---------------------------------------------------------- RV10-List Digest Archive --- Total Messages Posted Sun 11/11/12: 26 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:09 AM - Re: Problem with Fuel flow transducer in the tunnel (Bob Leffler) 2. 04:46 AM - Re: Problem with Fuel flow transducer in the tunnel (Tim Olson) 3. 05:53 AM - Re: Problem with Fuel flow transducer in the tunnel (jkreidler) 4. 06:07 AM - Re: Problem with Fuel flow transducer in the tunnel (bill.peyton) 5. 06:36 AM - Re: Re: Problem with Fuel flow transducer in the tunnel (Pascal) 6. 06:38 AM - Re: Re: Problem with Fuel flow transducer in the tunnel (bob-tcw) 7. 06:58 AM - Re: Problem with Fuel flow transducer in the tunnel (bill.peyton) 8. 07:17 AM - Re: Re: Problem with Fuel flow transducer in the tunnel (Kelly McMullen) 9. 07:27 AM - Re: Re: Problem with Fuel flow transducer in the tunnel (Kelly McMullen) 10. 08:25 AM - Re: Opinion please (Ed Godfrey) 11. 08:37 AM - Opinions please (Ed Godfrey) 12. 08:51 AM - Re: Opinions please (davidsoutpost@comcast.net) 13. 09:08 AM - rudder trim RV-10 (J. R. (Dick) Dial) 14. 11:37 AM - Re: Problem with Fuel flow transducer in the tunnel (Fred Williams) 15. 12:07 PM - Re: Elevator skin (Terry Moushon) 16. 01:10 PM - Re: rudder trim RV-10 (Bob Leffler) 17. 01:36 PM - Re: Problem with Fuel flow transducer in the tunnel (Jesse Saint) 18. 01:52 PM - Re: Re: Problem with Fuel flow transducer in the tunnel (bob-tcw) 19. 01:55 PM - Re: Problem with Fuel flow transducer in the tunnel (bob-tcw) 20. 03:35 PM - Re: Problem with Fuel flow transducer in the tunnel (billz) 21. 05:14 PM - Rigging thoughts (Carl Froehlich) 22. 05:22 PM - Re: Elevator Rib Tip Assembly (Ed Kranz) 23. 05:24 PM - Re: Elevator Rib Tip Assembly (Ed Kranz) 24. 06:12 PM - Re: Red Cube FWF install (Rick Lark) 25. 08:04 PM - Re: Red Cube FWF install (Seano) 26. 08:30 PM - Re: Problem with Fuel flow transducer in the tunnel (rv10flyer) ________________________________ Message 1 _____________________________________ Time: 12:09:00 AM PST US Subject: Re: RV10-List: Problem with Fuel flow transducer in the tunnel From: Bob Leffler Bob, Thanks for documenting your findings! Thankfully, I had already placed my r ed cube fwf. I'm disappointed in Van's traditional "not invented here" response. Your e mpirical data, along with the many RV-10s with the cubes fwf, you would thin k Van's would listen and consider that there may be another way of doing thi ngs that may be better. Bob Sent from my iPad On Nov 10, 2012, at 8:32 PM, "bob-tcw" wrote: > Fellow builders, > > Some of you may be aware that I=99ve seen some deviations in fuel pr essure and flow in cruise flight in my RV-10: I=99ve got to root cau se. > > After the past 10 months of investigation and discussions and general head scratching I finally have come to a conclusion. > > Executive summary: Don=99t mount the fuel flow sender in the tunnel per the plans! It has too much pressure drop and gets too warm in this loc ation, this can lead to vapor lock. The onset seen as deviations in fuel p ressure and fuel flow. > > > The full report can be downloaded at: > > http://tcwtech.com/Fuel%20flow%20write-up.pdf > > > Bob Newman > N541RV > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 2 _____________________________________ Time: 04:46:25 AM PST US Subject: Re: RV10-List: Problem with Fuel flow transducer in the tunnel From: Tim Olson It may be that the red cube sensor is more picky than others. I've never had a complaint about it, but mine is a flo scan. It seems the complaints all s eem to come from those with the cube. So may e there is a difference. I *th ink* the floor bracket holes were a perfect match for the flo scan, so that m ay be what they used and designed around. Tim On Nov 11, 2012, at 2:08 AM, Bob Leffler wrote: > Bob, > > Thanks for documenting your findings! Thankfully, I had already placed m y red cube fwf. > > I'm disappointed in Van's traditional "not invented here" response. Your empirical data, along with the many RV-10s with the cubes fwf, you would th ink Van's would listen and consider that there may be another way of doing t hings that may be better. > > Bob > > Sent from my iPad > > On Nov 10, 2012, at 8:32 PM, "bob-tcw" wrote: > >> Fellow builders, >> >> Some of you may be aware that I=99ve seen some deviations in fuel p ressure and flow in cruise flight in my RV-10: I=99ve got to root ca use. >> >> After the past 10 months of investigation and discussions and general hea d scratching I finally have come to a conclusion. >> >> Executive summary: Don=99t mount the fuel flow sender in the tunne l per the plans! It has too much pressure drop and gets too warm in this lo cation, this can lead to vapor lock. The onset seen as deviations in fuel pressure and fuel flow. >> >> >> The full report can be downloaded at: >> >> http://tcwtech.com/Fuel%20flow%20write-up.pdf >> >> >> Bob Newman >> N541RV >> >> >> >> ========================= ========= >> ctric.com >> >www.buildersbooks.com >> uilthelp.com >> matronics.com/contribution >> ========================= ========= >> ://www.matronics.com/Navigator?RV10-List >> ========================= ========= >> cs.com >> ========================= ========= >> > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 3 _____________________________________ Time: 05:53:23 AM PST US Subject: RV10-List: Re: Problem with Fuel flow transducer in the tunnel From: "jkreidler" Great