Tiny Gas Engine
 

For those who was looking for small gas engine...here it is. I seen it at Toledo expo. Thanks Capt,n

Tiny Gas Engine
 

What company produces it? What size glo engine does it compare to in physical size?

Tiny Gas Engine
 

I saw one of these Campagnucci engines in a beat up old RC car in the LHS. Don't know how much power this little bugger puts put though.

Tiny Gas Engine
 

That engine is about a .40 size with electronic ignition and puts out about 1.35hp. Saw one in a LHS about two years ago.

More info at:
http://www.aerohobbies.com/Cars/Compagnucci.htm
http://www.mecoa.com/compagnucci/index2.htm#gasoline

Tiny Gas Engine
 

Thats 1.35 hp at 17,500 RPM!

Tiny Gas Engine
 

They also make engines for model Aircraft!!!

http://www.compagnucci.it/uk/frame_uk.htm

I wonder how much $$, I can't find it on the web-site. Maybe Mecoa can import one... if the price isn't to high.

Tiny Gas Engine
 

From what I could tell, it doesn't use needle bearings in the con rod. So it requires quite a bit of oil when running glow fuel and a good dose of oil with gasoline too.

I'm confused
 

Diablo - I haven't torn apart dozens of engines (only 5 or 6), but I've never seen bearings on the connecting rod. Even if it did have bearings there, shouldn't they be regular bearings or roller bearings? Needle bearings are tapered and seem inappropriate for the con rod. They're more appropriate for the front crankshaft bearing. Is that what you meant? I can't read Italian, but the exploded view of the Campagnucci engine looks like it has dual ball bearings (item #16 & 17).
http://www.compagnucci.it/immagini/new/motoxaereom.gifhttp://www.compagnucci.it/immagini/new/motoxaereom1.gif

Tiny Gas Engine
 

Needle bearings aren't tapered. Needle bearings are a type of roller bearing where the rollers are very long compared to the diameter of the rollers. Most 2 stroke gasoline engines use needle bearings on both ends of the connecting rod so they don't need a large amount of oil in the fuel to lubricate the bearings. Glow fuel engines use bronze bushings in the connecting rod and require 15-20% oil. Most gas engines can get by with 2-3% oil.

bearings
 

Needle bearings are not tapered. You may be thinking of tapered roller bearings?? Tapered bearings are used on some cars(ect) and have a adjustment. There may be various versions of each. RCIGN can explain it better. Captinjohn

Tiny Gas Engine
 

What you describe is what I've always known as roller bearings, and the tapered version of a roller bearing is what I've always known as a needle bearing (each roller is smaller on one end than the other). Sorry if I used the wrong terminology.

Since I've only torn apart glow engines, that explains why I've never seen bearings onthe con rod, just bushings.

They may have bearings on the con rod which doesn't show in the exploded view (the exploded views of glow don't show the bushings either). According to the website the gas ignition version of their engine uses That's a 20:1 mix after break-in. That's a bit higher than the average gas 2-stroke, but the average gas 2-stroke doesn't spin at 17,500 RPM.

Tiny Gas Engine
 

needle bearings are in many cases - uncaged and a typical application is in transmissons of cars -surrounding a shaft and inside a multiple gear (cluster)
roller bearings are typically - in a cage of some type .
typically, something holds the rollers apart.
Needle bearings in a retainer are the type of bearings used on model engine con rods .
this is a shell with the ends rolled around the ends of the needles and the exposed bearing surface is the inner portion .
hows that for useless info -

Tiny Gas Engine
 

OK - I've acknoledged my error - this isn't my area of expertise, and was using the wrong terminology.

That aside, what makes anyone say there aren't bearings on the con rod? For a con rod this small, they may be permanently integrated into the con rod ends.

If anyone reading this thread can read Italian, perhaps there's more info on the website you can translate for us, or can send an email to the manufacturers.

Has anyone found out the approximate price?

I'm a betting..
 

