---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Thu 04/03/08: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:20 AM - Re: Used RV buying best practices? (Dave Reel) 2. 07:45 AM - Re: RV7A OVERHEATING (smoothweasel@juno.com) 3. 07:51 AM - Re: Used RV buying best practices? (Dean Pichon) 4. 08:26 AM - Re: RV7A OVERHEATING (Tim Bryan) 5. 08:34 AM - Re: RV7A OVERHEATING (Mike Robertson) 6. 09:30 AM - Re: RV7A OVERHEATING (Kevin Horton) 7. 09:36 AM - Re: RV7A OVERHEATING (J. Mcculley) 8. 09:36 AM - Re: Used RV buying best practices? (Bob) 9. 10:22 AM - Re: RV7A OVERHEATING (Walter Tondu) 10. 10:41 AM - Re: RV7A OVERHEATING (Ed Holyoke) 11. 12:37 PM - Crazy Horse (Bill VonDane) 12. 04:13 PM - Short Notice - Jefferson City, MO Fly-in - KJEF (David Schaefer) ________________________________ Message 1 _____________________________________ Time: 06:20:51 AM PST US From: "Dave Reel" Subject: Re: RV-List: Used RV buying best practices? I think your approach is useful Andrew when you look to buy a used RV. Though some may have been flown little, they may have been built with used engines and components and made primarily to sell. In other cases, such as my RV-8A, the aircraft was made from all new components, flown only 50 hours, and not made to sell but being sold because my health has deteriorated. So you're concerns are guaranteed to be satisfied & you just need to look and take a flight. So, there's a big swing between possibilities depending on how the plane got to the sale market. Good luck. Dave Reel ________________________________ Message 2 _____________________________________ Time: 07:45:31 AM PST US From: "smoothweasel@juno.com" Subject: RE: RV-List: RV7A OVERHEATING Just an update. we are continuing to work on the cooling issues..... the numbers i gave previously are higher now (probably due to higher O.S .A. temp). On a flight yesterday at low alt level flight the numbers are as follows .. TAS 162 (verified by GPS) MP 23 in rpm 2350 (Verified correct) Oil Temp. 232 deg F CHT 395 deg F EGT 1350 (rich of peak) this information was established in constant flight for approx. 45 min. also we connected a magnahelic to the low pressure side of the cowl. (be hind the baffle) at 150 knots we have 4.5" w.c.. we have not tested it o n the entering side yet but 4.5" on the low press raised my eye brows. I then measured the outlet cross sectional area and after taking into acc ount for the ext. stacks it was much smaller than the rv-8 it shares a h anger with and also has a lot more obstacles tripping the airflow and th erefore causing turbulence. I then measured the outlet on my rv-4 and th e -7a even has a smaller outlet than my -4. These are all stock cowls. bottom line we still feel like we have to small of outlet on the cowl. we are still testing.........we shall see. Weasel _____________________________________________________________ Earn up to $300 hour. Click here to get information on starting a medic al career. http://thirdpartyoffers.juno.com/TGL2111/fc/REAK6ZpPCf5s36c9PRQtFyClaNN5 axaGezer7vCfQ07T4GItaLqiML/ ________________________________ Message 3 _____________________________________ Time: 07:51:01 AM PST US From: Dean Pichon Subject: RE: RV-List: Used RV buying best practices? This is an excellent endeavor and would likely be useful to many potential buyers. I have a -4 and can speak better about this model than the others so I will offer a few things. (There are obviously many things to look for , but these are some of the common weak points/issues in -4's and probably other models as well.) Condition of the cowl attachment features (hinges with broken eyelets, fast eners in elongated holes, etc.) Are there wrinkles in the firewall? (Suggesting hard landing(s)) Are the weldments behind the firewall the later (thicker) versions (Photos and dimensions of both versions would be useful) Asymmeterical main gear suggesting one may have been bent Cracks around rivets in elevators and rudder (Was the rudder constructed wi th 0.016 or 0.20 skin?) Does the aircraft have the long or short gear? Longer is newer I'm sure others can add many more. From: andrew@oc384.netTo: rv-list@matronics.comSubject: RV-List: Used RV bu ying best practices?Date: Wed, 2 Apr 2008 10:17:18 -0500 I think a set of Best Practices for used RV pre-buy/purchasing would be hel pful. Has anything like this been compiled before? I=92m thinking about: Indicators of good construction (with photos) Indicators of poor construction (with photos) What to look for in the logs (good and bad) What tests to do? (avionics, engine, etc) Should an Oil Analysis be done? What quirks to be aware of between models=85 I think something like this would be very helpful to any non-A&P shopping