oil in the engine - I actually filmed this in case it was an indicator of a bad engine.
3. I can only get the engine to start and run with the LSN out 0.5 to 1 turn which seems crazy low. The HSN is set to 2.5 turns.

The engine is difficult to start, cuts out easily and seems to be running VERY rich with smoke from the exhaust when running but it struggles to build up any rpm which I suspect is due to it still being ridiculously tight. Although I have about 4 tanks of fuel though it, it often gets locked at TDC when I have it on the starter box and I have to free it with an Allen wrench. I have been running it for 3-4 minutes at a time and temps never get over 200F. I make sure that it's at BDC when I let it cool down.

Anyone with suggestions or ideas on how to proceed, settings, etc?

how many tanks have you run through it?
on a bench youll need 2-3 tanks before touching the needles,or in a car 5-6 tanks , top end is usually extremely rich , in some cases ive had to turn the top end in 2-3 turns after run in process to get it close,
all motors are tight when new and the all make that tight sound for the first few tanks
ive had and use sirios and have never had a problem, there the best motor by far :D

I have 3 or 4 tanks through so far, I probably need to stick with a few more from what you say.

Thanks but what are the initial recommended settings for an EVO3?

Seems like I am worrying too much, I will stick with a few more tanks. My last Sirio which I picked up as part of a used package was sweet. I have a new OS CVR and it was nowhere near as tight as this Sirio at first.

Blown sv had some good points to keep in mind... First thing, is there a hobby shop in your area that you can go to for some 1 on1 help?? That's the first thing you should do. It's very important to never rush or do the wrong things while trying to break-in a motor... Sirio's are some of the fastest motors you can buy and the manuel goes through the break-in process step by step... One thing to have while breaking in a new motor is a hair dryer... Heat the motor up with the hair dryer and it'll be much easier to start up... Also, when the motor is new and the carb is set with the factory settings, the motor will and should be rich... ie... full of fuel... The extra fuel and oil will help the motor break in correctly and for the metals to Seat properly... If your motor should lock up, clear out the unused fuel and use a hair dryer to add you in starting the motor... Read the manuel from front to back... And break in the motor as per the Sirio manuel only. It may take up to 10-15 tanks of fuel before the motor starts to loosen's up if not more, and that's a good thing. You never want a motor that's broken in on the 5th tank... Again, take your time... Rushing things will only hurt your motor and for what??? $200.00 plus dollars is alot of money to throw away by doing the wrong things... Again, if there is a lhs near by, take it to them and get some help that way. You'll be able to figure things out much better with someone that know's what they are doing right there in front of you then chasing tips gathered on the internet... .02 and Good luck. :nod:

RC_Alan

I'm sure Tim Johnson of Kyosho USA, know's the base line settings and will get you going in the right direction... :nod:

RC_Alan

Thanks for all the help so far. I just ran another couple of tanks through and I do believe it's getting a wee bit looser but it's a pig to keep idling; if I increase the low speed needle it stalls, if I decrease the low speed needle, it stalls, if I increase the high speed needle it stalls, if I decrease the high speed needle, it stalls, that makes me wonder if I have the wrong plug in it. Alos the fact that anything over 1.5 turn out on the LSN and it won't run seems plain screwy to me. Reading the manual is great advice except that there really is no manual worth speaking of and what there is I have read - it has such gems in it as... "A PREVIOUS CARBURETTOR CHECK LET OBTAIN THE OPTIMUM CARBURATION BY A MINIMUM ROTATING OF BASE AND SPEED NEEDLES." (Sirio's capitalization, not mine). I have also checked out their web site and looked at the Kyosho web site - no joy. Kyosho/Sirio could do themselves a lot of good simply by getting someone to write them a reasonable,basic, English manual. One that includes such advanced topics as:

1. Recommended glow plugs
2. Needle settings to get you going

I currently have an OS P7 medium plug installed, obviously a turbo plug. Air temperatures here are currently in the low 70s F (low 20s C). There does not appear to be any fuel leaks around the plug. Any info on what others are using as a plug in this Sirio EVO3 engine would be useful.

I'm not trying to rush this but I also don't want to grope my way in the dark. Maybe this will end up being a great engine if I can find or figure out the right plug and right needles settings. Compared with the OS CVR that I just broke in (plug and great instructions supplied with engine), this Sirio is a pain and I'm not sure that I'd want to go through this much hassle again, however good a performer it might eventually be.

I'll see if I can reach that guy from Kyosho.

Just tried to call Kyosho USA but their answering system says they are closed for the Memorial Day holiday. Do you have a direct number or email for Tim Johnson?

