---------------------------------------------------------- Lightning-List Digest Archive --- Total Messages Posted Thu 02/21/08: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:31 AM - Re: Cylinder cooling (Daniel DW) 2. 01:46 PM - Re: Cylinder cooling (N1BZRich@aol.com) 3. 01:52 PM - Just for Grins- follow up (N1BZRich@aol.com) 4. 02:09 PM - Lightning bottom cowl air dam photos (N1BZRich@aol.com) 5. 06:18 PM - Re: Just for Grins- follow up (Jim and Mary Young) 6. 06:52 PM - Re: Lightning bottom cowl air dam photos (JOSEPH MATHIAS LINDA MATHIAS) 7. 10:59 PM - FW: Lightning bottom cowl air dam photos (James, Clive R) 8. 10:59 PM - FW: Cylinder cooling (James, Clive R) 9. 11:52 PM - Re: Lightning bottom cowl air dam photos (Brian Whittingham) ________________________________ Message 1 _____________________________________ Time: 05:31:02 AM PST US From: Daniel DW Subject: RE: Lightning-List: Cylinder cooling Buz, a picture of the lip or "air dam" on the Lightning cowl would be nice :-)) Danny > Date: Thu, 21 Feb 2008 14:09:12 +1100> From: punga-iwi@netspace.net.au> T o: lightning-list@matronics.com> Subject: Lightning-List: Cylinder cooling> In a message dated 2/20/2008 8:13:07 P.M. Eastern Standard Time, > allanma xe@yahoo.com writes:> > I ment cht > > OK, Allen, then here are some though ts on CHTs:> Remember the key to good cylinder cooling on the jabiru powere d > Lightning or Esqual is high pressure on top of the cylinders and low > pressure under them. That makes sure the air flows from top to bottom > thr ough the cooling fins and thus cools the cylinders. So make sure all > air coming in through the two nose bowl intakes can only go to the area > above the cylinders. Close up the area between the nose bowl and the > Jabiru su pplied fiberglass intake ducts to insure all intake air only > goes into th e fiberglass ducts. On the bottom cowl, to insure a lower > pressure, the L ightning cowl has a lip or "air dam" that creates a lower > pressure area i nside the lower cowl. This also insures the cooling air > moves from top to bottom. I don't remember if the Esqual bottom cowl > has that or not since my airplane is total Lightning from firewall > forward. So if the Esqual d oes not have a lip on the bottom cowl, make > one using fiberglass or even aluminum. Once both of these things are > done, then you can fine tune the CHTs for individual cylinders by adding > small "deflectors" inside the fib erglass ducts over the cylinder than > needs more cooling. Start with these "eyebrow shaped" deflectors (so > they match up to the concave shape of th e inside of the ducts) being > about three inches long by 3/8 inch deep. Th ey trim them down if they > end up blocking too much air to the cylinder be hind them. On my set up > I have two deflectors on each side over the middl e and aft cylinders. > This "experimenting" is what home built aircraft is all about - kind of > trial and error. > I think the hottest cylinder that I ever see on N31BZ is around 320 > during a climb out on a really hot 100 degree day here in Virginia. By > the time I am climbing through about 3000 feet the temp then starts back > down from the high of 320 or so. Cruise t emps are all well below 300. > So we know the above will work.> As I mentio ned in the previous e-mail. You really should attend the > Jabiru engine se minar. Certainly time and money well spent. You will > not only talk about this type of thing, but will get to actually see how > the small deflectors are glued inside the intake ducts. > Blue Skies,> Buz> > > > > ----------- -------------------------------------------------------------> Delicious id eas to please the pickiest eaters. Watch the video on AOL > Living. > > > _________________________________________________________________ Een gelukkig nieuwjaar vanwege Windows Live...Download het nu gratis! http://get.live.com ________________________________ Message 2 _____________________________________ Time: 01:46:52 PM PST US From: N1BZRich@aol.com Subject: Re: Lightning-List: Cylinder cooling In a message dated 2/21/2008 8:32:45 A.M. Eastern Standard Time, ddw55@hotmail.com writes: a picture of the lip or "air dam" on the Lightning cowl would be nice Danny, I have looked through my photo files and can not find one that shows the Lightning's bottom cowl. May have to take one the next time I remember to take my camera to the airport. Sorry, Buz **************Ideas to please picky eaters. Watch video on AOL Living. (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy/ 2050827?NCID=aolcmp00300000002598) ________________________________ Message 3 _____________________________________ Time: 01:52:06 PM PST US From: N1BZRich@aol.com Subject: Lightning-List: Just for Grins- follow up As a follow up to yesterday's "just for grins" message, it has been confirmed that the automotive Garmen Street Pilot GPS really does show speeds in excess of 200 MPH. And no, I did not do this test in a car. Blue Skies, Buz **************Ideas to please picky eaters. Watch video on AOL Living. (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy/ 2050827?NCID=aolcmp00300000002598) ________________________________ Message 4 _____________________________________ Time: 02:09:30 PM PST US From: N1BZRich@aol.com Subject: Lightning-List: Lightning bottom cowl air dam photos Danny, Right after I sent the previous message I remembered where you could see the lip on the Lightning's bottom cowl. Go to the Lightning news web page _http://www.arionaircraft.com/News.html_ (http://www.arionaircraft.com/News.html) , and scroll down to near the bottom and look at the photos for 1/5/2006, Lightning Cowl Finalized, and also 2/15/2005, Wheel and gear fairings set for trial. Both of these set of photos show the lip or air dam. The idea is the same as on a car. The air dam forces air down and thus creates a lower pressure area under the bottom cowl. Hope this helps. Buz **************Ideas to please picky eaters. Watch video on AOL Living. (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy/ 2050827?NCID=aolcmp00300000002598) ________________________________ Message 5 _____________________________________ Time: 06:18:47 PM PST US From: "Jim and Mary Young" Subject: RE: Lightning-List: Just for Grins- follow up Unfortunately, I fly commercial a lot. I've been able to use my Delorme Earthmate GPS at altitude. It does register the speed of the airliner and shows the progress on the map. The last time I flew, the steward asked me to put it away as they are not allowed. I didn't say anything and politely put it away assuming it would not do any good to argue that it is a receive only device and would not interfere with anything. Jim Young _____ From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of N1BZRich@aol.com Sent: Thursday, February 21, 2008 4:50 PM Subject: Lightning-List: Just for Grins- follow up As a follow up to yesterday's "just for grins" message, it has been confirmed that the automotive Garmen Street Pilot GPS really does show speeds in excess of 200 MPH. And no, I did not do this test in a car. Blue Skies, Buz _____ Delicious ideas to please the pickiest eaters. Watch the video on AOL Living. ________________________________ Message 6 _____________________________________ Time: 06:52:34 PM PST US From: "JOSEPH MATHIAS LINDA MATHIAS" Subject: Re: Lightning-List: Lightning bottom cowl air dam photos Danny, These pictures might give you the idea; I cut the lip off to clear the exhaust because it was touching and burning the cowl. However, that raised temps a lot so I had to put a lip back on but moved it about 3/4 inch farther forward. I think you can see the shape of it though and get the idea. Linda ----- Original Message ----- From: N1BZRich@aol.com To: lightning-list@matronics.com Sent: Thursday, February 21, 2008 5:06 PM Subject: Lightning-List: Lightning bottom cowl air dam photos Danny, Right after I sent the previous message I remembered where you could see the lip on the Lightning's bottom cowl. Go to the Lightning news web page http://www.arionaircraft.com/News.html, and scroll down to near the bottom and look at the photos for 1/5/2006, Lightning Cowl Finalized, and also 2/15/2005, Wheel and gear fairings set for trial. Both of these set of photos show the lip or air dam. The idea is the same as on a car. The air dam forces air down and thus creates a lower pressure area under the bottom cowl. Hope this helps. Buz ------------------------------------------------------------------------- --- Delicious ideas to please the pickiest eaters. Watch the video on AOL Living. ------------------------------------------------------------------------- ------- ________________________________ Message 7 _____________________________________ Time: 10:59:28 PM PST US Subject: FW: Lightning-List: Lightning