New Hangar 9 P-51 60cc
05-17-2016, 09:58 AM
#1276
And there are other things that can be done after you get good results with exhaust heat control, and baffling to get reliable engine runs that fall into the category of performance/speed secrets that make the guys with the big engines wonder what you are doing to get what they see.
05-23-2016, 06:31 PM
#1278
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Ouch, that sucks!
That was a lot of power/RPM for a 22" blade in the16D series to handle. Seems like it held in there for some time.
The 25F series, or even the 32I looks like it might be a better fit at these levels. I've been thinking of trying the 25F 25.6" HS blades, which is pretty close to scale size. Nothing better than a big scale prop on a fast Mustang....but that's going to take a good amount of power to do it right
Have to say, both your Corsair and the Mustang look really impressive in the videos. Sucks you threw a blade
That was a lot of power/RPM for a 22" blade in the16D series to handle. Seems like it held in there for some time.
The 25F series, or even the 32I looks like it might be a better fit at these levels. I've been thinking of trying the 25F 25.6" HS blades, which is pretty close to scale size. Nothing better than a big scale prop on a fast Mustang....but that's going to take a good amount of power to do it right
Have to say, both your Corsair and the Mustang look really impressive in the videos. Sucks you threw a blade
05-24-2016, 01:45 PM
#1280
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Just finished my build of the H9 60cc P51. Reviewed the thread here prior to the build, and appreciate all the input and suggestions. Powered this with an EME-60 w/electric start. Modified the electric start to move the starter to the opposite side. Just fits. Picked up a generic Pitts muffler from Mile High as well. Quiet muffler. Doesn't fit in the cowl, but looks fine on the finished model.
The balance was spot-on, dead center in the recommended range (6.75" from leading edge). Apparently, the added weight of the autostart system was just enough to balance out the plane. I didn't need to add any additional weight at all. And yeah, I know I placed the port side star upside down, just a dumb mistake on my part.
I added a servo-operated choke, and optical kill switch in addition to the electric start. Batteries are 2S flight (3750 mAh) and 3S starter/ignition (2700 mAh). Beautiful plane, easy build, not too much to add here on top of the prior suggestions. Here's a few pics to add to the collection. Thanks everyone, I appreciate all your prior input!
The balance was spot-on, dead center in the recommended range (6.75" from leading edge). Apparently, the added weight of the autostart system was just enough to balance out the plane. I didn't need to add any additional weight at all. And yeah, I know I placed the port side star upside down, just a dumb mistake on my part.
I added a servo-operated choke, and optical kill switch in addition to the electric start. Batteries are 2S flight (3750 mAh) and 3S starter/ignition (2700 mAh). Beautiful plane, easy build, not too much to add here on top of the prior suggestions. Here's a few pics to add to the collection. Thanks everyone, I appreciate all your prior input!
Last edited by diablo2112; 05-24-2016 at 01:50 PM.
05-27-2016, 05:47 PM
#1286
This is the final installation of a DA 60 in my # 2 H 9 P 51 D. I took care to make the baffles fit against the inside of the cowl tightly to stop any leakage of muffler heat to the engines lower crankcase. The carburetor is completely sealed from the front engine area, no air can get to the carb intake from the hot engine and muffler. The motor is installed offset to the right to get the exhaust manifold away from the cowl for better muffler cooling AND no need to cut a large UGLY hole to accommodate a straight up engine install. If you look close to the pictures with the cowl removed, at the back of the engine is a plywood spacer stack to set the spinner distance. If this is deleted and the engine bolted directly to the firewall this would get almost all of the cylinder head back inside the cowl for a better looking front end. A crank spacer behind the spinner would be needed for spinner clearance and the AEROTECH P 51 method of air ducting is needed for all engine and muffler cooling. This would be easier if the engine is a rear exhaust model, I don't think Desert Aircraft has a rear exhaust engine in the sizes needed for this plane.
I have flown my # 1 P 51 D for almost a year and around 50 flights using this baffle installation and the DA 50r in hot Florida weather, and had no engine overheat-vapor lock issues at all after the first 2 flights once I perfected the baffle installation. When i bought the new DA 60 engine I swapped it in place of the DA 50r (bolt in fit) and flew it for 4 flights to check it for tuning issues. It starts instantly every time but is tuned rich from the factory, I will leave the mixture alone until it starts to break in-then it will begin to go richer and will need to be leaned a little. Even running rich it still hauls the plane pretty good and has excellent vertical climb ability. I have now begun assembling plane # 2 so the DA 60 has been moved to the New H 9 Mustang and the DA 50 r is back in its original TF P 51 B.
