Roadrunner1390

I have a Rossi 53 DF (never run) I think it is a little older 1990's. The instruction says that I need to run Rossi Fuel (go figure) or somthing with 15% Castor oil. The byron or other fuels have some castor but also say a synthetic blend. I dont want to cook the motor by using a modern fuel. I need help. I am going to run this with a prop on a diamond dust. I will be winding the piss out of it and want to hit 200+mph. So break in is important.


Email is [email protected]

ChuckAuger

My Feedback: (12)

Powermaster castor/synth blend in propped DF engine..looks new (well, except for the crash ) after maybe 100 flights. I used some extra castor for the first gallon (4oz/gallon) but straight 10% after that.

Roadrunner1390

Chuck, can you clairify on the oil to nitro for me. Also what prop should I start with on the 53 ?? I have been told that you need to go at least one prop size smaller for the DF than a regular R/C motor ??????

ChuckAuger

My Feedback: (12)

I use Powermaster 10%(nitro) in just about everything...I have run Rossi engines up past 20K with it no sweat. I just like to add a little castor to it when turning over 20K...just a little bit lean at these R's is a killer. I'm not sure what the % of castor is in Powermaster fuel, but I have used it almost exclusively for 18 years and am confident it is good fuel....I don't tend to putt around. The only reason I add castor to it is like I said...it will give a little extra protection (IMHO) when the RPM's are pretty high. I may be an idiot and use too much oil, but my engines all look very nice inside...it is just what I do.

On the VRDF that was in the DDust..I ran out of the extra castor fuel while at the field and used straight 10% Powermaster. The engine was just as happy...but it had a gallon (plus some...I started flying it on a partial...) of running on it by this time..I never went back and was running straight 10% Powermaster when it crashed.

Don't fret too much over fuel...I wouldn't run any straight synth fuel personally in a propped DF engine, but like I said I may be an idiot.

Rossi's are tough engines..but are not dependant on high nitro..10% will work fine if you let it turn up..ie don't bog it down with lots of prop...let it rev. If you try to run too much prop, you could go lower on nitro. And I take that you know how to set the pipe...

As for props...get some APC Q500 props..try the 8.75 X8.5 or 8.75 X9..something along those lines...depends on what you want to turn...I was using a 7.4X8.25...you just need to find something in the~8" dia/ 8~9" pitch range that lets your engine turn up to about 1~1.5K less than its rated max HP RPM, so when it unloads it will be running at max HP RPM...works for me.

Roadrunner1390

Thanks for the reply. I am planning to run Byron Fuel with 15% nitro and 20% total oil. I was told to add about 4 oz. of straight castor to one gallon. Do you think that is ok ??? Will the higher nitro hurt anything?? As for the prop, I am hesitently suprised that I need run such a small prop on a 53. I have no experience with DF motors. I am afraid of the piston launching out of the head !! But you know DF's better than I. I will use a 8x7 or so.

Roadrunner1390

Chuck, as for the pipe, I was given two with the motor. It was not clear what will work. The pipe I was going to use is 13 1/2" long and about 5" thick. It looks close to the pipe I run on my 46FX but a little fatter. Is it super critical to have an exact matched pipe ? The directions for the motor only indicate that the pipe should be 235 to 245 mm from the exhaust port to the fat part of the pipe. My concern was the pipe is a little small.

Roadrunner1390

CONT.

Chuck, as for tuning the pipe, I was going to cut the header so the length was to the directions (235 to 245 mm back) then check the RPM with a tach. Then move the pipe out a little on the sleeve and see what the rpm's do.

Well thanks for the help so far. Please get back to me on the above questions so I can break this puppy in. I am dying to get this in the dust !!!! [email protected]

C_Watkins

My Feedback: (10)

5" thick for a tuned pipe? Wow!

Roadrunner1390

Just looking through the threads. Hey it was you who told me to put 4 oz. of castor LOL . Talk to ya soon RR

Roadrunner1390

C. Watkins. Thanks for the wake up call. The pipe is about 1 3/4 thick. I put the tape around it and its 5" around !!! Give me a break I work midnights!!! LOL

Did you get that Chuck, its not 5" wide !! ( That would be one fat mother ------)

C_Watkins

My Feedback: (10)

Hey, I feel ya.
I'm coming off a midnight to noon'er here myself, in another hour.
got another one coming tonight, too

Yeah, I was thinking... 5". WOW. that's bigger than a turbine. hehe.

ChuckAuger

My Feedback: (12)

The length they gave you 235~245 mm is about 10" (damn..I hope jemo dont come in here and tell me it is really 9.6" LOL..inside joke!) This ought to be real close for a fan pipe length.

As for the small prop..don't worry..fans turn that high, you want to run a prop that is similar to the R's a fan would run..if you try to lug the engine down with a too large prop, it ain't gonna be happy. Let it rev! This is where it makes it's power! DF engines are not souped up versions of regular engines..the are just ported different to run in a higher RPM range. Let that work for you!

Byrons 15% will be pushing it IMHO as far as nitro is concerned (now I'm in trouble with PAINLESS..another inside) Unless you let your engine rev to the upper limits of its RPM range or run a couple of head shims, I don't see the need to run 15%...it will just make it harder to set and blow plugs in my experience...Rossi usually recommends low nitro fuel...

I'd try something different than a 8X7..if you are running 8" diameter, you ought to be able to run more than 7" of pitch...just remember that an inch of pitch will get you more speed than a couple thousand RPM...try to get at LEAST 8" of pitch...if you want to go fast and not just make noise...

Roadrunner1390

Thanks for all the help. I will try to find a fuel that has a lower nitro and a prop that is has more than 8 pitch. I will let you know how it went.

Roadrunner

MMallory

My Feedback: (1)

I agree on the fane engine. I would start with an 8x9 and maybe move to an 8x8. Set your pipe a little longer to start and shorten 1/4" at a time until you get the rpm drops a bit, then back up a 1/4" - 1/2". 5% max nitro on the Rossi unless you want to chase the needle all day.

Have fun,

Mark M.