That they would be shown in the exploded view. Here is a shot from an old O&R Compact III showing the rod bearings.

http://www.pan-tex.net/usr/w/jwillia.../NeedleBrg.jpg

56 & 54 are the bearing groups. If it is any consolation, they are listed as "Roller Bearings" in the parts list :)

Bearing definitions
 

The Dictionary of Automotive Terms and Abbreviations lists Roller Bearings as: A bearing using a series of straight, cupped, or tapered rollers engaging an inner and outer ring or race.

Merriam-Webster Online defines roller bearings as: a bearing in which the journal rotates in peripheral contact with a number of rollers usually contained in a cage.
http://www.m-w.com/mw/art/rollerbe.gif
roller bearing: 1 outer race, 2 cage, 3 roller, 4 inner race

The Dictionary of Automotive Terms and Abbreviations also lists Needle Bearings as: a roller type bearing in which the many rollers have a very narrow diameter in relation to their length. The design makes them particularly useful in situations where there is limited space such as the rod bearings on some pistons. Also called "Quill-type bearing."

Merriam-Webster does not have a listing for needle bearings.

Bearings
 

I think tapered roller bearings can be used as a thrust bearing...not positive. I wish more model engines had rod bearings with needle type bearings...allowing less oil needed in fuel. Capt,n

Tiny Gas Engine
 

Timken- I recall pionered the tapered roller setups - long ago - they took up both radial and axial loads .
angled rollers are used in many apps - cars etc..

Re: Bearings
 

The only time I've ever seen them in use, was on a vertical axis which had to bear weight and still rotate. The front thrust bearing on our engines is a prime candidate for tapered roller bearings.

Tiny Gas Engine
 

A standard ball bearing will take about half of its rated load as a thrust bearing..The small amount of thrust our airplane engines make doesn't come anywhere near what the bearings could take..US and Quadra 35 and 41 engines have roller bearings, the thrust is taken up by a bronze thrust washer..Many small glow engines have bronze bushings and work just fine....I think someone at Fox engines once said there was no difference in the performance of the bushing engines, just less weight.....

Tiny Gas Engine
 

ball bearing much more simple and cheaper -
model engines - setup correctly - have a teensy bit of play in the bearing setups which allow the front bearing to take the thrust load - the rear bearing takes the radial load - on th chain saw stuff - there is still some slop needed - tho which bearing acually handles the axial load is unknown to me - and frankly
I don't care .

Tiny Gas Engine
 

So Rcign, based on your experience with gassers, would you be concerned about running this Compagnucci engine without roller bearings in the connecting rods?

Tiny Gas Engine
 

in a normal glow engine the front bearing carries no thrust load unless it's used in a pusher configuration or being slammed on with an electric starter, in normal use the rear bearing carries the thrust load. tapered roller bearings are used in pairs and require a spacer between the inner races, this would make a very expensive engine. standard ball bearings carry this small thrust load just fine.
the needle bearings on gas engine con-rods are the simple uncaged type that serve well at low engine speeds, for high speed glow engines a caged needle bearing would be needed but the main problem is finding room in anything smaller than a .90 .

dave

Tiny Gas Engine
 

Strato...Super Tigres have a bronze big end bearing, run well on gas with enough oil.....

Tiny Gas Engine
 

I've email Compagnucci in Italy for prices (aero version: CXR0036) but have no reply!

price
 

Try MECOA for prices....also. You may want to ask what is the best oil and ratio to fuel for these engines. I got a price on them by emailing, but do not want to give that data out. The company will ...and should quote prices. Capt,n

Tiny Gas Engine
 

I was just wondering for approximate costs, since MECOA doesn't post the price on their website. Was it less than 4 digits? What's the harm in posting the price unless you got a special "Dealer Price"?

Quoted from Compagnucci's website:That's a 20:1 mix after break-in. That's a bit higher than the average gas 2-stroke, but the average gas 2-stroke doesn't spin at 17,500 RPM.

Roller/needle bearings
 

If anyone in my age bracket can remember the Dooling 61 race car and conlroline speed engine of the late 40's and early 50's you may recall they had roller bearings on the con rod, both ends.
We experimented with 12- 15% Ucon synthetic oil. Still got beaten by the McCoy 60's!

