RCU Forums - View Single Post - diference in performance on engines question please.

05-15-2011 | 01:36 AM

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DarZeelon

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From: Rosh-HaAyin, ISRAEL

RE: diference in performance on engines question please.

Quote:

ORIGINAL: Kweasel

The published HP figures are not far off with an open exhaust. In actual use think of a 90 as around 20% more power than a 60.
Supertigre 75-90s are very good ''60'' sized engines with carbs that many people struggle with.

Ken,

The published HP claims made by most engine manufacturers, are usually overly optimistic; even if tested in open-exhaust configuration.

If you look, for example, at [link=http://supertigre.com/engines/supg0235-man.html]this review of the ST S.90[/link] by Mike Billinton, it states "Max. b.hp 2.35 @ 14,418rpm (open exhaust/5% nitro)".

The [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFV79&P=ML]product page[/link] on the Tower Hobbies web site, states "Output: 2.5 bhp at 14,800 rpm".

And in this day and age; who would be crazy enough to run his glow engine with an open exhaust?! It needs a muffler to idle...

There must be a standard established, for maximum output claims made by engine manufacturers; which ANY modeler will be able to duplicate, with the engine he/she received, as it comes equipped from the factory.

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