f or a used RV. -Andrew _________________________________________________________________ Get in touch in an instant. Get Windows Live Messenger now. http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refr esh_getintouch_042008 ________________________________ Message 4 _____________________________________ Time: 08:26:40 AM PST US From: "Tim Bryan" Subject: RE: RV-List: RV7A OVERHEATING Temperature comparisons are real hard to get but when I added louvers to the bottom of my cowl I gained about 10 degrees cooler CHT temps. I later opened up the exit air and gained about another 5 or 6 degrees. My oil temps run cool at about 165 degrees. My CHT=92s are still high. Very few things I have done made as much difference as the louvers and opening the bottom cowl up a little more. In my case a -6 I just cut the center lower part of the cowl about 1 =BD =93 back as it was actually a little past the metal skin on the fuse. This is just a reference point for you. Tim _____ From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of smoothweasel@juno.com Sent: Thursday, April 03, 2008 8:39 AM Subject: RE: RV-List: RV7A OVERHEATING Just an update. we are continuing to work on the cooling issues..... the numbers i gave previously are higher now (probably due to higher O.S.A. temp). On a flight yesterday at low alt level flight the numbers are as follows. TAS 162 (verified by GPS) MP 23 in rpm 2350 (Verified correct) Oil Temp. 232 deg F CHT 395 deg F EGT 1350 (rich of peak) this information was established in constant flight for approx. 45 min. also we connected a magnahelic to the low pressure side of the cowl. (behind the baffle) at 150 knots we have 4.5" w.c.. we have not tested it on the entering side yet but 4.5" on the low press raised my eye brows. I then measured the outlet cross sectional area and after taking into account for the ext. stacks it was much smaller than the rv-8 it shares a hanger with and also has a lot more obstacles tripping the airflow and therefore causing turbulence. I then measured the outlet on my rv-4 and the -7a even has a smaller outlet than my -4. These are all stock cowls. bottom line we still feel like we have to small of outlet on the cowl. we are still testing.........we shall see. Weasel _____________________________________________________________ Earn up to $300 hour. Click here to get information on starting a medical career. ________________________________ Message 5 _____________________________________ Time: 08:34:19 AM PST US From: Mike Robertson Subject: RE: RV-List: RV7A OVERHEATING With any 'a' model you have tons of obstacles in the outlet area that coaus e all kinds of turbulence. Several people have installed louvers to the le ft and right of the outlet with great results. Your CHT's seem just a tad bit high for the power, rpm, and cruise time you gave. Granted, with a new engine a bit high can be normal but I think they level you gave indicates one of a couple of things. first, check your baffles to make sure they are tight around the engine and upper cowling. Second, make sure the ramp are as of the inlets are smooth and don't have any excess holes. Tthe third th ing is the outlet flow area. Go ahead and get the pressure reading in the top inlet area. Once you compare the top and bottom you will have a much b etter idea. A friend, with an RV-9A, decided to install louvers and had great results. Even though he did not have any temps out of limits, he wanted to see what effect it had. Both the oil temps and the CHTs went down significantly. And with the louvers painted the same color as his cowling they do not look out of place. One quick reminder though. If you do install the louvers, when you cut through the honecomb part of the cowling, make sure to apply s ome eposy glue or resin to the cut areas to stop oil, grease, and water fro m getting into the honeycomb area of the cowling and causing delamination. Mike Robertson Das Fed Repeat offender From: smoothweasel@juno.comDate: Thu, 3 Apr 2008 14:38:51 +0000To: rv-list@ matronics.comSubject: RE: RV-List: RV7A OVERHEATING Just an update. we are continuing to work on the cooling issues..... the numbers i gave previously are higher now (probably due to higher O.S.A. temp). On a flight yesterday at low alt level flight the numbers are as follows. TAS 162 (verified by GPS) MP 23 in rpm 2350 (Verified correct) Oil Temp. 232 deg F CHT 395 deg F EGT 1350 (rich of peak) this information was established in constant flight for approx. 