Phil

Tiny Gas Engine
 

MANY years ago there was an OS with a roller bearing rod, maybe an 80, that had a rear intake......Seems like it had 2 glow plugs also...The OPS 30 single has one too..

Finally, a price!!!!!
 

I e-mailed MECOA last week and they finally responded. They explained that they are having e-mail difficulties and are slow to answer. :) :eek:

They said the Compagnucci aero version should be in soon and cost about $280.

Kinda spendy but very novel. I love novelties! Should make a great .40 size fun-fly motor (1.3+hp) and cheap to run and no glow plug and no castor oil and no continuous needle tuning and little clean up and smaller fuel tanks and $1.50/gal. fuel........... :cool:

MECOA (626) 359-9527

If anyone buys one, please let us all know how it runs.

Tiny Gas Engine
 

Just for info:
The term needle bearing does generally refer to roller bearings with long, skinny rollers. I don't know where the term came from, but I expect it has to do with the fact that The Torrington Company, who invented the drawn cup needle bearing (a story in itself), started out as the Excelsior Needle Company, making, you guessed it, sewing machine needles. Their expertise in forming wire, heat treating, etc., led them into making needle rollers, and from there, into the bearing buisness big time.

ball bearings
 

I visited the David-Andersen factory in Norway and talked to the owner Jan David-Andersen. At the time he had in production both a plain bearing and a ball bearing engine. He said the only thing better about the ball bearing engine was that it felt better to the modeler when he flipped the prop!

Re: Finally, a price!!!!!
 

That's better than my response time - I sent three back in April , and still haven't heard from them... :rolleyes:

Bearings
 

Having repaired about a Gazillion chain saws I would just add that many of them have/had needle bearings on the connecting rod (both ends) and ball bearings on each of the shaft ends. So far as I know our needle bearings were not tapered. Some others may have used them, that I don't know.

Tapered roller bearings
 

If a tapered roller bearing were used on a crankshaft, both ends would require it because you need two to oppose each other and be adjustable to have a preload on the bearings. If it were not adjustable for preload the rear bearing would get get hammered unmercifully as slack developed between the bearings.

Roller Bearings
 

In the early 1950's Fox came out with a .29R that was supposed to replace their plain bearing 29X in UC speed. It had roller bearings at the rear of the shaft and ball bearings at the front with a big square front intake. The old plain bearing 29X ran rings around it!

Phil

RE: Tiny Gas Engine
 

Does anyone have ordered and tried this engine? prop size, rpm? I was thinking in buying one.

RE: Tiny Gas Engine
 

I have a Webra SilverLine .61 that has needle bearings on both ends of the rod and a Merco .61 gasoline engine that does not. I have run the Merco many hours on a German synthetic lube with 4 oz of castor added. The rod bearings are as tight as when new.

RE: Tapered roller bearings
 

Hobbsy,
I think you may be incorrect when you say that you would need two taper roller bearings on a crankshaft, - one for the front and one at the rear. - could the crankpin take the bending stress applied by the preload required?

Two taper roller bearings, (opposing each other at the front, and a simple needle roller at the rear, or in the case of a cantilever crank, two at the front only, would be good.
This however, is theory, - In practice, space required, weight and cost would also come into play for production models.

( You may feel free to disagree of course, - but please say why! ;))

RE: ball bearings
 

There would not be a bending load on the rod, the tension would be on the crankshaft between the tapered roller bearings. I only mentioned the fact that it would take two opposed to each other in response to someones suggestion that one could be used for a thrust bearing. It would not be practical anyway since ball bearings do the job so well and the thrust load on them is a small fraction of their capacity.

RE: ball bearings
 

Hobbsy,
I didn't say a bending stress on the rod, I said the crankpin, - caused by the compressive force from the preload on the bearings.

With the two bearings on the front shaft, this won't happen.

(but we are discussing a taper roller at each side of the crankwebs here, - hence the problem).

PS, - I agree that ball bearings do a great job for our application, so what we are discussing is really only theory! ;)