How to start the RCV
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What is the best way to start the RCV engines? Some people have said to do it like a normal engine, on the spinner. Or is it best to do it behind the prop?
I am looking to put the RCV 90 on my TF P-51. Is there any one out there with this set up? What do you all think? any mounting, and muffler tips? any easy way to the fuel mixture?
Thanks
Brian
I am looking to put the RCV 90 on my TF P-51. Is there any one out there with this set up? What do you all think? any mounting, and muffler tips? any easy way to the fuel mixture?
Thanks
Brian
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Hello
This engine will start the convectional way. Any way you have been starting engines, this one will start the same way. I Hand flip all of mine with no problem.
Otto KUDRNA
This engine will start the convectional way. Any way you have been starting engines, this one will start the same way. I Hand flip all of mine with no problem.
Otto KUDRNA
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Brian:
I just bought an RCV 90 for my H-9 P-51. I am curently flying the plane with a YS 91 and the performance is quite good. My plan is to install the RCV and see what, if any, differences there are. I put about 1 hour and 20 minues on mine on the bench this past weekend. I plan to install the engine next week (after I get another hour on it). I will intially fly it with a two blade prop but I have pruchased a Zinger 17x10 three blade and a 16x10 four blade prop to try. I will keep you posted one the results.
Incidentally, I used a starter on my engine for the first hour of running. On the fifth 15 minute run and subsequent starts, I started the engine by hand. The thing it seems to like is to be chocked a lot. I covered the carb and flipped the prop over about 10-15 times. The engine started right up.
Later,
Ed
I just bought an RCV 90 for my H-9 P-51. I am curently flying the plane with a YS 91 and the performance is quite good. My plan is to install the RCV and see what, if any, differences there are. I put about 1 hour and 20 minues on mine on the bench this past weekend. I plan to install the engine next week (after I get another hour on it). I will intially fly it with a two blade prop but I have pruchased a Zinger 17x10 three blade and a 16x10 four blade prop to try. I will keep you posted one the results.
Incidentally, I used a starter on my engine for the first hour of running. On the fifth 15 minute run and subsequent starts, I started the engine by hand. The thing it seems to like is to be chocked a lot. I covered the carb and flipped the prop over about 10-15 times. The engine started right up.
Later,
Ed
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I read the starting procedure in the "Ask Otto" thread. I have additional engine starting questions...
If the engine is completely cowled in and thre is no access to the carburator to cover it with my finger to choke the engine before starting, what should we do?
Juice
If the engine is completely cowled in and thre is no access to the carburator to cover it with my finger to choke the engine before starting, what should we do?
Juice
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Thank You Ed
This is correct. Plugging the exhaust and turning the prop works beautifully, than point the tail of the airplane in the air and turn the prop over twice to allow all the fuel from the tail pipe to flow into the engine. Once the airplane is put back on the ground any excess will run out and the engine should start right up on the first or second flip. These engines are next to impossible to flood out. I have not yet been able to do so.
Otto Kudrna
This is correct. Plugging the exhaust and turning the prop works beautifully, than point the tail of the airplane in the air and turn the prop over twice to allow all the fuel from the tail pipe to flow into the engine. Once the airplane is put back on the ground any excess will run out and the engine should start right up on the first or second flip. These engines are next to impossible to flood out. I have not yet been able to do so.
Otto Kudrna
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Brian:
I haven't had a chance to do anything with the RCV other than run it a bit. I ordered a Zinger 16X10 four and three balded props today. My plan is to install the RCV in the H9 P51 and see how the engine performs. I will provide feed back and RPM data on these two props as well as the APC 16x12 that I broke the engine in on.
Later,
Ed
I haven't had a chance to do anything with the RCV other than run it a bit. I ordered a Zinger 16X10 four and three balded props today. My plan is to install the RCV in the H9 P51 and see how the engine performs. I will provide feed back and RPM data on these two props as well as the APC 16x12 that I broke the engine in on.
