A64Pilot Posted February 17 Report Posted February 17 Heating air thereby increasing pressure which can be turned into velocity can be very significant. In WWII some water cooled airplanes used this waste heat to generate thrust and significantly increase their speed, probably the P-51 did this to greatest effect, but the Spitfire and Hurricane did it first I think. it’s called the Meredith effect. https://en.wikipedia.org/wiki/Meredith_effect#:~:text=The Meredith effect is a,hot air in the duct. 1 Quote
A64Pilot Posted February 17 Report Posted February 17 My opinion is the oil cooler was relocated for two reasons. First nearly everybody else locates it like it is in the J, it works well there, and secondly not having that structure out in front of the airplane is less drag. I can’t get the oil temp in my J to even run in the middle of the green, it’s always low. Quote
Ragsf15e Posted February 18 Report Posted February 18 4 hours ago, Shadrach said: Louvers likely meant there was a RayJay turbo underneath. If memory serves, my 67 F has an opening above #3 that serves as a blast tube for the accessories. There is an opening above #4 that feeds 1” SCAT that cools the mechanical fuel pump. The fresh air intake for the heat exchanger is underneath cylinder #2. It gets a direct supply of ram air but it will put some heat into the cabin from prop wash alone. I’ve always wondered how the ARI lower cowl enclosure works with the heat intake in front of #2; It seems to block direct airflow. I wondering if that affecting @Ragsf15e heat output? I’ve got the lasar one but it looks similar. The air intake is set back from the cowl closure far enough that it still seems to get solid air pressure. 1 Quote
Echo Posted February 18 Report Posted February 18 I really look forward to having the edm installed as my cylinder temps in climb with a J cowl (with turbo baffles) on my E, as well as oil temps have been surprisingly low compared to my first E with lower cowl closure and forward oil cooler location. I am a 120mph cruise climber. I have NOT been opening cowl flaps in climb as temps have been under 350. Just loving the J cowl on my E… Quote
Ragsf15e Posted February 18 Report Posted February 18 38 minutes ago, Echo said: I really look forward to having the edm installed as my cylinder temps in climb with a J cowl (with turbo baffles) on my E, as well as oil temps have been surprisingly low compared to my first E with lower cowl closure and forward oil cooler location. I am a 120mph cruise climber. I have NOT been opening cowl flaps in climb as temps have been under 350. Just loving the J cowl on my E… I actually wish the factory could economically build j cowls and outfit Es and Fs. No intake boot, even cooling and speed increase could make it popular. 3 Quote
Ragsf15e Posted February 23 Report Posted February 23 On 2/14/2024 at 12:10 PM, Shadrach said: If a 180hp C172 will out climb your airplane than something odd is going on with the loading comparison, or there is a problem with your plane. I have lots of time in 172s I don’t think any of them will out climb my plane to 10k including the XP. In response to your claims, I posted the closest thing I could to verifiable, 3rd party data showing a climb from 700’ to 10000’ in 8mins 12 seconds for an average of >1100fps. Crickets. Maybe it’s just that the Mooneys you’ve flown are tubby in the weight department. Perhaps there are other factors. But your assertion that they don’t climb well is not founded in actual numbers. Pound for pound they are top of class climbers and more useable above 8k than most other 200hp birds. I did my high performance checkout in a P-ponk C180K. It did not feel high performance at all coming from the little 200hp Mooney I flew right before the checkout. I tried to match your climb today, but no dice. Maybe your F climbs better than mine, or maybe there’s something else going on. 2c at takeoff, 2000’ field elevation. 9:50 to 10k. So ~815fpm. Still not bad. I was ~510lbs shy of mgw. Maybe takeoff, acceleration and cleaning up added more time but it seemed quick. 1 Quote