I have flown my # 1 P 51 D for almost a year and around 50 flights using this baffle installation and the DA 50r in hot Florida weather, and had no engine overheat-vapor lock issues at all after the first 2 flights once I perfected the baffle installation. When i bought the new DA 60 engine I swapped it in place of the DA 50r (bolt in fit) and flew it for 4 flights to check it for tuning issues. It starts instantly every time but is tuned rich from the factory, I will leave the mixture alone until it starts to break in-then it will begin to go richer and will need to be leaned a little. Even running rich it still hauls the plane pretty good and has excellent vertical climb ability. I have now begun assembling plane # 2 so the DA 60 has been moved to the New H 9 Mustang and the DA 50 r is back in its original TF P 51 B.
05-28-2016, 08:53 AM
#1288
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Len Todd,
I rotated the motor (not as much as the DA 50r) so that the exhaust manifold would not only be further away from the fiberglass cowl (it melts fiberglass) but would also get more of the air coming in through the chin scoop. Since the exhaust system is the hottest component inside of the cowl it needs the most attention for cooling. You absolutely have to prevent any hot air from the hot muffler from getting to the lower engine block and carburetor or it will vapor lock, and dead stick landings are next. I use a full baffle all the way around the motor, even under the muffler. I use weather strip from the hardware store to seal the baffle's edges. I initially flew plane number 1 with an onboard temp. sensor with a wifi receiver to get in flight temp. readings. After I found it never got over 90 degrees at the carbureter(on a 90 degree day) in flight, I removed the temp. sensor as no longer necessary.
When I first proposed this method the Internet trolls jumped all over me and ridiculed it as not workable. I continued to develop it anyway and it works fine and gives a cleaner engine cowling with fewer ugly holes and no AIR DAMS, which may be necessary for 3D planes which hover but I don't hover so I do it differently. When I fly at warbird events in gaggles my plane has a clear speed and climb advantage that has the guys with the big engines scratching their heads and trying to tune their carbs for more performance. They don't understand that light wing loading and streamlining is more effective (in aircraft) than cubic inches (works for cars). None of the more powerful full scale Mustangs were faster than the Allison version at low altitudes until North American went to work on the light weight version near the end of the war. They made it lighter, more stable and paid attention to improved airframe streamlining but the war was over so the Army never bought it.
I also prefer the B model mustang (I have both B and D Mustangs) over the D, it is noticeably faster than the D and is smoother flying in windy, gusty air especially at high speeds. I will convert one of the H 9 D models to a B this summer when it is too hot to fly unless I go out at dawn. I have just finished almost 2 years of testing electric motors in one of my TF GS B models and saw extremely good performance turning a 4 blade Varioprop from Germany. The 4 blade prop is actually more efficient than any 2 blade wood or plastic prop. It easily out ran and out climbed all of the other models no matter what motor they used. The TF GS Mustang doesn't have enough wing area or the right airfoil for the heavy flight batteries so i could only carry 1/2 of the needed batteries for duration.
I rotated the motor (not as much as the DA 50r) so that the exhaust manifold would not only be further away from the fiberglass cowl (it melts fiberglass) but would also get more of the air coming in through the chin scoop. Since the exhaust system is the hottest component inside of the cowl it needs the most attention for cooling. You absolutely have to prevent any hot air from the hot muffler from getting to the lower engine block and carburetor or it will vapor lock, and dead stick landings are next. I use a full baffle all the way around the motor, even under the muffler. I use weather strip from the hardware store to seal the baffle's edges. I initially flew plane number 1 with an onboard temp. sensor with a wifi receiver to get in flight temp. readings. After I found it never got over 90 degrees at the carbureter(on a 90 degree day) in flight, I removed the temp. sensor as no longer necessary.
When I first proposed this method the Internet trolls jumped all over me and ridiculed it as not workable. I continued to develop it anyway and it works fine and gives a cleaner engine cowling with fewer ugly holes and no AIR DAMS, which may be necessary for 3D planes which hover but I don't hover so I do it differently. When I fly at warbird events in gaggles my plane has a clear speed and climb advantage that has the guys with the big engines scratching their heads and trying to tune their carbs for more performance. They don't understand that light wing loading and streamlining is more effective (in aircraft) than cubic inches (works for cars). None of the more powerful full scale Mustangs were faster than the Allison version at low altitudes until North American went to work on the light weight version near the end of the war. They made it lighter, more stable and paid attention to improved airframe streamlining but the war was over so the Army never bought it.