Later,
Ed
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Brian, et all:
Just an update on the RCV 90 and the H-9 Mustang. I finally decided to take the engine off of the test bench and am in the process of fitting it to the Mustang. This is no easy task as the RCV is about 1/2" shorter than the YS 91 that I had in the plane. I had to make a spacer plate to get the engine to the correct length to clear the cowl. What I did was to make two spacer plates of 1/4" ply each. I cut a good portion of the center of the rear plate out so that I could fit the RCV backing plate (couldn't fine any M4 x.7 screws long enough to go thru the 1/2" ply + the firewall + the thickness of the engine mounting flange. Anyway, once I got the rear spacer cut out I glued the two plates together to form a spacer of the correct thickness I began the process of mounting the spacer and engine to the Mustang firewall.
My hope is to get all of this done in the next few days. I have ZInger 16"x10" three and four bladed props on order and they should be here by Thursday. My hope is to get the plane in the air over this coming weekend. I have about 15 flights on the P-51 with YS 91 power so I should be able to tell fairly quickly if the engine is going to fly the model any better or worse than the YS.
By the way, I ran the RCv for about 30 minutes on Saturday (this makes a total of a hr and 50 minutes). Incidentally, all of my rining has been on Powermasted 10 % nitro with 18% oil. The I ran fifteen minutes at various throttle settings between 3800 and 4800 RPM. The last fifteen minutes we spent mostly above 5000 RPM. Using a Zinger 18"x6-10" prop, I tacked the engine at 5350 RPM. I spent some time leaning the engine out on the tip end and adjusting the carb bottom end. I did notice that with the above prop and the engine at full throttle (5300 RPM) the needle seems rather sensitive. I found that a movement of about 6-7 clicks take the engine from the slobbering rich side to the lean side (it falls off rapidly and drops RPM). This was rather surprising but I think it is managable. We shall see.
One other thing about the engine. Once I had about 1 hour on the engine, I could hand start it quite easily. I simply pulled the prop thru about 4 or 5 times and then attached the ingiter. One or two flips and it strated up.
I will keep the group posted on the progress of the experiment.
Later,
Ed
Just an update on the RCV 90 and the H-9 Mustang. I finally decided to take the engine off of the test bench and am in the process of fitting it to the Mustang. This is no easy task as the RCV is about 1/2" shorter than the YS 91 that I had in the plane. I had to make a spacer plate to get the engine to the correct length to clear the cowl. What I did was to make two spacer plates of 1/4" ply each. I cut a good portion of the center of the rear plate out so that I could fit the RCV backing plate (couldn't fine any M4 x.7 screws long enough to go thru the 1/2" ply + the firewall + the thickness of the engine mounting flange. Anyway, once I got the rear spacer cut out I glued the two plates together to form a spacer of the correct thickness I began the process of mounting the spacer and engine to the Mustang firewall.
My hope is to get all of this done in the next few days. I have ZInger 16"x10" three and four bladed props on order and they should be here by Thursday. My hope is to get the plane in the air over this coming weekend. I have about 15 flights on the P-51 with YS 91 power so I should be able to tell fairly quickly if the engine is going to fly the model any better or worse than the YS.
By the way, I ran the RCv for about 30 minutes on Saturday (this makes a total of a hr and 50 minutes). Incidentally, all of my rining has been on Powermasted 10 % nitro with 18% oil. The I ran fifteen minutes at various throttle settings between 3800 and 4800 RPM. The last fifteen minutes we spent mostly above 5000 RPM. Using a Zinger 18"x6-10" prop, I tacked the engine at 5350 RPM. I spent some time leaning the engine out on the tip end and adjusting the carb bottom end. I did notice that with the above prop and the engine at full throttle (5300 RPM) the needle seems rather sensitive. I found that a movement of about 6-7 clicks take the engine from the slobbering rich side to the lean side (it falls off rapidly and drops RPM). This was rather surprising but I think it is managable. We shall see.
One other thing about the engine. Once I had about 1 hour on the engine, I could hand start it quite easily. I simply pulled the prop thru about 4 or 5 times and then attached the ingiter. One or two flips and it strated up.
I will keep the group posted on the progress of the experiment.
Later,
Ed
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Ed,
I wanted to get into this topic in the prop section, but that would not have been very thread specific, would it?
