My Dad gave me a new Rossi he had trouble with years ago trying to break it in. Never been flown, just ran on the stand briefly.
My question is does anyone have any leads on gaskets and parts for this engine?
Also does anyone remember how to tune and set this engine up in a Byron fan? Any tricks or special considerations?
I have the stock black Rossi pipe and a BVM remote needle and this will go in a Byron F-16.

Any Slimer DF help would be appreciated, lol. This F-16 will be converted to turbine with a P-70 if this doesn't work out but I want to give this a chance to work first. Its an upgrade from the existing 60 size engine which didn't work well with this plane when it belonged to a friend of mine.

Fun project, thanks for any assistance.

Chris,

You are taxing my memory, but I do recall having one of those setup's myself back in the early 90's. This is what I recall;
- Use a fuel mix with 20% oil, and 15 - 20% nitro.
- To start setting up the carb, take a length of tubing and attach to the fuel line nipple on the carb. Close both needles; set the carb barrel to open a little as if at idle, now blow into the tubing and open the idle needle 1 and 1/2 turns from where you can first feel you are starting to blow through. (This is important as a tightly closed needle is not always the same position as where air is closed off - sometimes the needle need to be opened quite a bit before air start to get thought. You want to have the 1 and 1/2 tuns from that point). Now do the same with the main needle, but open it 2 turns - however, this is done while you have the carb barrel completely open.
- I would recommend on-board glow which you can switch from a separate channel. JOMAR in Canada sells a good unit. I use to use this as and when I wanted to have insurance that the engine will not die. ( The usual unit working with the throttle stick are no good as these engines used huge fuel volumes and could easily flood the engine when throttled up - the throttle unit switched off too quickly and did not always get to help burn the influx of fuel).
- I assume you have a long wand to start the engine with - good idea to fit a spinner on the front of the fan/engine and a common electric starter cone on the end of the wand, unless you actually have a wand with one way bearing (like BVM used).
- OK, let's now prime and start the engine. Once running, you want get the engine running reliably at full throttle without getting the engine making a four stroking sound. This will mean that you adjust the main needle 1/4 turn either richer (out) or leaner (in) as required. These engines are high reving and don't like to run too rich. Now the most important setting - the idle side and midrange. Throttle back the engine and set the idle to a fairly fast idle - the aim is to get an idle which does not produce enough forward thrust on the airframe and be reliable enough to idle for at least 90 seconds before being throttled up and the engine not stopping. The midrange is a combination of the two needles and will require some experimentation with both whilst running the carb at half open. I would first experiment with the idle needle, but with very small increments of needle adjustment. It no change, return the idle needle to the previous position and go to experiment on the main needle.
- At both idle and full throttle, when switching on the glow - if the rpm increases, the mixture is on the rich side. Try to get this situation, but not too much increase in rpm. If you do this and the rpm do not increase, you could be too lean and I would suggest going slightly richer. You want to try and get the engine running without glow and only use it for take-off, aerobatics and landing.

A few things to remember - these engines use a lot of fuel( so use an external start and taxi tank), they sound angry, they don't like to idle too low and slow, they don't want to be too rich. Unfortunately after all that, they are not as reliable as a turbine, so expect a few dead stick landings.

Good luck,

Jan

Thanks Jan, thats great info and a good starting point. I helped my friend with the re-maiden of this plane on the 61 thats in it. I tuned it and it ran great but just not enough power. Im looking forward to trying this Rossi out after I rebuild it with fresh gaskets and o-rings.
I do remember my Dad running this engine many many years ago and it was one pissed off unit! Luckily its been in a box untouched and still turns however I'm going to take it apart very carefully and save what I can as templates just in case.

Anyone have any leads on new old stock parts?

I have always heard that the .91s needed an OS Carb to be truly reliable. Check with http://www.rossienginesusa.us/

Although I am a huge fan of having fun and doing stuff just to do it, an old Rossi engine to use as a ducted fan?

I say, save yourself the trouble and just buy that P-70 already.

Whatever you do though, have fun doing it!

The Rossi 91's were very problematic and often cut out when they got hot mid-flight. If you want to do a DF pitch the Rossi and get an OS91DF.

Just remember, doesnt matter how angry you make it sound, or how good the engine runs, the Byron F-16 will ALWAY feel underpowered. It just does. The .91 was a big improvement over the .65 but it is still a dog.

Lol, not a lot of optimism on this one heh? Well luckily I have the P-70 on hand so perhaps skipping this Rossi experiment is the best choice from what I gathering here.
This conversion will have to wait until my friend and I have time to laser cut the new formers and strengthen up the plane. I have to add brakes and retracts too. Not a big project but time consuming for sure.

Thanks for the Rossi link Im going to check on that.

My Rossi .81 ran well on 5% nitro and was underpowered compared to the OS .91. That being said, I never had any flame out issues with it, just wasn't as fast as the OS .91.

Good luck.

I had a .91 in mine and it was not underpowered. Was it fast, no, of course not. I could take off of thick grass in about 200 feet and climb out a pretty good angle, certainly never struggled. Loops and verticals of 2-300 feet were no problem. It does an awesome tail slide!
Do NOT use the byrons fuel system. It would not flow enough fuel to richen the OS 91 up.
I sold mind after a several flight since I did not like it. It did not fly all that well in my opinion. It was easy to fly, but it was not very fun to fly. I HATED the throttle-pitch coupling issues that mine had. Throttling up caused a significant pitch down for some reason, and coming off the throttle caused a pitch up. No other DF that I have flown has even done this.