happyal

Hi,

I've got a Rossi 40 in the nose of one of my planes and I need some advice on setting it up. It is running a bit rich at the low end, which I hope to be able to cure this weekend.

Anyway it's on a Pattern style plane with a pipe, running 10% Nitro, turning a 10 x 7 prop at about 14,500 rpm, which to me seems a little low? Is this about right for this engine on this prop?

What should I be using Prop and Nitro wise? I'm thinking about changing the pipe as the one that it on it looks homemade and leaking air pressure, any advice on pipes? I've looked at JustEngines purple pipes.

What do you guys think?

Shok

My Feedback: (28)

if it's anything like my Rossi .53, you need to be running 5% nitro, a cold plug, and I don't like to run anything bigger than an 8X7.5 pylon prop.

splatt

The rossi 40 lives for RPM. Find the prop that will give you upper 15's to lower 16's on the ground properly tuned and it will unload to 17 + in the air. We used them for Q500 and ran 9x7.5 wooden pylon props , good luck

happyal

Thanks,

I'm worried about the size of the plane body it's on. With a 9 something prop it doesn't clear the body by that much, will it still fly the plane OK?

PS I got it to prop hang with the 10 x 7 , I just love this engine

bob27s

My Feedback: (19)

measure you installed pipe length.... from the glow plug to the divergent (Fat) section of the pipe. Let me know what that is.

Your top end RPM is determined by the pipe. It provides boost, but it also works as a governor. Even if you put a smaller prop on it, the RPM will increase, but the pipe will try to keep it at the RPM it is tuned at... or will simply provide no boost.

Sounds as if the pipe is set a bit too long for the prop you are running. That will give you the rich idle and sometimes unpredictable midrange. Try keeping the prop, and shortening the pipe another 1/4".

splatt

Just drop down to a 10-5 or a 10-6. If your engine has no signs of over heating maybe stick with what you got and adjust the low side needle to fix the low RPM problem

Skribnod

Hey flashman , I'm running a the short pipe from morris hobbies and a 9.75 x5 prop and getting 16,800 static with 15% nitro (coolpower). I have had over 75 flights on this engine in a world models T-34 and it really moves !! I did purchase a prop variety kit from morris hobbies but found that the above prop tweaked the best. Not a problem with the engine yet. I actually own 2 MVVS .49 with short pipes and they can really beat the crap out of the rossi. For my money from now on its gonna be the mvvs all the way.

FlooredCOBRA

I have 3 MVVS engines myself. All or them run really strong and are very easy to tune.

I love the instantanous throttle repsonce out of them.

happyal

Hi,

Sorry haven't measured the pipe yet, I will do this week.

I did get the carb set right, nice ideal and smoth throttle all the way to max revs, which have increased to 15,000 on the ground with the 10 x 7 prop.

I have bought some smaller props for it too, but not fitted them yet, will do that also this week.

Sounds so good in the air, low passes at full throttle in front of you with the engine screaming are the bizz this is what I started in this hoby for.

I've looked at the MVVS Engines and they look really good, Next time I'm buying an engine I will look at these closly, do they rev as much as the Rossi? I can't go back to a lower revving engine, evan if they do have more power.

Skribnod

Yes they do rev as high as a rossi. Actually you can get them a tad higher with a tuned pipe and the right prop. Rossi's are kinda finicky on prop selection and the mvvs I own seem to like a variety of props.

happyal

HI,
I've messured the pipe from the Carb to the large bulge on the pipe and it's 37cm.

I've also been trying difffernet props. I've found that a 9 * 6 flys the plane best and it tacho's at 17,200 on the ground. Bad news is that I trashed that prop on a landing [&o]

I've taken some pics which I'll put on tonight. I've got another problem that I hope some one can point me in right.

The screws which keep the exchast in place keep coming out, I've tried Lock Tight but it's no good. I think that either I'll have to fill those holes with some sort of glue or tap them out to a bigger size. Has anyone else had this problem, what did you do?

It's great fun flying this plane

MyWay

15000 rpm with a 10/7 prop on a 40 size engine is very good. A mvvs 40 will not achieve this. I would put the mvvs 49 in the lowest power catagory for 50 size engines. To name a few, webra 50, rossi 53, irvine53, k&b 48, and probably the best, the jett 50. When making engine comparisons between a 40 size and a 50 size or a 50 size to a 60 size its like comparing apples to oranges.

happyal

HI,

Updated my Gallery to add some pictures of my Pattern plane with the Rossi installed.

P. Johnson

My Feedback: (1)

All of my experience with a Rossi 40 was on a Q-500, i prefered to run the Rev-up pylon series props. 8 3/4 x7 seemed to be my prop pf choice and could get 17500 on most any day running 15% nitro. the combonation was great for a light aircraft. Rossi's love to turn RPM, the more the better !
Peter