I called Otto the other day and, among other things, asked him if the RCV's 'breathe' any easier than a normal 4-stroke. He said 'yes'. I'm sure you are familiar with the typical valve train of a 4-stroke. The RCV's pull easier and exhaust easier. This is prominent at operating speed. I'm thinking that is why we need to prime the tar out of them. It's not so prominent (the vaccum, pull) at low(hand) speeds as a typical 4- stroke. It needs more priming props turns to get the fuel in there. My theory on the sensitive needle valves is that the motor pulls SO well that it exaggerates any change to the needles. (as compared to typical 4) Any credence here?
Maybe I've been in engine exhaust too long.
Keep us posted on the 'Stang!!
Chip
I wanted to get into this topic in the prop section, but that would not have been very thread specific, would it?
I called Otto the other day and, among other things, asked him if the RCV's 'breathe' any easier than a normal 4-stroke. He said 'yes'. I'm sure you are familiar with the typical valve train of a 4-stroke. The RCV's pull easier and exhaust easier. This is prominent at operating speed. I'm thinking that is why we need to prime the tar out of them. It's not so prominent (the vaccum, pull) at low(hand) speeds as a typical 4- stroke. It needs more priming props turns to get the fuel in there. My theory on the sensitive needle valves is that the motor pulls SO well that it exaggerates any change to the needles. (as compared to typical 4) Any credence here?
Maybe I've been in engine exhaust too long.
Keep us posted on the 'Stang!!
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Chip
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All:
I just thought I would update you on my H-9 P-51 and the RCV 90. Unfortunatley I have not had a chance to do any flying with the combination. I received the Zinger 16 X 10 three and four blade props. The four blade is mounted on the engine and the engine on the model. I have everything hooked up and if the weather breaks on Sunday, I will go flying. I will try to get a picture in the next few days.
Ed
I just thought I would update you on my H-9 P-51 and the RCV 90. Unfortunatley I have not had a chance to do any flying with the combination. I received the Zinger 16 X 10 three and four blade props. The four blade is mounted on the engine and the engine on the model. I have everything hooked up and if the weather breaks on Sunday, I will go flying. I will try to get a picture in the next few days.
Ed
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Brian, et. all:
Well I braved the 48 degree temps and the 15-20 mph winds to get a flight in today on the H-9 P-51 and the RCV 90.
Before I get into the details let me offer a few thoughts. I, like many others, wanted to try to find an engine that could turn a three or four blade prop for some of my scale planes. I have been flying the H-9 P-51 with a YS 91 and a Graupner 14x7 three blade prop. With the combo, I was turning 9000 rpm on the ground and the model flew extremely well. Having flown a lot of different types of planes (BVM Aggressors (199 mph), 120" span A-10 (86 mph), Patriot with YS 45/pipe (144 mph), etc.) I beleive that I have a firly good feel for the approximate speed of a model. HAving said this, I would estimate that the speed of the P-51/YS combo was in the 105-110 mph range. I have about 20 flights on the YS 91 H-9 combo so I am fairly comfortable with the combo and I have a good feel for the speeds of the model in different wind conditions.
The RCv 90 that I flew today has just a tad under 2 hours of bench running time on it. The last 30 minutes of running time was with a Zinger 18" x 10" two blade prop. I tacked this combo at 5250 rpm on the test stand. I was using an OS F type plug, Powermaster 10% fuel with 18% oil. This fuel met the RCV requirements relative to castor/synthetic content and percentages. I installed the 4 blade Zinger 16"x10" prop on the RCV 90 and got it all cranked up and tacked. Boy the four blades sure looked neat on the front of the model! The engine turned this prop at 4900 rpm. I could lean the engine about another 100 rpm but it really fell off after that and I was reluctant to lean it too much on the ground. Static thrust felt pretty good. I could idle the engine down to about 1700 rpm. It was a little rough below this setting so I probably needed to adjust the bottom end a little but I left it as it was since it idled smoothly and transitioned pretty crisply to full throttle.
