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RC engine horse power ratings

Old 08-12-2008, 04:38 PM
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mrbsltz
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Default RC engine horse power ratings

Is there a site somewhere where you can compare the HP ratings of different brand 2 and 4 stroke engines? Some companies advertise their HP, but other do not.
tks
Old 08-12-2008, 04:58 PM
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Ed_Moorman
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Default RE: RC engine horse power ratings

That's because horsepower for RC engines is totally meaningless. Comparing two engines or buying one based on horsepower is a waste of time & money.

Horsepower, given foot-pounds of torque, equals Torque times rpm divided by 5252. The torque curves have a fairly shallow slope so the big driver is rpm. Put on a small prop or a flywheel, lots of nitro and check the rpm. This will result in a lot of horsepower, but is useless for flying a plane with a normal size prop.

Manufacturer's horsepower rating may also be taken with an open exhaust, no muffler. There are no standards.
Old 08-12-2008, 05:07 PM
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Default RE: RC engine horse power ratings

ORIGINAL: mrbsltz

Is there a site somewhere where you can compare the HP ratings of different brand 2 and 4 stroke engines? Some companies advertise their HP, but other do not.
tks
No Clue!
Old 08-13-2008, 04:52 PM
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carrellh
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Default RE: RC engine horse power ratings

As already mentioned, RC company horsepower numbers are not very useful.
To mean anything at all, you'd need very specific info regarding the way the test was done.

You can browse or search the RCU "Tachometer Readings" forum to see what kind of numbers people are getting in the real world.
http://www.rcuniverse.com/forum/forumid_173/tt.htm
If a person really wanted to do the work, all of this data could be loaded to a database.
Old 08-14-2008, 09:53 AM
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CoosBayLumber
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Default RE: RC engine horse power ratings

I think Ed hit several of us between the eyes. I knew of the H.P. ratings, but how better to explain them too.

I know that just because you got a certain year model engine in thought, does not mean it will put out same in any of the follow-up years, for the Mfg'rs tend to get used to making it then sloppy.

I go to the AMA show in Ontario each January. A few of the Mfg'rs there say they are going to let loose with a new version of ____ the coming spring, and alter the whole line to match that. I see the very same dusty glow engines each year, and hear the same promise too.

Oops, time for a whole new model to come out again.



Wm.
Old 08-14-2008, 01:36 PM
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JohnBuckner
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Default RE: RC engine horse power ratings

Companys who are touting HP figures are gleefully living the marketeers phantasy and for those who make their purchasing decisions based on those figures, I have two prime lots on the golf course in Shangrila you are gonna love. Its a place where 15% is never over a buck a gallon and all .46's have 2.5 horsepower.
Old 08-14-2008, 06:28 PM
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Default RE: RC engine horse power ratings

I like " TORQUE " power myself !!! ENJOY !!! RED
Old 08-14-2008, 10:40 PM
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Default RE: RC engine horse power ratings

mrbsltz, I assume you are asking about HP rating as you are comparing and shopping for engines? As others have mentioned, the HP ratings are pretty much bogus for the reasons listed. The tach readings on RCU are better, but still subject to a lot of factors such as air density, fuel, etc. so read carefully. There are real world differences between engines of similar size, etc., but unless we are talking extremes, most engines put out comparable power for their design and size, i.e. all 2 cycle .40 bushed motors designed for sport use have about the same power, etc. What you may wish to do is ask for engine combos on a specific plane, or better yet, investigate engines used at your local club if you can. Check out how they perform considering the plane style, prop, fuel used, etc. That should give you a good idea if the engine is suitable for your project/planes. - Cheers
Old 02-01-2021, 10:05 AM
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So when I am looking at a SH G6 gasoline engine they say it is more powerful than an ordinary 46, How can I be confident that this will be what it said it will do.
Old 02-01-2021, 11:59 AM
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daveopam
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The best way for me is to talk to guys who use that product and get opinions. Also ask what size props they are using. This will tell you which one is the most powerful.
You could start y asking for a comparison of both engines in the glow engine forum.

David

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