Talk:Cox model engine
Add topic | This article is rated C-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | |||||||||||||||||
| ||||||||||||||||||
Untitled
[edit]To all you do gooders out they who don't like my "Australian" language wording, please go and find someone else's article's to go and wreck. The aero modellers like this page the way it is. The last Do Gooder, removed a whole section on one type of engine. "standard bees"
Someone has been removing info from this page. Is that called Vandalism? —Preceding unsigned comment added by Warrenlead (talk • contribs) 04:26, 14 June 2009 (UTC)
 | The content of this article has been derived in whole or part from http://www.ebay.com.au/gds/Cox-Model-Aircraft-Engines-/10000000001069165/g.html. Permission has been received from the copyright holder to release this material. Evidence of this has been confirmed and stored by VRT volunteers, under ticket number 2008032910004314. This template is used by approved volunteers dealing with the Wikimedia volunteer response team system (VRTS) after receipt of a clear statement of permission at permissions-en  wikimedia.org. Do not use this template to claim permission. |
"Howto" tip removed from the article
[edit]- Don’t let the castor oil varnish build up inside the cylinder. If the engine won’t hold a needle setting then it probably needs a good clean out with a Scotch-Brite pad.
- Keep the engine clean and free from dust and dirt.
"Fuel intake to the engine is controlled by a simple needle valve and venturi system."
[edit]The TD does have a venturi (and I think the Medallion too though I don't have one). The reed valve bugs, however, have a different sort of carburetor. The Babe Bee, for instance, has a small opening into a larger space, with the wall of the opening extending into the space a bit. The fuel is sucked in through an opening on the side of this dead space. More recent versions use a brass spray bar with the fuel inlet on the down stream side of the bar. A venturi carburetor, such as on a TD, has the fuel jet in the restricted opening where the pressure is low due to a momentum dependent effect. But these have it after the restriction where the velocity is low again. The reduced pressure that sucks the fuel in is not due to bernoulli's principle, but to the restriction of flow by the small opening due to drag. (My brother Larry who tuned racing engines for a living said "I don't see a venturi.")
This may contribute to reliability and versatility because this viscosity based pressure drop is more like the viscosity based restriction of the fuel in the jet. One expects momentum dependent effects to be proportional to the square of the velocity and viscosity dependent effects to be proportional to the velocity. The Reedies have less power dependent mixture than the rotary valves engines. The engineers took advantage of the small scale where viscous effects are large. Apparently the venturi has the lower drag, so it is used on the TD where power is more important than ease of operation. David R. Ingham (talk) 20:56, 22 June 2026 (UTC)