Shadrach Posted February 24 Report Posted February 24 3 hours ago, Ragsf15e said: I tried to match your climb today, but no dice. Maybe your F climbs better than mine, or maybe there’s something else going on. 2c at takeoff, 2000’ field elevation. 9:50 to 10k. So ~815fpm. Still not bad. I was ~510lbs shy of mgw. Maybe takeoff, acceleration and cleaning up added more time but it seemed quick. To be honest, I did not time it in the plane. Perhaps the time stamp data on ADSB exchange is incorrect. I will say that the calculation surprised me. That being said at light weights, indicated rates in the 1300-1500 range are not uncommon for the first few minutes. I’ll try again in the next week or so. 1 Quote
Ragsf15e Posted February 24 Report Posted February 24 1 hour ago, Shadrach said: To be honest, I did not time it in the plane. Perhaps the time stamp data on ADSB exchange is incorrect. I will say that the calculation surprised me. That being said at light weights, indicated rates in the 1300-1500 range are not uncommon for the first few minutes. I’ll try again in the next week or so. I’m interested in what you get as you’d think they’d be closer. Mine did indicate a vsi approximately what I calculated. I held 110mph (poh Vy) the whole time. I guess I should have slowed to ~100 by 10,000’. I had almost full tanks, me, and some random gear. The only time I see greater than 1000fpm vsi is taking off with maybe 20gallons and very cold. Quote
Shadrach Posted February 24 Report Posted February 24 On 2/23/2024 at 9:38 PM, Ragsf15e said: I’m interested in what you get as you’d think they’d be closer. Mine did indicate a vsi approximately what I calculated. I held 110mph (poh Vy) the whole time. I guess I should have slowed to ~100 by 10,000’. I had almost full tanks, me, and some random gear. The only time I see greater than 1000fpm vsi is taking off with maybe 20gallons and very cold. A few things may be at play. First I think that the POH is off. Norman @testwest calculated Vy for a 2740lb J model at 86kts/99mph. Second, Vy decreases with weight. So flying book numbers for MGW is leaving some ROC on the table. For max performance, I typically shoot for 95-100MIAS Calculating the numbers out using book Vy, your were still fast for your weight at 113mias. 2230/2740= .813 √.813=.902 .902*113= 102mph calculated Vy at 2230lbs I pulled out some random flights and calculated initial ROC. These were not all conducted Vy. But they are all solo flights, so 2100ish lbs. July 3rd flight - Weather 11:53Z 83°F DP 53°F RH 36 % 29.31inhg Field DA 3249’ 825’ to 2825’ = 2000’ ascent in 1:42 for an average ROC of 1176fpm. Jan 24 flight - Weather 1853Z 34°F DP 17°F RH 50% 29.04inHg Field DA 254’ 1450’ to 3300’ = 1850’ ascent in 1:32 for an average ROC OF 1206fpm Dec 15 flight Weather 1763Z 46°F DP 34°F RH 63% 29.73 inHg field DA 308’ 825’-3825’ = 3000’ ascent in 2:09 for an average ROC 1395fpm 2 Quote
Ragsf15e Posted February 24 Report Posted February 24 4 minutes ago, Shadrach said: A few things may be at play. First I think that the POH is off. Norman @testwest calculated Vy for 2740lb J at 86kts/99mph. Second, Vy decreases with weight. So flying book numbers for MGW is leaving some ROC on the table. For max performance, I typically shoot for 95-100MIAS Calculating the numbers out using book Vy, your were still fast for your weight at 113. 2230/2740= .813 √.813=.902 .902*113= 102mph calculated Vy at 2230lbs I pulled out some random flights and calculated initial ROC. These were not all conducted Vy. But they are all solo flights, so 2100ish lbs. July 3rd flight 825’ to 2825’ = 2000’ ascent in 1:42 for an average ROC of 1176fpm Jan 1 flight 1450’ to 3300’ = 1850’ ascent in 1:32 for an average ROC OF 1206fpm Dec 15 flight 825’-3825’ = 3000’ ascent in 2:09 for an average ROC 1395fpm Next time I go fly I’ll try 100-95mph and see what I get. My engine is older but very smooth and produces consistent cruise speeds. The gear tuck up nicely. Now I’m curious… Quote
Shadrach Posted February 25 Report Posted February 25 On 2/24/2024 at 12:48 AM, Ragsf15e said: Next time I go fly I’ll try 100-95mph and see what I get. My engine is older but very smooth and produces consistent cruise speeds. The gear tuck up nicely. Now I’m curious… I looked at your flight on ADSB exchange and the data reflect performance consistent with your claims. I was inspired to do this because after using historic weather to calculate DA for my flights (added to my last post), the numbers, adjusted for weight seem to be right at or slightly better than book. Particularly the July numbers. I am very curious about what’s behind this disparity. It’s either a data issue (seems unlikely), a climb profile issue or some other unknown. 2 Quote