45 min. also we connected a magnahelic to the low pressure side of the cowl. (behin d the baffle) at 150 knots we have 4.5" w.c.. we have not tested it on the entering side yet but 4.5" on the low press raised my eye brows. I then mea sured the outlet cross sectional area and after taking into account for the ext. stacks it was much smaller than the rv-8 it shares a hanger with and also has a lot more obstacles tripping the airflow and therefore causing tu rbulence. I then measured the outlet on my rv-4 and the -7a even has a smal ler outlet than my -4. These are all stock cowls. bottom line we still feel like we have to small of outlet on the cowl. we are still testing.........we shall see. Weasel _____________________________________________________________Earn up to $3 00 hour. Click here to get information on starting a medical career. _________________________________________________________________ More immediate than e-mail? Get instant access with Windows Live Messenger. http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refr esh_instantaccess_042008 ________________________________ Message 6 _____________________________________ Time: 09:30:12 AM PST US From: Kevin Horton Subject: Re: RV-List: RV7A OVERHEATING Speaking of baffling - have a look at the two duct ramp pieces that were fibreglassed to the inlets on the upper cowl. I understand that depending on how you set up your baffles, that it is possible for high pressure air on the top side of the engine to go through the tunnels between those duct ramps and the cowl. The high pressure air may be able to go through those tunnels and end up on the low pressure side of the baffles. It this can happen, it would greatly reduce the amount of air that is available to go through the cylinder fins and the oil cooler. You may need to block off one end of that tunnel with fibreglas. Kevin Horton On 3-Apr-08, at 11:27 , Mike Robertson wrote: > With any 'a' model you have tons of obstacles in the outlet area > that coause all kinds of turbulence. Several people have installed > louvers to the left and right of the outlet with great results. > Your CHT's seem just a tad bit high for the power, rpm, and cruise > time you gave. Granted, with a new engine a bit high can be normal > but I think they level you gave indicates one of a couple of > things. first, check your baffles to make sure they are tight > around the engine and upper cowling. Second, make sure the ramp > areas of the inlets are smooth and don't have any excess holes. > Tthe third thing is the outlet flow area. Go ahead and get the > pressure reading in the top inlet area. Once you compare the top > and bottom you will have a much better idea. > > A friend, with an RV-9A, decided to install louvers and had great > results. Even though he did not have any temps out of limits, he > wanted to see what effect it had. Both the oil temps and the CHTs > went down significantly. And with the louvers painted the same > color as his cowling they do not look out of place. One quick > reminder though. If you do install the louvers, when you cut > through the honecomb part of the cowling, make sure to apply some > eposy glue or resin to the cut areas to stop oil, grease, and water > from getting into the honeycomb area of the cowling and causing > delamination. > > Mike Robertson > Das Fed > Repeat offender > > > From: smoothweasel@juno.com > Date: Thu, 3 Apr 2008 14:38:51 +0000 > To: rv-list@matronics.com > Subject: RE: RV-List: RV7A OVERHEATING > > Just an update. we are continuing to work on the cooling issues..... > the numbers i gave previously are higher now (probably due to higher > O.S.A. temp). > On a flight yesterday at low alt level flight the numbers are as > follows. > TAS 162 (verified by GPS) > MP 23 in > rpm 2350 (Verified correct) > Oil Temp. 232 deg F > CHT 395 deg F > EGT 1350 (rich of peak) > this information was established in constant flight for approx. 45 > min. > also we connected a magnahelic to the low pressure side of the cowl. > (behind the baffle) at 150 knots we have 4.5" w.c.. we have not > tested it on the entering side yet but 4.5" on the low press raised > my eye brows. I then measured the outlet cross sectional area and > after taking into account for the ext. stacks it was much smaller > than the rv-8 it shares a hanger with and also has a lot more > obstacles tripping the airflow and therefore causing turbulence. I > then measured the outlet on my rv-4 and the -7a even has a smaller > outlet than my -4. These are all stock cowls. > bottom line we still feel like we have to small of outlet on the cowl. > we are still testing.........we shall see. > Weasel > > -- Kevin Horton Ottawa, Canada ________________________________ Message 7 _____________________________________ Time: 09:36:49 AM PST US From: "J. Mcculley" Subject: Re: RV-List: RV7A OVERHEATING Can you provide the following additional data that could be helpful: 1. Ambient temperature at the flight altitude. 