I also prefer the B model mustang (I have both B and D Mustangs) over the D, it is noticeably faster than the D and is smoother flying in windy, gusty air especially at high speeds. I will convert one of the H 9 D models to a B this summer when it is too hot to fly unless I go out at dawn. I have just finished almost 2 years of testing electric motors in one of my TF GS B models and saw extremely good performance turning a 4 blade Varioprop from Germany. The 4 blade prop is actually more efficient than any 2 blade wood or plastic prop. It easily out ran and out climbed all of the other models no matter what motor they used. The TF GS Mustang doesn't have enough wing area or the right airfoil for the heavy flight batteries so i could only carry 1/2 of the needed batteries for duration.
sjhank, I like the way you think! Good information your posting!! I will adopt your cowl exit and baffle method. Interesting note on the 4 blade prop. This is only related to the electric motor and the Varioprop though correct? I have heard just the opposite regarding 4 blade props and gas engines
05-28-2016, 11:56 AM
#1289
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Ouch, that sucks!
That was a lot of power/RPM for a 22" blade in the16D series to handle. Seems like it held in there for some time.
The 25F series, or even the 32I looks like it might be a better fit at these levels. I've been thinking of trying the 25F 25.6" HS blades, which is pretty close to scale size. Nothing better than a big scale prop on a fast Mustang....but that's going to take a good amount of power to do it right
Have to say, both your Corsair and the Mustang look really impressive in the videos. Sucks you threw a blade
That was a lot of power/RPM for a 22" blade in the16D series to handle. Seems like it held in there for some time.
The 25F series, or even the 32I looks like it might be a better fit at these levels. I've been thinking of trying the 25F 25.6" HS blades, which is pretty close to scale size. Nothing better than a big scale prop on a fast Mustang....but that's going to take a good amount of power to do it right
Have to say, both your Corsair and the Mustang look really impressive in the videos. Sucks you threw a blade
I have a 25f prop that I'm going to be putting on my new corsair I was hoping to put it on the mustang to compare it to the 16d but we know how that turned out. Hoping it will be just as good if not better. The 25f is rated to 9000 rpm and is much strong
05-28-2016, 11:59 AM
#1291
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I flew mine with a gyro for about 100 flights. It doesn't need one but when you are putting hear up or down it gets a little mushy for my taste and with the gyro I had no mush at all. At about 140mph without the gyro it has a pretty good tail wag but no big deal
wooooahhhh!!!!!!!
05-28-2016, 07:19 PM
#1294
AC2,
You are correct about the props, I bought a Zinger 4 blade 22-14 and a set of 24-14 blades to try out. These blades are thick, intended for gas motors so it takes a lot of battery power to turn them. On the day I took both the Varioprop and the Zinger out to test them on the R 65cc electric motor I got good results flying the Varioprop,(I didn't have the best pitch angle set) then installed the Zinger. performance was good but the current draw was beyond too high for my setup. The Zinger is now a wall ornament waiting for a 100cc or larger gas motor. I continued to test pitch settings on the Varioprop and got progressively better performance until I set it at 19 inches pitch. At that point and with the 20 inches i tried later the takeoff acceleration was slow and i had to wait for the gear to retract before it would climb. Keeping the nose down and letting it wind up to about 95 mph it would then pull hard all the way up to top speed.
I backed the pitch down to 18 inches and this gave excellent acceleration from dead stopped to over 130 mph. Surprisingly, current draw was less than any 2 blade gas or electric prop that I tried and at any given speed or climb the 4 blade beat them all. Acceleration from a 90 mph level speed is awesome. Other warbird pilots would pull up alongside and go full throttle but my B model could easily accelerate away leaving them 50-150 feet behind after about a 1/4 mile run. They never tried it twice.
I have removed the electric motor power system from the B model and reinstalled the DA 50r that originally powered it. Turning a Graupner 22-12 Pro 2 blade it is no slouch and being about 7 lbs. lighter now it is more fun to fly and land. The electric stuff is going into a new TF P 47 Razorback i just got, being a lighter airframe and having a better airfoil than the TF P 51, I expect to be able to carry a higher capacity flight battery for more duration. I will buy the new, larger, Varioprop that has a higher rpm rating. I always had to limit the operating rpm of the 16D Varioprop, and i finally installed a set of 19.9 inch diameter SpitFire blades that can be revved much higher with out losing blades(catastrophic airframe disassembly).