Ragsf15e Posted February 25 Report Posted February 25 1 hour ago, Shadrach said: I looked at your flight on ADSB exchange and the data reflect performance consistent with your claims. I was inspired to do this because after using historic weather to calculate DA for my flights (added to my last post), the numbers, adjusted for weight seem to be right at or slightly better than book. Particularly the July numbers. I am very curious about what’s behind this disparity. It’s either a data issue (seems unlikely), a climb profile issue or some other unknown. I agree. I’d like to know as well. I’m going to try the different Vy next time out. Quote
pagirard Posted March 4 Author Report Posted March 4 Thanks everyone for your time and the great responses. I have now modified my climb procedure (full rich and full throttle on TO) and starting to lean for 1250degF EGT starting at 5000'. I also adjusted my climb speed to 105kts IAS have a much better CGH and climb performance. Also learned a lot about the prop and prop governor limit ! Thanks a lot everyone. 2 Quote
Ragsf15e Posted March 7 Report Posted March 7 (edited) On 2/25/2024 at 8:09 AM, Shadrach said: I looked at your flight on ADSB exchange and the data reflect performance consistent with your claims. I was inspired to do this because after using historic weather to calculate DA for my flights (added to my last post), the numbers, adjusted for weight seem to be right at or slightly better than book. Particularly the July numbers. I am very curious about what’s behind this disparity. It’s either a data issue (seems unlikely), a climb profile issue or some other unknown. I tried it again today using 100mph initially and slowing to 95mph by 10,000’. It was 2c for a DA of ~800’ at takeoff, weight was 2200lbs, ram on at ~1000’. Average to 10k (2,000-10,000’) was 955fpm. Average all the way to 12k was 875fpm. Looking through my poh, I averaged their climb numbers from 2-10k at 2300lbs and get 922fpm. I slightly beat that but I’m 100lbs lighter and a little cooler temp. I’m pretty darn close to book. I did see ~1250fpm initially. CHTs weren’t a problem on the cold day - All ~350, but deck angle makes clearing difficult. Your airplane seems to be a solid climber based on your data. It beats book numbers pretty well. Based on poh, SL to 10k should be an average of about 990fpm. Edited March 7 by Ragsf15e 2 Quote
Shadrach Posted March 7 Report Posted March 7 2 hours ago, Ragsf15e said: I tried it again today using 100mph initially and slowing to 95mph by 10,000’. It was 2c for a DA of ~800’ at takeoff, weight was 2200lbs, ram on at ~1000’. Average to 10k (2,000-10,000’) was 955fpm. Average all the way to 12k was 875fpm. Looking through my poh, I averaged their climb numbers from 2-10k at 2300lbs and get 922fpm. I slightly beat that but I’m 100lbs lighter and a little cooler temp. I’m pretty darn close to book. I did see ~1250fpm initially. CHTs weren’t a problem on the cold day - All ~350, but deck angle makes clearing difficult. Your airplane seems to be a solid climber based on your data. It beats book numbers pretty well. Based on poh, SL to 10k should be an average of about 990fpm. That’s more like it! I think it is the cumulative effect of many small things. It’s light (1681lbs). With me and half tanks I’m ~650lbs under gross. The engine runs very strong. It will indicate well into the yellow arc (152kts) down low. It still has the factory rigging. It was a dealer demonstrator for the first 100hrs of its life. I wonder if extra care was taken to maximize performance. Factory paint is not the best, but it flies so well, I’m half afraid to mess with anything. I’ve been too swamped to do any flight testing. Hopefully next week. Curious to see the extra 60rpm affect climb noticeably 2 Quote
Ragsf15e Posted March 8 Report Posted March 8 1 hour ago, Shadrach said: That’s more like it! I think it is the cumulative of many small things. It’s light (1681lbs). With me and half tanks I’m ~650lbs under gross. The engine runs very strong. It will indicate well into the yellow arc (152kts) down low. It still has the factory rigging. It was a dealer demonstrator for the first 100hrs of its life. I wonder if extra care was taken to maximize performance. Factory paint is not the best, but it flies so well, I’m half afraid to mess with anything. I’ve been too swamped to do any flight testing. Hopefully next week. Curious to see the extra 60rpm affect climb noticeably I do think you’re right, little things add up. I was surprised how much the difference was with the 100mph climb vs the book Vy which was close to 110mph that I flew last time. 1 Quote
