---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Sun 10/25/09: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:14 AM - Re: Mag & Alternator Cooling Blast Tubes... (Charles Kuss) 2. 09:52 AM - Re: Mag & Alternator Cooling Blast Tubes... (Linn Walters) 3. 10:13 AM - Re: Mag & Alternator Cooling Blast Tubes... (Charles Kuss) ________________________________ Message 1 _____________________________________ Time: 04:14:15 AM PST US From: Charles Kuss Subject: RE: RV-List: Mag & Alternator Cooling Blast Tubes... Matt, Many Lycomings have shrouds as well as blast tubes for the magnetos. I purchased a pair of used magneto shrouds from a local certified engine shop. Heat and vibration are the enemies of anything electrical, like magnetos and alternators. To properly protect an ND alternator, you need to understand how the cooling fans work. Your PlanePower ND alternator has two internal fans [mounted on the rotor shaft, internal to the cases]. These fans draw air in from both the front and the rear of the alternator case. This air is expelled through the slots located around the middle circumference of the alternator. Lycoming engines spin opposite to what most car engines rotate. Honda engines rotate clockwise, as do our Lycomings. This means that an ND alternator off of something other than a Honda, will have the fans running backwards. Planepower's brag relates to the fact that it has the correct fan rotation for optimum cooling [clockwise]. I would recommend that you either aim your blast tube towards the rear of your alternator. An even better option would be to fabricate a shroud for the rear of the alternator and install the blast tube to the shroud. See attached photos of David Brand's very nice alternator shroud. For folks using an ND alternator with internal fans which is NOT from a Honda, aim the blast tube at the slots around the circumference of the middle of the unit. Since the fans will be running in reverse, the air is being drawn in where it should be expelled. I hope this helps. Charlie Kuss PS I'll try to take a photo of my magneto shrouds later today. I'm looking over this cooling blast tube kit from Van's (DUCT CBT-5/8) and deciding what needs cooling and what doesn't. I'm guessing the Slick Mags do. The directions are pretty clear on how to mount the tube in the baffle, but don't mention at all where to shoot the air in around the mag. Is just in the general vacineity good enough, or is there a little hole in the mag that wants fresh air? > >I've also got the PlanePower 60amp alternator that Van's sells. The instruction booklet that comes with it brags about how, because of its design, it runs much cooler that traditional automobile conversions do. Okay, great. But does that mean that it still needs a blast tube off the front baffle for cooling? If so, same question on the mags. Where's a good place to stick the cool air on the alternator? > >Thanks in advance for the feedback, > >Matt Dralle ________________________________ Message 2 _____________________________________ Time: 09:52:53 AM PST US From: Linn Walters Subject: Re: RV-List: Mag & Alternator Cooling Blast Tubes... Charlie, do you know what aircraft the shrouds came from??? I've never seen them! 'Course I'm no expert either! ! My little Grumman (AA-1B O-235) does have a cooling shroud ..... around the oil screen ..... which has the temp probe ..... to get past the FAA testing! Linn Charles Kuss wrote: > Matt, > Many Lycomings have shrouds as well as blast tubes for the magnetos. ________________________________ Message 3 _____________________________________ Time: 10:13:48 AM PST US From: Charles Kuss Subject: Re: RV-List: Mag & Alternator Cooling Blast Tubes... Linn, I'm not sure. Might have been off of a Piper Cherokee??? Charlie --- On Sun, 10/25/09, Linn Walters wrote: > From: Linn Walters > Subject: Re: RV-List: Mag & Alternator Cooling Blast Tubes... > To: rv-list@matronics.com > Date: Sunday, October 25, 2009, 12:51 PM > Linn Walters > > Charlie, do you know what aircraft the shrouds came > from??? I've never seen them! 'Course I'm no > expert either! ! > > My little Grumman (AA-1B O-235) does have a cooling shroud > ..... around the oil screen ..... which has the temp > probe ..... to get past the FAA testing! > Linn > > Charles Kuss wrote: > > Matt, > > Many Lycomings have shrouds as well as blast > tubes for the magnetos. > > Forum - > FAQ, > - MATRONICS WEB FORUMS - > List Contribution Web Site - > -Matt > Dralle, List Admin. > > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv-list Browse Digests http://www.matronics.com/digest/rv-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.