post Bob - thanks for sharing. One of the important factors to note about vapor lock is that the boiling point of fuel is considerably higher with higher pressure. So the fuel before the mechanical pump is at a much lower pressure and therefore has a much lower boiling point. This brings back memories of problems we used to have before moving our Flow Scan transducer to the location between the servo and spider as you did. We also saw our fuel pressure drop on long high climbs, we added a cooling shroud to the mechanical fuel pump. At some point we also moved the sensor, we no longer see fuel pressure drops. I think it is fair to say that we may have experienced the same issue as you had. We did not see this change 'fix' our LOP stumbles, but since we were not looking for this to effect our LOP issues I can not tell you if it made an improvement. I still wonder if the fuel in the lines between the spider and the injectors are vaporizing at the very low flows and low pressures. Bottom line, your data backs up your hypothesis, thanks for sharing. There are a lot of aircraft out there with the transducer running between the servo and the spider. The readings are more stable, and you have offered yet one more data point in support of moving the transducer out of the tunnel. Vans seems to reason that they do not like the sensor up front since it is in a hotter, higher vibration area. I wonder if either of these are actually fact, the tunnel is quite hot. When you directly attach a piece of aluminum to the hot bottom surface of the aircraft and then bolt the sensor tightly to that nice heat sink subjected to all of the high frequency vibrations of the airframe, I really don't know if it is any better off. The sensor between the servo and spider is suspended in air mounted between two hoses which I think would do a good job of dampening vibrations. I have NO data to say which location is higher in vibration or temperature. I can only say that both locations are used today, and I do not see reports of these sensors failing in either location. If you are still building you really need to ask yourself what the BENEFIT to mounting the sensor in the tunnel is. I struggle to see any downside to mounting the sensor between the servo and spider, especially after seeing Bob's well done data driven report. The issues are real, the solution is known, just my two cents worth - Jason -------- Jason Kreidler 4 Partner Build - Sheboygan Falls, WI Tony Kolar, Kyle Hokel, Wayne Elser, Jason Kreidler N44YH - Flying - #40617 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=387539#387539 ________________________________ Message 4 _____________________________________ Time: 06:07:00 AM PST US Subject: RV10-List: Re: Problem with Fuel flow transducer in the tunnel From: "bill.peyton" Bob, Thanks for the great post. I had the similar issues with another (certified) aircraft when the flow transducer (floscan) was installed between the electric and mechanical fuel pump. It is my belief that the transducers don't like to be on the suction side of the mechanical diaphragm pumps due to the pulsing of the pump. When we looked at the RV-10 plans it was clear to us that putting it on the output side of the mechanical pump was the correct way to go. We also have it mounted between the servo and the spider and it is working just fine. -------- Bill WA0SYV Aviation Partners, LLC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=387541#387541 ________________________________ Message 5 _____________________________________ Time: 06:36:03 AM PST US From: Pascal Subject: Re: RV10-List: Re: Problem with Fuel flow transducer in the tunnel I had the exact same thought, Bob is a smart guy so I take his hard work serious and have thought this through. I have had a psi issue maybe 4 times no real consistency on when however in 110 hours of flying. Here is my thought on moving 1 Dynon tells installers NOT to install cube FWF for the EMS install 2 Vans has theirs in the tunnel and told me to not put the cube there 3 it isn't broke The general and Tim both mentioned It only is an issue with the fuel pump on and even then not Big issue 3.2 hour flight yesterday, added 48.2 gallons when I returned because I was empty my computer said I would need 48.6, it was dark and I don't think I filled it to the top. Regardless close enough. I have no issues, not even with hot starts If it isn't an issue why all the work to move it? Good information however. Thanks Bob! On Nov 10, 2012, at 9:01 PM, "charliewaffles" wrote: > > Thanks for sharing your experience and the data. The charts and actual data are great to see. I don't doubt typos have fixed your problem, but I wonder if this is coincidental to the tunnel issue. Perhaps you can help me understand the following questions? > > 1) if moving the red cube out of the tunnel (amoung other things) resulted in no more problems, is your hyphothesis that the cube is heating up and causing vapor lock? > > 2) all of the other people that have posted about red cube issues in the tunnel have said the reporting of fuel consumption is high when the pump is on, but no one else has indicate the say pressure drop and flow increase relating to a cube in the tunnel. > > 3) is it possible insulating the lines and even the cube in the tunnel would do just as good of a job? Is any where mounted to the engine or the firewall hotsidemreally going to be cooler than the tunnel? > > 4) if the red cube heating in the tunnel caused the vapor lock, wouldnt that still occur when it was on the engine and exposed to heat there? > > 5) it sounds like several things wee changed at once and undoubtedly fixed your problem. How sure of you it was the red cube and not say a bend in a line, the routing or one of the other variables that were changed. > > I've gone back and forth on moving the red cube during my build. Most of the data and issues so far with the tunnel have been reporting issues, not performance related. If the cube IS causing vapor lock (or almost) and LOP is affected, then that is a great reason to move it. I just wonder if we have enough info yet to say that. > > Just my initial thoughts and perhaps you are onto something here. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=387531#387531 > > > > > > > > > > > ________________________________ Message 6 _____________________________________ Time: 06:38:55 AM PST US From: "bob-tcw" Subject: Re: RV10-List: Re: Problem with Fuel flow transducer in the tunnel I received a bunch of comments off-list as well as on-list. I'll try to summarize here for everyone. 1) My tunnel has always been insulated (on the bottom) since day 1 and comparing to what others reported early on about hot tunnels I always thought mine was relatively cool since in any operating condition I could easily and comfortably keep my hand on it. Also, my firewall is insulated on the engine side with koolmat silicone membrane. 2) I did change two things at once, I realize its not the absolutely scientific way to do an experiment, but given the work to get in and out of my tunnel, I had to do every thing I could in one shot. I moved the fuel cube and the I insulated the replacement line I installed from the electric fuel pump to the firewall bulkhead fitting. 3) Yes I used to see elevated fuel flow readings with the electric fuel pump on just like everyone else with the fuel cube in the tunnel. However, these high readings are totally an artifact of turbulence in the line caused by the fuel pump. Switching the fuel pump on and off had no noticeable effect on egt, so the fuel flow was definitely NOT actually changing. 4) The problem with the fuel cube is that of all the fittings in the system it has the most significant pressure drop for a given flow rate. I did dig into this extensively, the electric fuel pump in the OFF state and fuel cube each have a similar pressure drop, followed by the pressure drop associated with each elbow and each length of tubing. Each of these pressures drops moves the fuel closer to its vapor pressure level. Here's the engineering details: Avgas has a maximum reid vapor pressure of 49kPa @ 38 C or about 7.1 psi absolute pressure, a standard day at sea level has an absolute pressure of 14.7 psi, as we know, as we go up in altitude and/or up in temp the absolute pressure falls. When the absolute pressure meets the vapor pressure, the fuel begins to vaporize and bad things happen to fuel flow. So know if we go up to 11,000 ft and we raise the temp of the tunnel to 40 C which is nice comfortable temperature as detected by putting one's hand on the tunnel, we would have effectively a density altitude of 16,050 ft inside the tunnel as far as the fuel would know. So now converting the 16,050 ft to absolute pressure we get 7.9 psi. Therefore, to avoid vapor lock issues the total pressure drop at our flow rate of about 13 gph better be less than 0.8 psi. The fuel cube and the pump each are in the 0.15 to 0.25 psi range depending on flow rates and how you look at the charts I could dig up. So subtracting those two pressure drops from the absolute pressure we are down to pressure margin of maybe 0.3 or 0.4 psi for all other fittings, tubing and the selector valve. So clearly the best two things to do are to insulate everything possible from additional heating and remove any pressure drops you can from the suction side of the fuel system. The benefit to moving the fuel cube to the pressure side of the fuel system is now the 0.25 psi drop is subtracted off of the gauge and absolute pressure, so at 26 psi gauge for the same conditions above we would be at 33.9 psi absolute minus the 0.25 psi drop, which is completely inconsequential. If I missed any of the comments, please tee them up again. Bob Newman N541RV ________________________________ Message 7 _____________________________________ Time: 06:58:23 AM PST US Subject: RV10-List: Re: Problem with Fuel flow transducer in the tunnel From: "bill.peyton" Bob, In your calculation wouldn't you have to include the flow rate of the fuel and the OAT and the heat absorption of the fuel. Obviously the heat absorption would be different at various flow rates and would be at it maximum amount at 0 GPH. This would be more indicative of the fuel temp. in the lines during flight. While the tunnel may be at 40C the fuel will be at a much lower temp while it is flowing and should provide a more significant margin, assuming it is not 40C outside and the fuel has hot soaked to 40C! I too insulated my firewall and the floor of the tunnel with fibrefrax and fireproof black 1/2 foam on top of it. My tunnel is cool to the touch during flight with the heat off. I have not used the heat yet and will see how it behaves with the heat valve open. I also firesleeved the steel fuel line out of the pump -------- Bill WA0SYV Aviation Partners, LLC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=387544#387544 ________________________________ Message 8 _____________________________________ Time: 07:17:22 AM PST US Subject: Re: RV10-List: Re: Problem with Fuel flow transducer in the tunnel From: Kelly McMullen I agree that the sending unit NEEDS to be downstream of both fuel pumps. I think it is instructive to look at EI's install instructions for their fuel flow instrument, because they are the supplier of the red cube, that is STC approved on most engines. Either EI or Flowscan can be the manufacturer, but the install instructions are the same. Note that for ALL engines with fuel injection that do NOT have a return line to the fuel tank(that would not include purge lines), they specify locating the sending unit between the mechanical fuel pump and the fuel servo. The only time they specify between the fuel servo and the spider is for injected engines with a fuel return line. I don't believe anyone is using such a system on the IO-540. Van's location is directly contrary to EI's STC approved instructions. Such a deviation would not be approved on a certified aircraft. http://www.buy-ei.com/Information/II%20-%20FP-5.pdf On Sun, Nov 11, 2012 at 7:06 AM, bill.peyton wrote: > > Bob, > > When we looked at the RV-10 plans it was clear to us that putting it on > the output side of the mechanical pump was the correct way to go. We also > have it mounted between the servo and the spider and it is working just > fine. > > -------- > Bill > WA0SYV > Aviation Partners, LLC > > ________________________________ Message 9 _____________________________________ Time: 07:27:09 AM PST US Subject: Re: RV10-List: Re: Problem with Fuel flow transducer in the tunnel From: Kelly McMullen I just check my current Dynon Skyview install manual. It actually says location of the fuel sending unit, which is the EI FT-60 (they no longer supply the floscan.) They say the location is up to the builder, and that it is common for it to be between the electric and mechanical pumps. Their only recommendation with regard to the firewall is for the EMS unit, not the fuel flow sending unit. I agree with those that have concern as to the response of the sending unit to suction of the mechanical pump. Given that EI is the manufacturer, I would say best performance will be obtained following their guidance to install between mechanical pump and fuel servo. On Sun, Nov 11, 2012 at 7:35 AM, Pascal wrote: > > > Here is my thought on moving > 1 Dynon tells installers NOT to install cube FWF for the EMS install > 2 Vans has theirs in the tunnel and told > me to not put the cube there > 3 it isn't broke > > The general and Tim both mentioned > It only is an issue with the fuel pump on and even then not Big issue > > 3.2 hour flight yesterday, added 48.2 gallons when I returned because I > was empty my computer said I would need > 48.6, it was dark and I don't think I filled it to the top. Regardless > close enough. > > I have no issues, not even with hot starts > If it isn't an issue why all the work to move it? > ________________________________ Message 10 ____________________________________ Time: 08:25:33 AM PST US From: Ed Godfrey Subject: Re: RV10-List: Opinion please ________________________________ Message 11 ____________________________________ Time: 08:37:22 AM PST US From: Ed Godfrey Subject: RV10-List: Opinions please Well, I have applied flame to it and also tried sanding it to see if the edges show. Both were negative, so I will continue sanding it and filling where necessary. Thanks to all for your advice and suggestions. Ed Godfrey 40717 On 11/3/2012 6:49 PM, Dave Saylor wrote: Bill's right, that's most likely an area that never had peel-ply over it. If it does turn out to still have some on it, you should be able to get ahold of an edge and tear it off. In that area, it wouldn't hurt to just leave some peel ply there but that's not really the best practice. It looks to me like it's just plain glass though. I'd sand it with some 80 grit and finish it however you like. That's another way to find the peel ply--if the edges ball up when you sand it, you'll know it's peel-ply. I painted some of those hard-to-finish areas with truck bed liner. Turned out pretty well. Dave Saylor 831-750-0284 CL ________________________________ Message 12 ____________________________________ Time: 08:51:48 AM PST US From: davidsoutpost@comcast.net Subject: Re: RV10-List: Opinions please Its just glass that wasn't peel plied. You would immediately see the fibers of the peel ply show up white after you hit it with some course 36 or 40 sand paper. Clean the area up to your satisfaction and move on. David Clifford RV-10 Builder Howell, MI ----- Original Message ----- From: "Ed Godfrey" Sent: Sunday, November 11, 2012 11:37:00 AM Subject: RV10-List: Opinions please Well, I have applied flame to it and also tried sanding it to see if the edges show. Both were negative, so I will continue sanding it and filling where necessary. Thanks to all for your advice and suggestions. Ed Godfrey 40717 On 11/3/2012 6:49 PM, Dave Saylor wrote: Bill's right, that's most likely an area that never had peel-ply over it. If it does turn out to still have some on it, you should be able to get ahold of an edge and tear it off. In that area, it wouldn't hurt to just leave some peel ply there but that's not really the best practice. It looks to me like it's just plain glass though. I'd sand it with some 80 grit and finish it