---------------------------------------------------------- Glasair-List Digest Archive --- Total Messages Posted Thu 06/08/17: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:02 PM - 25 mph with wing root fairings (mppalmer@aol.com) 2. 01:19 PM - Carb mod (mppalmer@aol.com) ________________________________ Message 1 _____________________________________ Time: 01:02:41 PM PST US From: mppalmer@aol.com Subject: Glasair-List: 25 mph with wing root fairings This guy claims a 25 mph increase in speed with custom wing root fairings. barnstormers.com/classified_1253825_GLASAIR+SH-2R.html I'm in the process of making some traditional (large curve) fairings. postimg.org/image/pa6ze7gk3/ ________________________________ Message 2 _____________________________________ Time: 01:19:47 PM PST US From: mppalmer@aol.com Subject: Glasair-List: Carb mod I had a chance meeting with a Formula 1 racer. He races in a class where you can only make simple mods to a production engine. One of the mods he suggested that I try was to 1) smooth the vanes on the venturi in the carb and 2) twist the vanes in the venturi to "swirl" the air. I couldn't twist our vanes, because we have a one piece venturi. (But you might be able to do it if you kept the 2 piece (Despite the AD.)) But I could smooth out the blunt edge of the vanes. And I smoothed them out asymmetrically, in the hope that I could impart a swirl to the air flow. So I did. postimg.org/image/4y84e4csd/ It seemed to me that rounding the leading edge of the vanes on the venturi was a no brainer, in the sense that air in the venturi is probably running at about 100 mph, and those blunt edges had to be making drag, turbulence and a large wake. I couldn't tell a night/day performance difference after doing the mod. But then, I don't turn the engine at 4000 rpm, like my new-found racer buddy. Maybe I picked up a half inch of MP. Can't really say. But I notice that the EGT distributions are more even now and I can lean further than I used to. I can now get down to 6.5 GPH (WOT) at altitude. Whereas before, 7.2. (This is with one mag replaced by an Electron ignition, with advanced timing.) Speed is the same at LOP, which is why I think I might have picked up a half inch MP. (The increase in MP offset the leaner mixture.) Anyway, it's an easy enough mod to make when you have the carb apart. I can't see a downside. Only an upside. Mike Palmer <>< ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message glasair-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Glasair-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/glasair-list Browse Digests http://www.matronics.com/digest/glasair-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.