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-   -   Rossi engine info? (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/9055537-rossi-engine-info.html)

Quikturn 08-29-2009 10:36 PM

Rossi engine info?
 
Does anyone know where I can find information on Rossi engines? Some of the power specs I see are amazing if they're true.

Also, are these good engines? I'm looking at an older 60 size but don't know if it's as good as a new AXE Rossi 60 long stroke.

freakingfast 08-29-2009 11:47 PM

RE: Rossi engine info?
 
Very good engines, Optimistic power ratings, Feed the them low nitro.
This may be the last of them with Nelson mufflers.

http://shop.vendio.com/RossiEnginesUSA/category/1/

combatpigg 08-30-2009 12:35 AM

RE: Rossi engine info?
 
It looks like the Rossi engines with the real "eye popping" performance claims are the car engines. ILJ has shown that these engines in the .12-.21 sizes can be married to purpose built speed planes with great results. If one of these engines is bolted to anything less than the ideal plane with the ideal prop, then the results will be very disappointing.

Iflyglow 08-30-2009 10:05 AM

RE: Rossi engine info?
 
Only car engines have eye opening performance! It looks to me like some of the .61's are rated @ 3.00 hp at 18,000 rpm to me.;)

jaka 08-30-2009 11:04 AM

RE: Rossi engine info?
 
Hi!
When you look at the hp ratings you must also look at the rpm.
3hp at 18000 (must be a .60 two stroke!) and do you know what prop they used..?
Well, to obtain 18000 rpm they used a very small prop , like a 9x6 or 9x7. -Do you think this small prop could be used to fly a sport model well??? Well not that particularly good, a much better prop would be a 11x7,5 , 12x6 or 13x5. Wonder how many hp that engine deliver at those props at 10000-13000rpm ..? Well not that much...Say around 1,5 hp at best.

Soo! The thing is to understand those hp ratings correctly.
OS engines, or any other engine, are also capable of high hp ratings provided you prop the engines right !

dhal22 08-30-2009 01:01 PM

RE: Rossi engine info?
 
this is the speed forum. a lot of engines here run 9 x something props. you're not going to get a lot of speed running 13" props on a .61.

Iflyglow 08-30-2009 04:43 PM

RE: Rossi engine info?
 

ORIGINAL: jaka

Hi!
When you look at the hp ratings you must also look at the rpm.
3hp at 18000 (must be a .60 two stroke!) and do you know what prop they used..?
Well, to obtain 18000 rpm they used a very small prop , like a 9x6 or 9x7. -Do you think this small prop could be used to fly a sport model well??? Well not that particularly good, a much better prop would be a 11x7,5 , 12x6 or 13x5. Wonder how many hp that engine deliver at those props at 10000-13000rpm ..? Well not that much...Say around 1,5 hp at best.

Soo! The thing is to understand those hp ratings correctly.
OS engines, or any other engine, are also capable of high hp ratings provided you prop the engines right !

Jaka,
This is the extreme speed thread, and those small props are what is used for speed, so yes the HP is possible. OS's at the same RPM create way less HP. There .75AX is rated 2.4 @ 15,000. Rossi's have allways been known for HIGH RPM.:D
My old ROSSI PIXI OUTLAW .12 Car engine was rated @ 2.5 HP at 43,000 and yes I said .12.:D:D:D

combatpigg 08-30-2009 04:57 PM

RE: Rossi engine info?
 
Sounds easy. 2.5 HP is enough to fly a 2 pound plane 170 mph, no problem.
Show us how it's done with that 43,000 rpm car engine.

proptop 08-30-2009 05:30 PM

RE: Rossi engine info?
 
The old saying "don't believe everything you read" holds true when it comes to Rossi's HP claims...:eek::D

sevans16 08-30-2009 05:44 PM

RE: Rossi engine info?
 
Here is a thread on the Rossi 60
http://www.rcuniverse.com/forum/m_54...tm.htm#5471391

Rossi's are a real high rpm engine and they are simply amazing engines. I ran a Rossi 60 for a couple of years. Great engine!!
I am sure that the new ones are as good as the old ones?? I had the old one, a flying buddy brought back from overseas(he was in the Air Force). I did have to run 2 head shims to allow for 15% nitro.

http://shop.vendio.com/RossiEnginesUSA/

combatpigg 08-30-2009 08:06 PM

RE: Rossi engine info?
 
My Rossi .45 with the big black muffler is a great engine for turning big "3D" props, but it won't turn a 8x8 any faster than my OS.32.
It weighs a ton, also.

tIANci 08-30-2009 11:13 PM

RE: Rossi engine info?
 
I love my Rossi 45 and the Rossi 53 ... the 53 is soooooooo sweet! I love the idle, sounds like a thoroughbred engine ... mmmmmm ...

Quikturn 08-30-2009 11:28 PM

RE: Rossi engine info?
 
1 Attachment(s)
First of all, I appreciate everyone's input. This is great.

These engine manufacturers like to provide hp and rpm specs but they don't tell you how to duplicate these results. They have recommended sport/scale props that achieve an rpm much lower than at peak hp. If a Rossi 60 really has 3.0hp @18k rpm, then it should turn a bigger or higher pitch prop than an OS 61 SF Pumped rated at 2hp @ 16k rpm to achieve those numbers. Right?