however you like. That's another way to find the peel ply--if the edges ball up when you sand it, you'll know it's peel-ply. I painted some of those hard-to-finish areas with truck bed liner. Turned out pretty well. Dave Saylor 831-750-0284 CL ________________________________ Message 13 ____________________________________ Time: 09:08:31 AM PST US From: "J. R. (Dick) Dial" Subject: RV10-List: rudder trim RV-10 I have a new RV-10 trim kit from Aerosports Products in the box unopened I will sell for $195.oo, I will pay freight in USA. I built and fly an RV6 and won this in a drawing at an RV Fly-In. Contact: jrdial@hal-pc.org ________________________________ Message 14 ____________________________________ Time: 11:37:26 AM PST US Subject: Re: RV10-List: Problem with Fuel flow transducer in the tunnel From: Fred Williams Bob, Thanks for your excellent write up. I have a very similar set up and have occasionally noted the fluctuations in fuel flow just as you have described. I also, have not been able to run LOP secondary to the engine running too rough. I don't feel that I have a "hot tunnel" either. Does anybody know if the flow is an optical pick up or is there a rotor sensing the fuel flow? I just started my condition inspection and am seriously thinking about moving the transducer. Might as well do it before I have a real problem in flight or on take off. Did you use "hard lines" or did you go with the flex lines and fire sleeve them in the tunnel? Thanks Fred Williams 500 hrs and 4 years. Sent from my iPad ________________________________ Message 15 ____________________________________ Time: 12:07:20 PM PST US Subject: RV10-List: RE: Elevator skin From: Terry Moushon Steve, i just finished my elevators today for the RV 10....so I am new at this. Couple points to this. First, the elevator skin goes on top so that you have access to four key rivets on the front spar and can buck the two rivets on the upper skin. After attaching the rib tip assembly you should close the top skin first because the bottom skin uses two pop rivets that don't requiring bucking. RV 10 builders.... Short note of thanks. I posted a note a couple months ago asking for help with a test flight. Not only did I recieve quite a few responses... Dick Sipp and his wife Vicky stopped by on their way home to Michigan at the end of September and gave me and my wife a wonderful flight.... I ordered the 10 the next day. Most of my questions to date have been answered by the great notes from Matronics as well as the great tips in the building process found on various web sites. In my build I alumiprep, alodine and two part epoxy paint... I installed a Ray Allen wire in the rudder and cut in an access plat for future use.... ALL of these great ideas coming from this team...so THANK YOU. I hope to learn more...and give back some day... Again, my sincere thanks! My call sign changed from " builder want-to-be". It is now builder #41393. Terry. :) ________________________________ Message 16 ____________________________________ Time: 01:10:03 PM PST US From: "Bob Leffler" Subject: RE: RV10-List: rudder trim RV-10 Geoff's rudder trim can be adapted to other model RV's. Call Geoff for details. bob From: owner-rv10-list-server@matronics.com [mailto:owner-rv10-list-server@matronics.com] On Behalf Of J. R. (Dick) Dial Sent: Sunday, November 11, 2012 12:08 PM Subject: RV10-List: rudder trim RV-10 I have a new RV-10 trim kit from Aerosports Products in the box unopened I will sell for $195.oo, I will pay freight in USA. I built and fly an RV6 and won this in a drawing at an RV Fly-In. Contact: jrdial@hal-pc.org ________________________________ Message 17 ____________________________________ Time: 01:36:06 PM PST US Subject: Re: RV10-List: Problem with Fuel flow transducer in the tunnel From: Jesse Saint It has a rotor. Jesse Saint I-TEC, Inc. jesse@itecusa.org www.itecusa.org www.mavericklsa.com C: 352-427-0285 O: 352-465-4545 F: 815-377-3694 Sent from my iPhone On Nov 11, 2012, at 2:36 PM, Fred Williams wrote: > > Bob, > > Thanks for your excellent write up. I have a very similar set up and have occasionally noted the fluctuations in fuel flow just as you have described. I also, have not been able to run LOP secondary to the engine running too rough. I don't feel that I have a "hot tunnel" either. Does anybody know if the flow is an optical pick up or is there a rotor sensing the fuel flow? > > I just started my condition inspection and am seriously thinking about moving the transducer. Might as well do it before I have a real problem in flight or on take off. > > Did you use "hard lines" or did you go with the flex lines and fire sleeve them in the tunnel? > > > Thanks > > Fred Williams > 500 hrs and 4 years. > > Sent from my iPad > > > > ________________________________ Message 18 ____________________________________ Time: 01:52:24 PM PST US From: "bob-tcw" Subject: Re: RV10-List: Re: Problem with Fuel flow transducer in the tunnel Bill, You are correct about the flow rate and OAT temp, however, there's a lot of aluminum tubing, fittings, the pump and fuel cube all collecting the heat of the tunnel and delivering it to the fuel. Without doing elaborate measurements, the answer lies somewhere between the OAT temp and the tunnel temp. The issue I saw was definitely correlated with reduced fuel flow rates, as soon as I increased the flow rate from 12 to about 13 gph the issue went away. Bob -----Original