2. Indicated (calibrated) airspeed. 3. Actual measurements, or best estimate of square inches of clear area of cooling air outlet. 4. Same as 3 above for inlet cooling area. 5. Make/model and face area of oil cooler; Is this a new or used cooler? Also the cross section area of any scat tube feeding the cooler and where that air is sourced; Are all the air leakage cracks at the cooler face thoroughly sealed with the equivalent of red 600 fahrenheit silicon sealant? Does the exit air from the cooler flow out through the same cooling air exit as in item 3 above? 6. What is the sensor pickup location of your oil temperature indication? Are your CHT temperature probes in the cylinder head wells or under the spark plugs? Jim -------------------------------------------------------------------------------------- smoothweasel@juno.com wrote: > Just an update. we are continuing to work on the cooling issues..... > > the numbers i gave previously are higher now (probably due to higher > O.S.A. temp). > > On a flight yesterday at low alt level flight the numbers are as follows. > > TAS 162 (verified by GPS) > > MP 23 in > > rpm 2350 (Verified correct) > > Oil Temp. 232 deg F > > CHT 395 deg F > > EGT 1350 (rich of peak) > > this information was established in constant flight for approx. 45 min. > > also we connected a magnahelic to the low pressure side of the cowl. > (behind the baffle) at 150 knots we have 4.5" w.c.. we have not tested > it on the entering side yet but 4.5" on the low press raised my eye > brows. I then measured the outlet cross sectional area and after taking > into account for the ext. stacks it was much smaller than the rv-8 it > shares a hanger with and also has a lot more obstacles tripping the > airflow and therefore causing turbulence. I then measured the outlet on > my rv-4 and the -7a even has a smaller outlet than my -4. These are all > stock cowls. > > bottom line we still feel like we have to small of outlet on the cowl. > > we are still testing.........we shall see. > > Weasel > > > > > > _____________________________________________________________ > Earn up to $300 hour. Click here to get information on starting a > medical career. > > > * > > > * ________________________________ Message 8 _____________________________________ Time: 09:36:49 AM PST US From: Bob Subject: Re: RV-List: Used RV buying best practices? At 09:17 AM 4/2/08, you wrote: >I think a set of Best Practices for used RV pre-buy/purchasing would >be helpful. Has anything like this been compiled before? I'm thinking about: It would seem to me that the RV world is in a transisition where a lot of RV owners are now or will be non builders. As we see more non builders as RV owners, this issue of how well is an RV built will increasingly become more and more important. In my opinion the best way(s) to learn how to inspect an RV: 1. Build an RV or metal airplane, or 2. Build a non metal airplane, or 3. Read the archives, or 4. Read the Bible that I used to build my RV, "AC 43.13-1B Acceptable Methods, Techniques, and Practices, Aircraft Inspection and Repair." The AC covers all aspects of building, inspection and aircraft repair. It even has pictures, drawings, diagrams, tables etc. There is nothing special about how an RV is built. It uses standard techniques and practices that would be the same for a Mustang II or any of the RV series aircraft. Bob RV6 "Wicked Witch of the West" ________________________________ Message 9 _____________________________________ Time: 10:22:13 AM PST US From: Walter Tondu Subject: Re: RV-List: RV7A OVERHEATING On 04/03 12:18, Kevin Horton wrote: > > Speaking of baffling - have a look at the two duct ramp pieces that > were fibreglassed to the inlets on the upper cowl. I understand that > depending on how you set up your baffles, that it is possible for high > pressure air on the top side of the engine to go through the tunnels > between those duct ramps and the cowl. The high pressure air may be > able to go through those tunnels and end up on the low pressure side > of the baffles. It this can happen, it would greatly reduce the > amount of air that is available to go through the cylinder fins and > the oil cooler. You may need to block off one end of that tunnel with > fibreglas. Follow this thread for more information dissemination and pretty pics about what Kevin is writing about: Also, check out the poll results. http://www.vansairforce.com/community/showthread.php?t=8209 -- Walter Tondu http://www.rv7-a.com - Painting http://www.evorocket.com - Empennage ________________________________ Message 10 ____________________________________ Time: 10:41:44 AM PST US From: Ed Holyoke Subject: Re: RV-List: RV7A OVERHEATING Weasel, Just as a data point, on our 6A with O-320, we used to see oil temps in the 200 to 220 degree range on not very hot days until we moved the oil cooler from the firewall to behind the baffle at #4 cyl. Do the math of cross sectional area in the scat tube to surface area of the oil cooler then think about length of tube, bends etc. In our case, with 3" scat, it was 1.5" squared x pi, or about 7 sq" with 18" of scat and 1 bend vs. 4 x 5 or about 20 sq" directly in the airflow. Now we see 180 to 190 degrees on warm days. This is the Niagara cooler. I'm not sure which one Van's supplies now, but I don't think that it is the Stewart Warner which is the one you really want. Others have made good suggestions about cowl airflow. I think that you probably need to address the airflow through the cooler as a separate issue. One approach might be to combine 2 or more scats into a plenum above the oil cooler. What out that you don't create a bunch of turbulence, though. Stuff in the exit airflow path from the cooler can have a negative impact on cooling performance, too. Pax, Ed Holyoke smoothweasel@juno.com wrote: > > Hello all, It's been a long time since i have found time to read "the > list". I have been helping a friend finish a rv-7a and test fly it. > It has a new superior 360 parallel valve engine, Hartzell blended > airfoil prop, the oil cooler is the one that comes with the finishing > kit and is mounted on the firewall with a 3.5 in scat duct going to it > (with no sharp bends in the duct). the cowl air exit is the standard > size. ie. no extra openings. > > His problem is over heating oil. With 52 deg. F. Outside air crusing > at 24 in map. and 2350rpm on the prop the oil will run about > 220-225deg F. The CHT runs about 360-370 deg. F. The engine now has > 30hr or more on it. > > Will the Oil temp drop any more with "break in"? Should it have more > exit air leaving the cowl....some have suggested installing "luvers" > on the botom of the cowl to help with that...? > > Also the airplane cruises at the above power setting at 8000ft at > 164kn TAS he thinks this is a little slow...... Is this what most of > you are seeing with the same engine/prop combo??? > > btw i tried to search the archives on this but didnt find the specific > info..........probably dont know how to look it up right... > > > > Thanks for any thoughts > > Weasel RV-4 400hr > > > _____________________________________________________________ > Click here to become a professional counselor in less time than you > think. > > * > > > * ________________________________ Message 11 ____________________________________ Time: 12:37:24 PM PST US From: Bill VonDane Subject: RV-List: Crazy Horse You say you want to fly Crazy Horse? http://www.airshowbuzz.com/videos/view.php?v=baccdea1 do not archive ________________________________ Message 12 ____________________________________ Time: 04:13:36 PM PST US From: "David Schaefer" Subject: RV-List: Short Notice - Jefferson City, MO Fly-in - KJEF I received this email earlier in the day: *As I promised late last year, here is you notice of a last minute fly in. Weather is scheduled to be 'SUNNY' !!* *Once again, the owner of 'NICKS' restaurant has agreed to open his doors on Saturday just for this fly in and he will be serving 11 A.M. -- 2 P.M. on April 5th.* *A partial menu follows:* *Country Fried Ham Plates or Sandwiches* *Country Fried Chicken Plates or Sandwiches* *Pork Tenderloin Plates or Sandwiches* *Fish Plates or Sandwiches* *There is no 'formal program'.....just a short notice plain ol' fly in and maybe some hangar/war stories.* *Additionally, L.C. Flight Shop located in the terminal building next to the Nick's Restaurant will be open between 10 A. M. and 3 P.M. for your convenience. Also Jefferson City Flying Service will have a couple of additional linemen on duty to assist with the parking. * *The Jefferson City Tower Frequency is: 125.6 and we now have a new parallel taxi way for runway 12/30.* *I will appreciate it very much if you would be so kind as to respond to the undersigned with the type aircraft and number in your party along with an approximate time of arrival. Email or telephonic response either will work! * *Looking forward to meeting you,* *Bob Morgan* *Cell: 573-680-5211 Bob Morgan [N1142G@mchsi.com] * ** Since the weather is supposed to be nice. I wanted to pass it on to the rest of the RV Community. -- David W. Schaefer RV-6A N142DS formerly "Geek One' reborn "Nerdgasm" TMX-IO360 Dual-LightSpeed Plasma IIIs, Hartzell Blended Airfoil, GRT EFIS www.n142ds.com ------------------------------------------------------------------------------------- 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.