The prop manufacturers have to make gas props more robust to be able to absorb the power pulse that the larger gas engines put out. Electrics have no power pulse but quick acceleration of a large prop produces incredible current spikes and corresponding voltage draw down that trips the current and low voltage cutoffs set in the ESC. I had to set current to 200 amps and disable the low voltage cutoff to avoid dead stick landings (and Mustangs don't glide). This did not cause ESC or battery problems. I only damaged 1, 4 cell pack in 2 years of testing.
Picture by BarracudaHockey.
You are correct about the props, I bought a Zinger 4 blade 22-14 and a set of 24-14 blades to try out. These blades are thick, intended for gas motors so it takes a lot of battery power to turn them. On the day I took both the Varioprop and the Zinger out to test them on the R 65cc electric motor I got good results flying the Varioprop,(I didn't have the best pitch angle set) then installed the Zinger. performance was good but the current draw was beyond too high for my setup. The Zinger is now a wall ornament waiting for a 100cc or larger gas motor. I continued to test pitch settings on the Varioprop and got progressively better performance until I set it at 19 inches pitch. At that point and with the 20 inches i tried later the takeoff acceleration was slow and i had to wait for the gear to retract before it would climb. Keeping the nose down and letting it wind up to about 95 mph it would then pull hard all the way up to top speed.
I backed the pitch down to 18 inches and this gave excellent acceleration from dead stopped to over 130 mph. Surprisingly, current draw was less than any 2 blade gas or electric prop that I tried and at any given speed or climb the 4 blade beat them all. Acceleration from a 90 mph level speed is awesome. Other warbird pilots would pull up alongside and go full throttle but my B model could easily accelerate away leaving them 50-150 feet behind after about a 1/4 mile run. They never tried it twice.
I have removed the electric motor power system from the B model and reinstalled the DA 50r that originally powered it. Turning a Graupner 22-12 Pro 2 blade it is no slouch and being about 7 lbs. lighter now it is more fun to fly and land. The electric stuff is going into a new TF P 47 Razorback i just got, being a lighter airframe and having a better airfoil than the TF P 51, I expect to be able to carry a higher capacity flight battery for more duration. I will buy the new, larger, Varioprop that has a higher rpm rating. I always had to limit the operating rpm of the 16D Varioprop, and i finally installed a set of 19.9 inch diameter SpitFire blades that can be revved much higher with out losing blades(catastrophic airframe disassembly).
The prop manufacturers have to make gas props more robust to be able to absorb the power pulse that the larger gas engines put out. Electrics have no power pulse but quick acceleration of a large prop produces incredible current spikes and corresponding voltage draw down that trips the current and low voltage cutoffs set in the ESC. I had to set current to 200 amps and disable the low voltage cutoff to avoid dead stick landings (and Mustangs don't glide). This did not cause ESC or battery problems. I only damaged 1, 4 cell pack in 2 years of testing.
Picture by BarracudaHockey.
05-28-2016, 07:41 PM
#1295
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The 16d and 25f are two props made by vairoprop in Germany. The 16d was what I had fail on my mustang but it's not rated for the rpm I was turning on my electric setup. The 25f is the newest in the line up and it is rated for 9000 rpm. I have a 25f but haven't flown it yet as my test platform didn't make it home after joe nall
05-29-2016, 09:13 AM
#1297
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Solution to Vapour Lock and Improving General Cooling
Hi sjhanc, LenTodd, diablo2112 and NICKELUP
Now its got warmer in the UK, I have started getting vapour lock problems with my installation and the restricted area around the engine and silencer. This is an EME60 autostart and it runs fine without the cowl. Have inserted a temperature sensor in front of the carb and with cowl on the incoming air was too hot at 60 deg C (122 F). So I cut out holes on either side of cowl (a bit like the real thing), enlarged the air intake under prop, opened and inserted grill in the under scoop AND very important cut a hole to the back of the pilot on dummy radio gear to get air up to the front. Otherwise the carb breathes from cowl. It works really well with the carb air temperature now running not much higher than ambient. Problem solved. Also going to revert back to a EME60 silencer which has flat block side and cut the cowl to accommodate, The custom silencer I had made (see my previous posts) occupies too much of the cowl volume under the frame mount behind the engine head. Not good.
Nice to see the work of NICKELUP in installing the autostart at 180 deg to clear.
