---------------------------------------------------------- JabiruEngine-List Digest Archive --- Total Messages Posted Sat 05/02/09: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:55 AM - Re: Gull Wing Mods (TELEDYNMCS@aol.com) 2. 02:10 PM - Re: Re: Gull Wing Mods (Dale Hetrick) ________________________________ Message 1 _____________________________________ Time: 05:55:01 AM PST US From: TELEDYNMCS@aol.com Subject: JabiruEngine-List: Re: Gull Wing Mods In a message dated 5/2/2009 3:08:12 A.M. Eastern Daylight Time, jabiruengine-list@matronics.com writes: Have you done this mod???? Greetings, I have a 3300 installed in a Europa. About two years ago I modified the "gull wings" to include a hole in them about one sq. in. or so in total area on each wing. The shape of the hole resembles a pentagram with the pointy side towards the crankcase. This allows air to spill down the inside of the heads and between the cylinder barrels. While the gull wing is not completely removed, this modification did help with lowering head temps in climb. I recall I tested with the gull wings removed completely and it did not help my set up. Last fall I added a "step" or reverse scoop to my lower cowl just before the exit hole. This step, or reverse scoop, serves to create an area of low pressure at the point where the cooling flow exits the lower cowl. The effect is similar to the "lips" often seen on lower cowls, but is more aerodynamic. The step was molded onto the lower cowl by carefully shaping foam, then glassing over it and painting. It extends about 4" below the lower cowl and belly of the aircraft and is approximately 10" wide, equal to the width of the exit hole. This helped significantly. Essentially, what I did was copy what Mooney, Cirrus, Columbia and other "modern" aircraft are doing in regard to their lower cowls to enhance exit cooling flow. It also hides the exhaust stacks and helps to hide the Europa's lower stainless firewall and nose gear leg gusset from the relative wind in climb and cruise attitudes. Both the lower fire wall and nose gear leg gusset were flat to the airflow in climb and somewhat exposed in cruise. Manometer testing showed that these two components were causing an area of high pressure at the exit hole prior to the installation of the step. The change in the gull wings and the addition of the step on the lower cowl reduced the ambient pressure inside the internal head cooling ducts, increasing flow, and lowering head temps by an average of 25F. Pictures available upon request. Regards, John Lawton Whitwell, TN (TN89) Europa N245E - Flying **************Access 350+ FREE radio stations anytime from anywhere on the web. Get the Radio Toolbar! (http://toolbar.aol.com/aolradio/download.html?ncid=emlcntusdown00000003) ________________________________ Message 2 _____________________________________ Time: 02:10:07 PM PST US From: "Dale Hetrick" Subject: Re: JabiruEngine-List: Re: Gull Wing Mods Hi John, Your idea(s) seem very sound to me, therefore I would appreciate the proffered photos. Many thanks, Dale Tri-Gear/3300 ----- Original Message ----- From: TELEDYNMCS@aol.com To: jabiruengine-list@matronics.com Sent: Saturday, May 02, 2009 5:50 AM Subject: JabiruEngine-List: Re: Gull Wing Mods In a message dated 5/2/2009 3:08:12 A.M. Eastern Daylight Time, jabiruengine-list@matronics.com writes: Have you done this mod???? Greetings, I have a 3300 installed in a Europa. About two years ago I modified the "gull wings" to include a hole in them about one sq. in. or so in total area on each wing. The shape of the hole resembles a pentagram with the pointy side towards the crankcase. This allows air to spill down the inside of the heads and between the cylinder barrels. While the gull wing is not completely removed, this modification did help with lowering head temps in climb. I recall I tested with the gull wings removed completely and it did not help my set up. Last fall I added a "step" or reverse scoop to my lower cowl just before the exit hole. This step, or reverse scoop, serves to create an area of low pressure at the point where the cooling flow exits the lower cowl. The effect is similar to the "lips" often seen on lower cowls, but is more aerodynamic. The step was molded onto the lower cowl by carefully shaping foam, then glassing over it and painting. It extends about 4" below the lower cowl and belly of the aircraft and is approximately 10" wide, equal to the width of the exit hole. This helped significantly. Essentially, what I did was copy what Mooney, Cirrus, Columbia and other "modern" aircraft are doing in regard to their lower cowls to enhance exit cooling flow. It also hides the exhaust stacks and helps to hide the Europa's lower stainless firewall and nose gear leg gusset from the relative wind in climb and cruise attitudes. Both the lower fire wall and nose gear leg gusset were flat to the airflow in climb and somewhat exposed in cruise. Manometer testing showed that these two components were causing an area of high pressure at the exit hole prior to the installation of the step. The change in the gull wings and the addition of the step on the lower cowl reduced the ambient pressure inside the internal head cooling ducts, increasing flow, and lowering head temps by an average of 25F. Pictures available upon request. Regards, John Lawton Whitwell, TN (TN89) Europa N245E - Flying ------------------------------------------------------------------------- ----- Access 350+ FREE radio stations anytime from anywhere on the web. 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