Message----- From: bill.peyton Sent: Sunday, November 11, 2012 9:57 AM Subject: RV10-List: Re: Problem with Fuel flow transducer in the tunnel Bob, In your calculation wouldn't you have to include the flow rate of the fuel and the OAT and the heat absorption of the fuel. Obviously the heat absorption would be different at various flow rates and would be at it maximum amount at 0 GPH. This would be more indicative of the fuel temp. in the lines during flight. While the tunnel may be at 40C the fuel will be at a much lower temp while it is flowing and should provide a more significant margin, assuming it is not 40C outside and the fuel has hot soaked to 40C! I too insulated my firewall and the floor of the tunnel with fibrefrax and fireproof black 1/2 foam on top of it. My tunnel is cool to the touch during flight with the heat off. I have not used the heat yet and will see how it behaves with the heat valve open. I also firesleeved the steel fuel line out of the pump -------- Bill WA0SYV Aviation Partners, LLC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=387544#387544 ________________________________ Message 19 ____________________________________ Time: 01:55:00 PM PST US From: "bob-tcw" Subject: Re: RV10-List: Problem with Fuel flow transducer in the tunnel Fred, The red fuel cube has a little turbine wheel that spins on some type of jeweled bearing, I suspect that the turbine then acts on a hall effect sensor or an optical sensor. The new fuel line I installed from the electric pump to the bulkhead fitting was a fire sleeved flex line. Bob -----Original Message----- From: Fred Williams Sent: Sunday, November 11, 2012 2:36 PM Subject: Re: RV10-List: Problem with Fuel flow transducer in the tunnel Bob, Thanks for your excellent write up. I have a very similar set up and have occasionally noted the fluctuations in fuel flow just as you have described. I also, have not been able to run LOP secondary to the engine running too rough. I don't feel that I have a "hot tunnel" either. Does anybody know if the flow is an optical pick up or is there a rotor sensing the fuel flow? I just started my condition inspection and am seriously thinking about moving the transducer. Might as well do it before I have a real problem in flight or on take off. Did you use "hard lines" or did you go with the flex lines and fire sleeve them in the tunnel? Thanks Fred Williams 500 hrs and 4 years. Sent from my iPad ________________________________ Message 20 ____________________________________ Time: 03:35:01 PM PST US Subject: RV10-List: Re: Problem with Fuel flow transducer in the tunnel From: "billz" Bob, Thank you for the excellent analysis. 1. Bob, What did you use for insulation on the fuel lines in the tunnel?? 2. Has anyone used insulation on the heat runs in the tunnel? I'm thinking this adds a significant amount of heat (with uninsulated SCAT) when the heat is turned on. If so, what type of insulation did you use?? FWIW, Every fuel flow sender installation I've seen in certified aircraft has had the sensor mounted ahead of the firewall and usually between the fuel servo and flow divider. Great discussion. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=387569#387569 ________________________________ Message 21 ____________________________________ Time: 05:14:57 PM PST US From: "Carl Froehlich" Subject: RV10-List: Rigging thoughts 60 hours on the RV-10 and one long cross country. Here are some recent tweaks that I=92ve incorporated: - Added a .063=94 shim under the forward HS spar. This moved the elevators to a better trail position in cruise. I had a .040=94 shim in for 10 hours or so. It helped but was not quite enough. Even with this larger shim I have more nose up trim authority than I will ever need. With anything other than forward CG conditions however the elevators are still slightly trailing edge down. This calls for a larger shim but the .063=94 is about all I want to do for now as more may force an empennage fairing adjustment and/or re-hanging the rudder. For those wondering, my W&B is typical of other RV-10s. - Right wing slightly heavy. Not so bad that aileron trim would not fix, but not right. After some careful measurements I found the right aileron inboard hinge placed the aileron slightly high (as compared to the outboard hinge and the left aileron). I lowered the inboard side of the aileron .032=94 or so and this resolved the wing heavy issue. - Ball not centered. I chased my tail on this for some time. With the wheel pants and gear leg fairing off the ball is dead center. Various tweaks on the pants and fairings either had the ball =BD out left or right. After several tries it is now dead center (and just finished final pant and fairing paint today). Some take-aways for those working this issue: o The fairing adjustments are far more critical than the wheel pants at affecting the ball. Set the wheel pants as close as possible, then make all adjustments to the fairings after that. o The Van=92s instructions lead you to think you can mount the wheel pants with the plane on the gear. I don=92t recommend this. o You can never be too accurate setting up to check the fairing rig. A 1/16=94 move of the fairings trailing edge equals =BC ball or so. - Don=92t paint the pants or fairings until after you are flying. - Add the =93reinforcement glass=94 to the nose gear wheel pant (there was a recent thread on this). After mine cracked, I added two layers of carbon fiber