carusoam Posted March 8 Report Posted March 8 (edited) Hey gents..! Some things we learn from the modern NA Mooneys… that most likely apply to the older Mooneys as well. both old and new were built for nearly the same mission… just, the newer models have more development time collected through the decades… 1) the Ovation has the NA IO550… 2) it’s EGT gauge is calibrated with actual numbers. Mounted in a specific location where there is a confluence of three exhaust streams on one side of the engine… 3) the climb procedure includes leaning in the climb… 4) the EGT is maintained by using a blue box on the EGT gauge, white for the G1000… 5) the box or arc is 100°F wide, and runs from 200-300°F ROP. 6) adjustments are made as needed… 7) the needle falls safely out the bottom, colder… as altitude increases. 8) airflow through a modern cowl was highly studied… 9) My M20C’s cowl met basic requirements of the day… some of its airflow did exit the front of the cowl. Every now and then you could see where an oil drip would show signs of its escape… out the front. 10) its tach also suffered by being mismarked… some things changed over decades of knowledge… Red arcs became yellow by rule change… the avoidance arc was changed, and remarked, or added, using a piece of tape on the lens… 11) These important arcs only apply to the engine/prop combination that came with the plane…Updated markings can be put on the tach for a small charge at an instrument shop… 12) if you change the prop or the engine… make sure the markings are appropriate… the yellow arc helps keep the pilot from operating in a zone where harmonic vibrations can break engine mount welds… harmonics can’t be felt by the pilot, because the usual vibrations feel the same to even the best calibrated buttock… The M20C only used four bolts to hold the engine to the firewall… I have the experience of losing two welds, that left the engine holding on by three bolts instead of four… 13) The POH is a great resource of info… and so are the STCs that come with a new prop. 14) for a great reference, get a copy of the latest POH published for your model… especially for the older models that only got owners manuals… 15) Vx, Vy, and cruise climb are very similar for all Mooneys… the heavier ones are marked in kias, lighter are in mias… 16) climb rate is all about excess hp to weight ratio… get as light as possible, and add hp… 17) 200 rpm is 10% of my engine’s hp… make sure the gov is set up properly… also be sure the prop stops are set up properly. This is really important when the gov fails! (To flat, causes rpm over speed… controlling rpm with mp, the engine can be woefully underpowered. ) if I use (in the O…) 2500rpm instead of 2700rpm, my take off distance increases from 800’ to 1200’, when lightly loaded. A 50% increase. 18) Vy, like best glide, is weight dependent… 10kias faster when near MGTW, than very light…. PP thoughts only, not a mechanic, or CFI … stuff I picked up over the years… Best regards, -a- Edited March 8 by carusoam 3 1 Quote
Echo Posted March 9 Report Posted March 9 (edited) On 2/17/2024 at 7:26 PM, Echo said: I really look forward to having the edm installed as my cylinder temps in climb with a J cowl (with turbo baffles) on my E, as well as oil temps have been surprisingly low compared to my first E with lower cowl closure and forward oil cooler location. I am a 120mph cruise climber. I have NOT been opening cowl flaps in climb as temps have been under 350. Just loving the J cowl on my E… I guess I need to try climbing at 100mph and see what temps look like. Those are impressive climb rates up to 10k! Edited March 9 by Echo Quote
Ragsf15e Posted March 9 Report Posted March 9 8 minutes ago, Echo said: I guess I need to try climbing at 100mph and see what temps look like. Those are impressive climb rates up to 10k! It was fun to see and stayed cool because of the cold OAT. I think in the summer it might have been tougher to keep it cool. The most uncomfortable part was the deck angle made it harder to see outside. I like my 115ish cruise climb better. 1 Quote