I have yet to hold a Rossi 60 and compare it to an OS 61 SF-P but the OS has a large carb on that engine. To me, a bigger carb means more fuel and air to mix, thus more power.
Pictured, I have a 61 FX and a 61 SF Pumped engine. Notice the size difference in the carbs? Again, the 61 SF-P has 2.0hp @ 16k rpm and the 61 FX is 1.9hp @ 16k rpm. That make sense to me. For Rossi to boast more power just makes me skeptical.


combatpigg 08-30-2009 11:47 PM

RE: Rossi engine info?
 
Look up how to derive HP on Wikipedia. Last time I looked there were 12 different ways HP can be defined. An engine mfg can use whichever method that makes his product look better. If the stated figures aren't qualified with a prop size.........................
It has been shown at this forum by ILJ that the ultra high rpm, low torque car engines can be very effective speed plane engines.

Switch_639 08-31-2009 12:57 AM

RE: Rossi engine info?
 
I have the R65 Rossi engine... also looking at going fast... the manufacturers tell me that 11x7 or 11x8 will get me up to 16K RPM which is where the peak power lies but I want the RPM for speed... some have said that the engine will actually start to lose speed when getting too much revs... when does the power start dropping going beyond a certain RPM? cause If I can keep the RPM to around not more than 17.5K in air that shouldn't happen...

combatpigg 08-31-2009 02:25 AM

RE: Rossi engine info?
 
Take my earlier example about 6 posts back. The Rossi .45 turns a big prop very well, but it can't turn a small speed prop any better than an engine that is only 2/3rds it's size and weight. There is something going on that gives you diminishing returns when you try to rev it past about 15-16,000. The engine does what it was sold as [a 3D engine with great throttle response] very well.
Some engines are more versatile, like the OS .15 and .32...some are more specialized.

SpeedBoy 08-31-2009 03:14 AM

RE: Rossi engine info?
 
I have seen a Rossi .53 doing something that any Jett .50 has been able to do yet [X(] and that's enough to me to consider it a good engine . :D:)[&:][>:] and this one too [8D]. LOL

Switch_639 08-31-2009 05:15 AM

RE: Rossi engine info?
 
my peak power is at 17K RPM... but thats not my worry... at what RPMS will the power drop and will I start losing speed?

Quikturn 08-31-2009 08:29 AM

RE: Rossi engine info?
 
I think what we're all talking about is a power curve on each engine. Perhaps when a manufacturer gives a hp/rpm figure for an engine, that would be the best it can do. So it would be unwise to prop or tune (tuned pipe) an engine to to turn at 18k rpm when it was designed for max hp at 16k rpm.

Quikturn 08-31-2009 08:34 AM

RE: Rossi engine info?
 
Also, what is not discussed is propeller efficiency. A prop spinning too fast can produce less trust.

Switch_639 08-31-2009 08:45 AM

RE: Rossi engine info?
 
thats why I am gonna use a Carbon prop... pricey but most efficient from what I heard...

RCER88 08-31-2009 09:38 AM

RE: Rossi engine info?
 
Hi guys

I run a ton of Rossi engines 45's and 61's. The 45's I run a 10x6 or 10x7 using the mini pipe muffler, they crank about 14k on the ground and scream in the air. the 61 with a tuned pipe i run 11x6 or 11x7 and open up more in the air too. That is on low nitro 5% or less.

To get peak speed you might try a 9x9 prop might work on a 45 or a 10x10 on a 61. but watch the rpms you get too high of rpm the service life is greatly reduced and may self destruct or blow the connecting rod.

Yes it is true you get past the peak and power does fall off the sweet spot for the Rossi is about 14.5k on the ground in the air it will run up to the peak.

Tony

RCER88 08-31-2009 09:54 AM

RE: Rossi engine info?
 
hi

If you run a pumped motor you have a bigger carb as they do push more fuel. but just because the motor can push more fuel does not mean it has more power. Power is generated in the bearings, tolerances and flow inside the motor as well as the compression. As the rossi is an Italian made engine it is designed to run on low nitro as nitro fuel is not available in Europe. The tolerances are tighter in the rossi over the OS so it will generate more power. I pulled an OS 61 off a plane and replaced with a rossi 61 remarkable and really noticable difference. The rossi was superior running lower nitro fuel.

Tony

lfinney 08-31-2009 10:30 AM

RE: Rossi engine info?
 
the 3d rossi config has lower timing and different port count, the high rev engines have more sleeve port count and such, the biggest cork in the rossi 40-60 size engines is the carb size at a mere 8mm, the latest ones have 10mm throat size, external neck size is the same, i wouldnt worry for a second about rossi engine longevity, their bottom ends are legendary for a reason, the bearing size on the 40-53 are the size of asian 60-90 size engines.... os hyper 50 engines have bigger carbs, in the range of 10mm, the are run at 17-20 k SOP, their weakness is rear bearing failure and pistons blowing up at the ring land area from to lean of run or not enough ring end gap.... just tore down a friends hyper 50 OS , lemme see 70 dollar heatsink head, 70 ish for new ring and piston......plus rear bearing, presto you have the cost of a new hyper 50[:@][>:]

Switch_639 08-31-2009 10:54 AM

RE: Rossi engine info?
 
does losing power beyond peak rpm necessarily mean losing speed?


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