Just found this..... Looks neat

http://www.rotomotor.cz/rotomotor/es...36-ROTO-85-FSI


Coming soon

Basic technical data:
* DISPLACEMENT 85 ccm
* BORE 39,5 mm
* WEIGHT 3 000 g
* PISTON ROD 4 × NEEDLE BEARING
* CRANK SHAFT 4 x BALL BEARING NSK
* INGNITION PROCESSOR ROTO
* FUELGAS + OIL MOTUL 710 1:40
* RPM 1000 - 5800
* 2 BLADE PROPELLER 25-26/10-12
* 3 BLADE PROPELLER 24/10-12
* STATIC EN. THRUST 13 kg



Manufacturing technology ROTO 85 FSI

• Crank case (kit) – it is rough-worked of the cast at the CNC milling cutter. After that it is covered or slashed with a special colour.
• Cylinder (roll) – it is made of one piece of dural with pressed insole from the mild-granular cast iron, it is sharpened and honed to the correct size.
• Piston – it is casted from silicon alloy with one sealing circle. The aparature for the bung 8 mm is honed.
• Piston rod – it is forging, which is completely worked. Two needle focuses are moulded into piston rod, it is made for the piston and cranked bung.
• Crank shaft – it is made of one piece of steel, it is cemented and hardened and it is completely sharpened.
• Back lid of the engine – it is worked casting, in which is hardened and sharpened rolled slide - valve layed.

http://www.youtube.com/watch?v=eJ7mhIPcNY8

That is a pretty awesome looking engine. Sounds pretty good too. Putting the carb at the rear also keeps the engine a lot more narrow in profile too. I wonder if they'll make a inline three cylinder version or not. I remember the Kolm 3 cylinder engine sounded very realistic when flying around in an airplane.

I wonder if they are coming out with a replacment for their 35cc single. most MFGs just use cylinders they have already when doing stuff like this. Roto has a 35cc single so two of these would make a 70. So did they make a larger bore to make up the extra 15cc?

never mind I see they make a 85cc opposed twin. lol i was hoping for a 42.5 cc single to compete with the OS 40FS

The new modified Roto 85 FSI inline are approaching me fast :-)

New and a lot better fuel distribution seems to solve bad midrange and also tricky adjustment. I will post testrun both mounted on ground and inflight test in my old Carden Yak before I will mount this beatiful engine in my Top Flite P47 Razorback

They have an inline 130 shown on their website. It does not have any data, so I guess it is in the works.

The 130 3 cylinder looks very cool.....would power my CY model / easytiger spitfire well. :-)
The 85cc might be a bit small for a quarter scale spitfire.... The price seems good, hope the 3 cylinder 130 is affordable.

https://www.youtube.com/watch?feature=player_detailpage&v=PUlX30EoNv8

I've been thinking about this engine for an Aeroworks P-51. Has anyone else tried this or done any research about how the two might fit together?!?!?

Considered one myself for a top flight p40.... I have been running of the opposing twin for over a year now with great success I am very happy with the engine

So much for doing things on an iPhone....

http://youtu.be/8ZSYAhFCbXc

It sounded real good what prop did you run?

The propeller is 25x12 Xoar

Here are my prop numbers
25x10 XOAR 5740 rpm
22x14 XOAR 6050 rpm
i also have run the 24x12 but have not tached it yet .... I'm going to try a 23x12 next and hope that it will get the speed I'm looking for. The 25x10 seemed to be the best for speed so far. I was actually dissapoonted with the 22x14 ... Not sure why it didn't deliver the speed I hoped for. If you haven't tried the 25x10 yet I would think it would be great on your yak