802flyer Posted March 14 Report Posted March 14 I decided to get in on the fun yesterday, chasing more favorable winds. Takeoff weight around 2350lbs and temp on the ground around 30F.I was not as aggressive with the climb airspeed, starting off at my typical 120mph and slowing gradually to 100mph as I got to the end of climb.Started a timer entering the runway and it had just ticked over 15min as I cleared 12,000ft. So about 750fpm average (corrected for field elevation of 780).Next time, I’ll have to try the more aggressive deck angle at 100mph. Sent from my iPhone using Tapatalk Quote
Ragsf15e Posted March 14 Report Posted March 14 6 hours ago, 802flyer said: I decided to get in on the fun yesterday, chasing more favorable winds. Takeoff weight around 2350lbs and temp on the ground around 30F. I was not as aggressive with the climb airspeed, starting off at my typical 120mph and slowing gradually to 100mph as I got to the end of climb. Started a timer entering the runway and it had just ticked over 15min as I cleared 12,000ft. So about 750fpm average (corrected for field elevation of 780). Next time, I’ll have to try the more aggressive deck angle at 100mph. Sent from my iPhone using Tapatalk I was very surprised how much the slower Vy increased the average climb rate. On my F the poh shows 110mph Vy at mgw, slowing to 100mph at 10,000’. I believe the lower weight (less than mgw) also decreases Vy, so the 100pmh i used the second time around was probably closer to the real Vy and sure enough, I slightly beat book. 1 Quote
PT20J Posted March 15 Report Posted March 15 4 hours ago, Ragsf15e said: I was very surprised how much the slower Vy increased the average climb rate. On my F the poh shows 110mph Vy at mgw, slowing to 100mph at 10,000’. I believe the lower weight (less than mgw) also decreases Vy, so the 100pmh i used the second time around was probably closer to the real Vy and sure enough, I slightly beat book. Vy is the speed where there is the maximum difference between power available and power required. As the weight decreases, the amount of lift decreases and the required angle of attack also decreases which decreases induced drag. This has the effect of shifting the power required curve down and to the left slightly. However, the change is not great because the power available curve also has a slope and so the variation with weight is typically ignored -- maybe a 5 knots or less. 1 Quote
Shadrach Posted March 15 Report Posted March 15 15 hours ago, PT20J said: Vy is the speed where there is the maximum difference between power available and power required. As the weight decreases, the amount of lift decreases and the required angle of attack also decreases which decreases induced drag. This has the effect of shifting the power required curve down and to the left slightly. However, the change is not great because the power available curve also has a slope and so the variation with weight is typically ignored -- maybe a 5 knots or less. Interesting discussion. I must be misunderstanding how to calculate Vy using book numbers. This is how I learned to calculate Vy by weight: Book Vy at max gross of 2740lbs =99kts Take off weight me with 4hrs of fuel = 2135lbs 2135/2740=.78 √.78 = .88 .88*99kts = 87 Calculated Vy at 2135lbs = 87kts While 12kts is not a huge delta, it’s more significant than <5kts. Where is my error? Or is this the wrong formula for the calculation? Quote
N201MKTurbo Posted March 15 Report Posted March 15 I've been meaning to answer OP's question. I don't lean on climb, I sit up straight the whole way! TGIF 1 3 Quote
PT20J Posted March 15 Report Posted March 15 2 hours ago, Shadrach said: Interesting discussion. I must be misunderstanding how to calculate Vy using book numbers. This is how I learned to calculate Vy by weight: Book Vy at max gross of 2740lbs =99kts Take off weight me with 4hrs of fuel = 2135lbs 2135/2740=.78 √.78 = .88 .88*99kts = 87 Calculated Vy at 2141lbs = 87kts While 12kts is not a huge delta, it’s more significant than <5kts. Where is my error? Or is this the wrong formula for the calculation? Ross, that would be true if the power available were constant. However, it's not. Power available is thrust times TAS and so it is zero at zero airspeed and increases as airspeed increases until prop efficiency drops off. At low speeds, the variation in power available with airspeed is greatest and this affects Vy since ROC is the difference between power required (which varies as the square root of weight) and the power available. 1 Quote
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