05-29-2016, 11:29 AM
#1298
NICKLEUP,
I use APC 22-12 and Graupner 22-12 Props on both of my DA 50r and DA 60 engines for speed and climb. On my ZDZ 80 i use 24-14 for speed and climb but you really need to have a stout airframe for this engine. The DA engines are both reed valve intake designs which benefit from higher pitch props, this lugs the engine's rpm down down into the horsepower range. The ZDZ is a rear rotor valve intake design that is not rpm limited by reeds so propping it undersized in diameter allows it to rev high and the higher pitch gives it the speed that some pilots crave.
If your motor is a front crank valve or a piston port design it will also benefit from smaller diameter and higher pitch, just not as fast as the rear rotor designs. I have also seen engines with a side mounted carburetor that are reed valve designs, these need larger diameter props to lug the engine and higher pitch for speed and climb.
Listen to your prop when it is flying at its fastest,if you hear it barking or ripping you need more pitch for more speed or smaller diameter to reduce the ripping noise but it will fly slower. Be cautious looking for speed, if you get the plane up into its flutter speed it will instantly self-destruct.
I use streamlining techniques (flush head fasteners, gear doors, and no knobby stuff sticking out into the air stream). All of the holes that builders cut into the front end will reduce top speed so that is where you should start. Long exhaust pipes and cylinder heads and air dams for cooling all have a drag penalty to pay. The big hole cut in the side to accommodate oversize exhaust manifolds and the manifold itself disrupt air flow all the way back to the tail.
You have to commit to doing a lot of your own design in the cooling baffle area and trying to hide everything that wants to stick out of the airframe's skin to get good results, adding horsepower just makes it heavier and the extra weight causes the wing to fly at a higher angle-of-attack. The additional lift-over-drag penalty means that aircraft with over-sized engines usually don't fly much faster than the same plane with a well-streamlined smaller engine installation. This is a picture of my new H-9 P 51 D nose, this is the cleanest engine installation I have been able to build to date, but I have some ideas for the next plane.
I use APC 22-12 and Graupner 22-12 Props on both of my DA 50r and DA 60 engines for speed and climb. On my ZDZ 80 i use 24-14 for speed and climb but you really need to have a stout airframe for this engine. The DA engines are both reed valve intake designs which benefit from higher pitch props, this lugs the engine's rpm down down into the horsepower range. The ZDZ is a rear rotor valve intake design that is not rpm limited by reeds so propping it undersized in diameter allows it to rev high and the higher pitch gives it the speed that some pilots crave.
If your motor is a front crank valve or a piston port design it will also benefit from smaller diameter and higher pitch, just not as fast as the rear rotor designs. I have also seen engines with a side mounted carburetor that are reed valve designs, these need larger diameter props to lug the engine and higher pitch for speed and climb.
Listen to your prop when it is flying at its fastest,if you hear it barking or ripping you need more pitch for more speed or smaller diameter to reduce the ripping noise but it will fly slower. Be cautious looking for speed, if you get the plane up into its flutter speed it will instantly self-destruct.
I use streamlining techniques (flush head fasteners, gear doors, and no knobby stuff sticking out into the air stream). All of the holes that builders cut into the front end will reduce top speed so that is where you should start. Long exhaust pipes and cylinder heads and air dams for cooling all have a drag penalty to pay. The big hole cut in the side to accommodate oversize exhaust manifolds and the manifold itself disrupt air flow all the way back to the tail.
You have to commit to doing a lot of your own design in the cooling baffle area and trying to hide everything that wants to stick out of the airframe's skin to get good results, adding horsepower just makes it heavier and the extra weight causes the wing to fly at a higher angle-of-attack. The additional lift-over-drag penalty means that aircraft with over-sized engines usually don't fly much faster than the same plane with a well-streamlined smaller engine installation. This is a picture of my new H-9 P 51 D nose, this is the cleanest engine installation I have been able to build to date, but I have some ideas for the next plane.
05-30-2016, 08:41 AM
#1299
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I have been flying my EME 60 with a 24x10 Xoar warbird prop. The engine does handle it however its not at the higher RPM range, and I may switch to a 22x12 to compare. It flies fine with the 24x10 climbs great and maneuvers well but am sure more speed can be gained.
Last edited by ADKer; 05-30-2016 at 08:56 AM.
05-30-2016, 06:31 PM
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https://youtu.be/8xEfm11TeLk
Still working out the kinks and tuning but am loving the way this thing flies! Quick vid of my 4 flight.
Still working out the kinks and tuning but am loving the way this thing flies! Quick vid of my 4 flight.
Last edited by ADKer; 05-30-2016 at 06:36 PM.