to the inside, ground out the crack and filled it in with flox, sanded then two layers of regular glass on the outside over the crack. This was followed by the normal =93micro-balloon and sand until you puke=94 routine. Rigging does matter. I notice a measureable gain in top and cruise speeds after these tweaks. At one time while chasing the ball I had the wheel pants way out of alignment (before I figured out the fairings are the real drivers). This caused and easy 5 knot loss. Carl ________________________________ Message 22 ____________________________________ Time: 05:22:33 PM PST US Subject: Re: RV10-List: Elevator Rib Tip Assembly From: Ed Kranz The main skin is outside of the tip rib skin. I've got a lot of pictures showing where everything goes... inside and out here: https://picasaweb.google.com/lh/photo/LsXUR2H2FM1my_ggJ8WALNMTjNZETYmyPJy0liipFm0?feat=directlink On Sat, Nov 10, 2012 at 10:49 AM, Gordon Anderson wrote: > Hi Steve, > > I believe Figure 4 page 9-15 shows the main skin on the outside, which > worked fine for me. > > Gordon Anderson > 41015 Switzerland > > On Nov 10, 2012, at 1:25 PM, Steve Farner wrote: > > I'm trying to determine whether the Rib Tip Assembly is attached over or > under the main elevator skins. Does anyone recall which skin is supposed > to be on top? I believe the main skin is on top, but the picture in the > manual appears to show the rib tip skin on top. > > Steve Farner > > * > > href="http://www.aeroelectric.com">www.aeroelectric.com > href="http://www.buildersbooks.com">www.buildersbooks.com > href="http://www.homebuilthelp.com">www.homebuilthelp.com > href="http://www.matronics.com/contribution">http://www.matronics.com/contribution > href="http://www.matronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List > href="http://forums.matronics.com">http://forums.matronics.com > * > > > * > > * > > ________________________________ Message 23 ____________________________________ Time: 05:24:55 PM PST US Subject: Re: RV10-List: Elevator Rib Tip Assembly From: Ed Kranz Sorry. That link was to an individual picture. This link should take you to the album. The elevator assembly is abut half way down. https://picasaweb.google.com/104915858356518723094/RV102Empennage On Sun, Nov 11, 2012 at 7:22 PM, Ed Kranz wrote: > The main skin is outside of the tip rib skin. I've got a lot of pictures > showing where everything goes... inside and out here: > https://picasaweb.google.com/lh/photo/LsXUR2H2FM1my_ggJ8WALNMTjNZETYmyPJy0liipFm0?feat=directlink > > > On Sat, Nov 10, 2012 at 10:49 AM, Gordon Anderson wrote: > >> Hi Steve, >> >> I believe Figure 4 page 9-15 shows the main skin on the outside, which >> worked fine for me. >> >> Gordon Anderson >> 41015 Switzerland >> >> On Nov 10, 2012, at 1:25 PM, Steve Farner wrote: >> >> I'm trying to determine whether the Rib Tip Assembly is attached over or >> under the main elevator skins. Does anyone recall which skin is supposed >> to be on top? I believe the main skin is on top, but the picture in the >> manual appears to show the rib tip skin on top. >> >> Steve Farner >> >> * >> >> href="http://www.aeroelectric.com">www.aeroelectric.com >> href="http://www.buildersbooks.com">www.buildersbooks.com >> href="http://www.homebuilthelp.com">www.homebuilthelp.com >> href="http://www.matronics.com/contribution">http://www.matronics.com/contribution >> href="http://www.matronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List >> href="http://forums.matronics.com">http://forums.matronics.com >> * >> >> >> >> * >> >> * >> >> > ________________________________ Message 24 ____________________________________ Time: 06:12:58 PM PST US Subject: Re: RV10-List: Red Cube FWF install From: Rick Lark Sean, how did you, or where did you get the fire sleeve to cover the transducer? Thx, Rick #40956 Southampton, Ont On Fri, Nov 9, 2012 at 6:59 PM, Seano wrote: > Myron, > > Here is a pic of mine. 280 hours with no problems. I fireslleved mine per > directions but I didn't follow the statement: Do not attach the transducer > directly to the engine...... > > Here is some notes from the installation manual. > > > Fuel Flow Transducer Notes > . NEVER blow through the transducer. Keep the yellow caps on until it is > installed. > . The fuel flow transducer(s) should be installed in a straight section of > your fuel line. (6 straight inches on each side is desirable). > . The fuel line should not drop down after exiting the transducer. > . The wires MUST NOT come out of the bottom of transducer. Wires pointing > up is the best . > . When assembling fittings into the 1/4" NPT inlet and outlet ports do not > exceed a torque value of 25 ft.-lbs. > . Do not use Teflon tape in an aircraft fuel system. Use "Fuel Lube/Ez > Turn Lubricant" > . The transducer should be mounted down stream of a fuel filter. > . Do not attach the transducer directly to the engine to avoid excessive > vibration. > . Do not mount the transducer near the exhaust systems or other hot engine > components. > . If the transducer is in the engine compartment, it should be covered in > fire sleeve to protect it from excessive heat. > . The transducer wires may be trimmed any desired length > Possible Transducer Placement Locations: > 1. Between the auxiliary electric boost pump and the engines mechanical > fuel pump. > 2. Between fuel injection servo and the distribution block. > 3. Between the Engine driven pump and the Carburetor > Note: If your engine is equipped with a fuel return line from the > carburetor back to the fuel tank you will need to install two flow > transducers. > One in the feed line from the fuel pump to the carburetor and one in the > return line from the carburetor back to the fuel tank. This applies to > certain Continental engines and Rotax 912(ULS) and 914 engines. > > > ----- Original Message ----- From: "woxofswa" > To: > Sent: Friday, November 09, 2012 11:27 AM > Subject: RV10-List: Red Cube FWF install > > >> >> Anyone be so kind as to post some pix on their firewall forward red cube >> installation? >> >> Thanks in advance. >> >> -------- >> Myron Nelson >> Mesa, AZ >> Emp completed, QB wings completed, legacy build fuse in mostly done, >> finishing kit in progress. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/**viewtopic.php?p=387382#387382 >> >> >> >> >> >> >> >> >> >> >> ________________________________ Message 25 ____________________________________ Time: 08:04:43 PM PST US From: "Seano" Subject: Re: RV10-List: Red Cube FWF install Rick, I bought mine from Aircraft Spruce. The first link is what I clicked on and then onto the proper size, which I can't currently remember. I would just measure a rough circumference. The second link is a new one for me. I would have ordered this if it was available when I installed mine. http://www.aircraftspruce.com/catalog/appages/stratofs.php?clickkey=411 8 http://www.aircraftspruce.com/catalog/appages/gbfireslvft.php?clickkey= 4118 I cut the bolt holes through the firesleeve and pushed it on then stuck the bolts through both. I then connected the fuel lines. As you can see I mounted mine to the engine which the instructions say NOT to do for vibration. ----- Original Message ----- From: Rick Lark To: rv10-list@matronics.com Sent: Sunday, November 11, 2012 7:12 PM Subject: Re: RV10-List: Red Cube FWF install Sean, how did you, or where did you get the fire sleeve to cover the transducer? Thx, Rick #40956 Southampton, Ont On Fri, Nov 9, 2012 at 6:59 PM, Seano wrote: Myron, Here is a pic of mine. 280 hours with no problems. I fireslleved mine per directions but I didn't follow the statement: Do not attach the transducer directly to the engine...... Here is some notes from the installation manual. Fuel Flow Transducer Notes . NEVER blow through the transducer. Keep the yellow caps on until it is installed. . The fuel flow transducer(s) should be installed in a straight section of your fuel line. (6 straight inches on each side is desirable). . The fuel line should not drop down after exiting the transducer. . The wires MUST NOT come out of the bottom of transducer. Wires pointing up is the best . . When assembling fittings into the 1/4" NPT inlet and outlet ports do not exceed a torque value of 25 ft.-lbs. . Do not use Teflon tape in an aircraft fuel system. Use "Fuel Lube/Ez Turn Lubricant" . The transducer should be mounted down stream of a fuel filter. . Do not attach the transducer directly to the engine to avoid excessive vibration. . Do not mount the transducer near the exhaust systems or other hot engine components. . If the transducer is in the engine compartment, it should be covered in fire sleeve to protect it from excessive heat. . The transducer wires may be trimmed any desired length Possible Transducer Placement Locations: 1. Between the auxiliary electric boost pump and the engines mechanical fuel pump. 2. Between fuel injection servo and the distribution block. 3. Between the Engine driven pump and the Carburetor Note: If your engine is equipped with a fuel return line from the carburetor back to the fuel tank you will need to install two flow transducers. One in the feed line from the fuel pump to the carburetor and one in the return line from the carburetor back to the fuel tank. This applies to certain Continental engines and Rotax 912(ULS) and 914 engines. ----- Original Message ----- From: "woxofswa" To: Sent: Friday, November 09, 2012 11:27 AM Subject: RV10-List: Red Cube FWF install Anyone be so kind as to post some pix on their firewall forward red cube installation? Thanks in advance. -------- Myron Nelson Mesa, AZ Emp completed, QB wings completed, legacy build fuse in mostly done, finishing kit in progress. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=387382#387382 ________________________________ Message 26 ____________________________________ Time: 08:30:22 PM PST US Subject: RV10-List: Re: Problem with Fuel flow transducer in the tunnel From: "rv10flyer" My red cube is in the tunnel and has worked great for 95 hours from -10 to 105F OAT's. I am within .5 gallons at every fuel up. I run boost pump until 1000' agl and have taken off with pump off flowing 25.5 gph. I occasionally see fuel pressure drop about 3-5 psi during a 115-120 kt climb to 10500-13500'. The engine did not show any signs of roughness. If I am running cabin heat my fuel temp is much lower and still provides plenty of margin. If I was building again I would intall it fwf, but will not change it as long as it is working properly. -------- Wayne Gillispie 12/01/2011 TT= 95 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=387586#387586 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv10-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV10-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/rv10-list Browse Digests http://www.matronics.com/digest/rv10-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.