bottom cowl air dam photos From: "James, Clive R" Apologies I should have carried on reading the next few posts. Though my comments still apply. Looking at the pictures of the Lightning ducts and my Esquals the size difference is massive. Worth some 'liquid engineering' if there's space. Regards, Clive -----Original Message----- From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of N1BZRich@aol.com Sent: 21 February 2008 22:07 Subject: Lightning-List: Lightning bottom cowl air dam photos Danny, Right after I sent the previous message I remembered where you could see the lip on the Lightning's bottom cowl. Go to the Lightning news web page http://www.arionaircraft.com/News.html, and scroll down to near the bottom and look at the photos for 1/5/2006, Lightning Cowl Finalized, and also 2/15/2005, Wheel and gear fairings set for trial. Both of these set of photos show the lip or air dam. The idea is the same as on a car. The air dam forces air down and thus creates a lower pressure area under the bottom cowl. Hope this helps. Buz ________________________________ Delicious ideas to please the pickiest eaters. Watch the video on AOL Living. ________________________________ Message 8 _____________________________________ Time: 10:59:49 PM PST US Subject: FW: Lightning-List: Cylinder cooling From: "James, Clive R" Here's one of Buz's Esqual's LS cowling, a bit grainy but shows the cowling opening. It looks smaller than the Esqual which also has a lip. How the actual airflow is affected with each, of course, would need testing but anecdotal results just show the overall cooling package of the Esqual is poor. This because the cowling was designed for the Rotax. Park my Esqual in a breeze after it's been running and there is plenty of heat coming out the bottom of the cowl. I think cooling issues with the Esqual is all around the front opening and the ducts. Just what Pete and the guys changed with the Lightning cowlings. I think there will be enough air flow out of the Esqual cowling opening it's just very tight inside the ducts so that air will be 'choked' so the flow restricted. One recent suggestion on the engine forum to improve 3300 cooling is to modify the ducts like the type where the spark plugs and leads are inside the ducts, this is as later 3300 engine ducts are. Whether we can do this within the tight confines of the Esqual top cowling I don't know. Will take a look next time I'm home. Early 3300 engine in Jabiru's own J series planes also have cooling issues and the cowlings were subsequently changed more like the Lightning, though not as good it has to be said. Regards, Clive -----Original Message----- From: owner-lightning-list-server@matronics.com [mailto:owner-lightning-list-server@matronics.com] On Behalf Of N1BZRich@aol.com Sent: 21 February 2008 21:44 Subject: Re: Lightning-List: Cylinder cooling In a message dated 2/21/2008 8:32:45 A.M. Eastern Standard Time, ddw55@hotmail.com writes: a picture of the lip or "air dam" on the Lightning cowl would be nice Danny, I have looked through my photo files and can not find one that shows the Lightning's bottom cowl. May have to take one the next time I remember to take my camera to the airport. Sorry, Buz ________________________________ Delicious ideas to please the pickiest eaters. Watch the video on AOL Living. ________________________________ Message 9 _____________________________________ Time: 11:52:48 PM PST US From: Brian Whittingham Subject: RE: Lightning-List: Lightning bottom cowl air dam photos Clive, Somewhere around here I have a book that tells about cooling design and eliminating drag. There's a particular ratio that you want to look for bet ween entry area and exit area. The "lip" on the Lightning cowling helps to drop the pressure following it and creates an air pump if you will. It's giving ram effect cooling. Now if you have too little of an opening for th e exit the air will tend to build up and spill back out the cowling in fron t and cause greater cooling drag and less efficiency. If you have too smal l of an opening in the front for the size of the rear, then you have air pu lling through the openings like it should, but not enough quantity to poten tially be inadequate. What I would like to see is somebody take it upon th eir selves, maybe with a background in engineering, and modify their cowlin g such as this: http://www.airliners.net/photo/Untitled/Lancair-Legacy-2000/0454138/L/ Also see a better view of the bottom of the cowl here: http://www.airliners.net/photo/Untitled/Lancair-Legacy-2000/0647171/L/ The first pic is most applicable. In this case, the air exits via two outl ets which shroud the exaust. These protrude into the airstream a little an d cause a partial pressure drop. The big drop in pressure comes from the e ntry/exit sizes though. The air from the cowling exits around the exhaust stacks. The nosegear strut is faired in and glassed to the bottom of the p lane. Sure, some of you are going to say, well what about temperature arou nd those exhausts. Temperature will make that pressure drop less than it c ould if it were cool air and a dedicated duct. Well, the effects of temp o n pressure decrease as the mass flow increases, to the point to where it ha s virtually no impact if you design the cowl right. Having said all of that. The Lightning cowl is very efficient at cooling. It was designed with the entry/exit area in mind. Pete has commented befo re that if they were to focus on any kind of drag reduction in the future, the cowl would be one of those. It's great at cooling, pretty good in drag , but could be a little better. If some of you engineer types had the know how to modify and do a little testing and present the findings to Arion, i f they were favorable to the point of being worthwhile, then you might get a little chance to help make a great design even better! >From the flight testing that I did, it is possible to get a little higher s peeds out of the Lightning with simple drag reduction, but you're close to Vne as it is. My focus would be on improving drag and instead of cruising faster, being able to pull the throttle back a little more at high altitude cruise. I think that Earl emailed me that he got 0.2-0.3 gph better fuel burn with his gap seals. It doesn't sound like a lot but if you can get 0. 3 here and 0.2 there, then it would be possible to get 4 something gph in c ruise in a Lightning and save 10% on fuel costs per year. If you fly 100 h ours a year, if gas was $3.50/gallon, it amounts to an additional $175 on f uel. The bigger savings may come in the long run though as you will likely be running cooler and therefore improving the overall life and maintenance cost of the engine. Just a few thoughts. Anybody else have any ideas on the matter. Brian W. ___________________________________________________________ > Subject: FW: Lightning-List: Lightning bottom cowl air dam photos> Date: Fri, 22 Feb 2008 06:55:55 +0000> From: clive.james@uk.bp.com> To: lightning -list@matronics.com> > Apologies I should have carried on reading the next few posts. Though my> comments still apply. > > Looking at the pictures of the Lightning ducts and my Esquals the size> difference is massive.> > Wort h some 'liquid engineering' if there's space.> > Regards, Clive> > -----Ori ginal Message-----> From: owner-lightning-list-server@matronics.com> [mailt o:owner-lightning-list-server@matronics.com] On Behalf Of> N1BZRich@aol.com > Sent: 21 February 2008 22:07> To: lightning-list@matronics.com> Subject: Lightning-List: Lightning bottom cowl air dam photos> > Danny,> Right after I sent the previous message I remembered where you could> see the lip on t he Lightning's bottom cowl. Go to the Lightning news> web page http://www.a rionaircraft.com/News.html, and scroll down to near> the bottom and look at the photos for 1/5/2006, Lightning Cowl> Finalized, and also 2/15/2005, Wh eel and gear fairings set for trial.> Both of these set of photos show the lip or air dam. The idea is the> same as on a car. The air dam forces air d own and thus creates a lower> pressure area under the bottom cowl. Hope thi s helps.> Buz> > > > ________________________________> > Delicious ideas to please the pickiest eaters. Watch the video on AOL> Living.> s-duffy/205082 7?NCID=aolcmp00300000002598> _________________________________________________________________ Connect and share in new ways with Windows Live. http://www.windowslive.com/share.html?ocid=TXT_TAGHM_Wave2_sharelife_0120 08 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message lightning-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Lightning-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/lightning-list Browse Digests http://www.matronics.com/digest/lightning-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.