Now that's a statement I would expect from a Sirio sales guy

I take it, you like it.

maybe the xxx is a better one!

yes there great

Stefan,

I've recently run the Ninja .12, Picco Evo II and III Red Dots, and EVO IV IDM in my new Kyosho RRR Evo 2. I decided to try the Sirio Evo 4 Sti and it is by far the best engine I've ever run. It amazes me how well the engine holds a tune and the broad power band that it has. Has torque everywhere. At our local track some of the other racers are running Max Power and Novarossi motors and I haven't had any problems keeping up with them with my RRR Evo 2. We race locally every weekend and I haven't even had to readjust my carb settings in the last 3 weeks. I was so impressed with the motor that I've put another one on layaway and I don't even have half a gallon through this one. I may even be looking into purchasing the new Sirio XXX. Hope you enjoy your Evo 4 Sti as much as I do.

Regards,
Speyederjedi

The size of you pinhead "KEMPNER"

Stop modding your motors and you won't have to replace parts.

Are you rebuilding your Sirio so you can keep up with me?

Have you fixed your Broke Back NT1?

Just Kidding, See you at the track soon.

D

Wants to take a detailed look into the innards of this? (look at the attachment)...

More to come in the next hours.

Hey Alfonso, where are the pics. We are waiting!!!

A friend did take over a pinched one. He has experiences with the NR Plus-2 pakage, JP Stock, Vega (=crap), JL evo-3 and now the Sirio EVO4

From all engines he loves to drive with the Sirio.

Ok. Ok... Here are the photos. Sorry for the late in posting but been quite busy during the weekend.

Some photos here.

First photo: This is how looks the last Italian weapon logo (Sorry... Vin Diesel not included).
Second photo: This is the look of the new underhead. Completely new sealing. This time, underhead doesn't insert on the sleeve. Very small squish band and hemi chamber.
Third photo: Side view of the crankcase with the sleeve and the underhead installed.

First photo: A look on the inside of the crankcase. Ceramic bearings all two (Main & Front). Looks nice.
Second photo: A look of the crankcase with the sleeve installed. The holes for lightening are very noticeable here.
Third photo: Piston at their TDC without the sleeve installed (sorry, pinch doesn't allowed me to make the photo with the sleeve, but if my measurements will be correct. Almost zero deck here.

This time, let's take a look on the sleeve and crankshaft. But nothing funky there.

Sleeve doesn't go that far as the other STi versions went with radical cuts and slits on the sleeve.

Crankshaft looks good. A big tear on the counterweight and steep ramps on the front side of the counterweight.

More views of the crankshaft.

Carb is very similar (if not identical) to the EVO4 one. 3 needles (HSN, LSN, Idle) with adjustable spraybar (nice to see that adjustable spraybar is here to stay with us another time).

Nothing new on the pipe section. As was directed on previous versions, Sirio 2611 is the one to match the engine.

Haven't measured it, but the conrod seems to be like the EVO4 one. Need to check it.

Note: Is the second engine from a very long list that is subjected to a teardown, inspection and cleaning and the cotton swabs used to pick all the dirt and debriss went clean (no dirt inside during inspection. This deserves a Bravo in this aspect). The other was a Jim Hottinger modded .21 unit. That doesn't mean you might not disassemble and check for dirt your units. Mine came clean, YMMV here.

Interesting shape of the combustion, some Singh grooves will work on this.

Saw the photos and missed to say that shim that gives correct compression ratio is there (aluminium one). Maybe is hard to see but is there.

Singh grooves could led to a potential loss of compression that could not be completely corrected (think that piston goes almost 0 deck on the sleeve) so you cannot compensate it lowering the combustion chamber.

From the pics it looks like you could groove it you would just have to be very careful not to let the groove get into the area where the shims go.