Your best bet is to contact them tomorrow... Here's there web-link if you don't already have it... http://www.kyoshoamerica.com/contact.asp :cool:

RC_Alan

STI Evo 3 sti
 

Eng carb. problem
I ran the new motor maybe five times last summer and put away for next summer..
From the begining motor fires up no problem all morning and noon came around the motor sound like running too rich.. I think the low needle started to back out and could be the low jet needle o ring might be going bad...
is this normal ??
I heard some people have to rebuild the carburator all the time??:weird:
anybody experience this problem ?
what is the factory setting for the low and high needles?
and what plug number to use and good range temperture deg.

no

Use Josh Cyruls WOT break in method.

Raced my stock .12 STI in my RRR for the 3rd time today and I have to say, that I'm pretty disappointed with it's low end performance. I must be doing something wrong.

First two times I raced it, it spooled up real nice, but it wasn't very fast. In the infield between turns, it seemed to take too long to spool up. It could keep up with other cars on the 250' straight, so the top end seemed fine.

So for today's race, I added a 0.15mm shim (total 0.58mm "solder method" head clearance), switch to 30% nitro (up from 20%), ran a Sirio 6 turbo plug (versus 7), Skyline VR12 Plus pipe, stock RRR clutch setup with the nut at 1.5mm and stock gearing (1st Gear: 16/61 and 2nd Gear: 21/56). The car spooled up a little bit better, but still not fast enough between turns. So I switched to a 15T 1st gear pinion (only thing I had to work with), which gave the car some zip, but I'm still not laying down any serious power.

Any suggestions? What HSN/LSN settings are you guys running?

Thanks :)

What other glow plug brands can be use on sirio motor?

Ranier:

Much probably, your engine isn't fully broken-in. Mine STi's were a PITA to break in and one needed almost 10 litres to wake up (now is a monster).

I don't see nothing bad on your setup (well... those Skyline pipe... haven't tried, but the stock pipe does wonders, so I stick to it). Switch to a #7 Sirio plug, tried the #6 and #7 and prefeer by far the #7.

For what you're telling it sounds me that your engine isn't fully broken-in and it cannot stretch their legs too. You don't say how much fuel has been thru the P/S but.. looks very plausible to me that still lacks break-in. When broken in, the low end needle on the Sirios needs to be a tad leaner than on a Nova milll or similar, they love to go with the LSN quite lean (how much? easy... if you were adjusting a Nova, the adjustment should be 'too lean' - they need a different approach to adjusting the needles).

Only Sirios, the taper is different and they will leak if you use another plug.

10 liters!! (2.64 gallons) :eek: :lol:

Hmmm, let's see... 5 tanks WOT on the break-in bench, 5 tanks rich on the track - plus about 4 liters practicing and racing. Looks like I've got to up to 5 more liters to go. DRATS!!

Thanks for the help. :cool:

Thanks who sell sirio plus on line?

Around 5 litres, if your engine is one of the latest batches should be completely broken-in, mine were from early batches and came with a lot of pinch.

Do the changes I told you and give it a new try in some tanks, your engine is too rich on the LSN or isn't fully broken-in.

P.D: Just remember to take a look on the conrod! Nobody wants a serious carnage on those puppies. ;)

Lean the bottom end till you hear it ringing then back it off a little. You don't know the tuning limits of your motor until you reach them. If you are worried about your motor, always check the glow plug. It is the only fool proof method to making sure the engine is not lean. If the plug is a little bit dry in the center and wet on the outside then you have a perfectly tuned motor.

if it runs awesome on the track with no syptoms/sounds of too lean on bottom end whilst racing and comes in after 20~30 minute race singing daisy your all good. almost all the sirios at worlds were doing this, the factory guys motors just sounded too damn lean in comparison but they were making some serious power with no signs of fading during the qualifying etc granted they had andrea working on the tuning driver to there motors and who would know the motors better.

Thanks for all the advice guys. If I can't get any more speed by tuning the needles, I may try swapping out that 0.15mm shim for a 0.1mm shim and see if that helps.

Cheers :)

Just use the stock shimming, I forget the thickness but it is one copper and one silver shim, .04mm? I leave the shimming the same from 60 ft above sea level to 1000 ft and just tune the needles. So far there's only been one track that I've had to play with shimming.

Yes, stock is one copper and one sliver, which leaves a total head clearance of ~ 0.43mm. I'm pretty much at sea level, with the ocean only about 100 yards from the track. Humidty is usually very high here - much higher than in Cali.