The take off was pretty smooth and took a little right aileron (could be wind or torque) immediately after breaking ground. Interestingly enough, I don't remember putting any right rudder into it for take off (like I had to do with the YS 91). Climb out was a little slower than the YS. I flew the plane for about 8-9 minutes and tried rolls, loops, dives and climbs. The plane seems to be noticably slower than the YS. The upwind passes were slower than with the YS. I would guess that the downwind passes were just a little slower that the YS combo upwind passes. I would estimate the model to be flying in the 65-70 mph range upwind and about 85 mph downwind. I don't think that I really expected the RCV to be as fast as the YS but I was hoping it would be close but it was not to be. With the YS 91 and the Graupner the model would do really large loops (maybe 200 ft in diameter) from level flight. With the RCV, the model would loop from level flight but they were fairly small loops (maybe 100 ft dia.). The other thing I noticed was that the model didn't have very much vertical (thought the bigger prop might give me more than the YS). One aspect that I fully expceted to happen on landing did. When you throttle the four blade prop back the model really bleeds speed in a hurry. It takes about 3-4 seconds for the speed to fall off, but when it does, it does so quickly.
Having said all of the above, let me say that I haven't given up on the RCV. I am going to try the 16x10 three blade prop this week ( I am going to a fly in and will et a chance to try it out). I beleive that what others have said in the various RCV threads is correct. That is that if you want to fly at a "scale like speed" then the RCV is probably a good choice. However, I am of the belief that if you want to go fas, you need to turn some RPM. Now that I have set the P-51 up so that I can easily change between engines at teh field, I will put somemore time on both combos and get back to all of you.
It was not and is not my intention to malign an engine or a manufacturer here, so please beleive me when I say that all of the above info was presented to help people make an informed decsision. If the RCV doesn't work out on the P-51, I will put it in my Top Flite Beechcraft Bonanza or their Stinson Reliant. I WILL find a good match for the engine. I am not going to abandon the unit. It is an exceptional work of art and it runs really well. I just need to find the right plane for it.
Hope this has been informative. Also, I am having trouble getting my photos of the combo sized correctly so that I can attach them. If someone wants to resize them for me let me know and I will e-mail them to you for posting.
Later,
Ed
Well I braved the 48 degree temps and the 15-20 mph winds to get a flight in today on the H-9 P-51 and the RCV 90.
Before I get into the details let me offer a few thoughts. I, like many others, wanted to try to find an engine that could turn a three or four blade prop for some of my scale planes. I have been flying the H-9 P-51 with a YS 91 and a Graupner 14x7 three blade prop. With the combo, I was turning 9000 rpm on the ground and the model flew extremely well. Having flown a lot of different types of planes (BVM Aggressors (199 mph), 120" span A-10 (86 mph), Patriot with YS 45/pipe (144 mph), etc.) I beleive that I have a firly good feel for the approximate speed of a model. HAving said this, I would estimate that the speed of the P-51/YS combo was in the 105-110 mph range. I have about 20 flights on the YS 91 H-9 combo so I am fairly comfortable with the combo and I have a good feel for the speeds of the model in different wind conditions.
The RCv 90 that I flew today has just a tad under 2 hours of bench running time on it. The last 30 minutes of running time was with a Zinger 18" x 10" two blade prop. I tacked this combo at 5250 rpm on the test stand. I was using an OS F type plug, Powermaster 10% fuel with 18% oil. This fuel met the RCV requirements relative to castor/synthetic content and percentages. I installed the 4 blade Zinger 16"x10" prop on the RCV 90 and got it all cranked up and tacked. Boy the four blades sure looked neat on the front of the model! The engine turned this prop at 4900 rpm. I could lean the engine about another 100 rpm but it really fell off after that and I was reluctant to lean it too much on the ground. Static thrust felt pretty good. I could idle the engine down to about 1700 rpm. It was a little rough below this setting so I probably needed to adjust the bottom end a little but I left it as it was since it idled smoothly and transitioned pretty crisply to full throttle.
The take off was pretty smooth and took a little right aileron (could be wind or torque) immediately after breaking ground. Interestingly enough, I don't remember putting any right rudder into it for take off (like I had to do with the YS 91). Climb out was a little slower than the YS. I flew the plane for about 8-9 minutes and tried rolls, loops, dives and climbs. The plane seems to be noticably slower than the YS. The upwind passes were slower than with the YS. I would guess that the downwind passes were just a little slower that the YS combo upwind passes. I would estimate the model to be flying in the 65-70 mph range upwind and about 85 mph downwind. I don't think that I really expected the RCV to be as fast as the YS but I was hoping it would be close but it was not to be. With the YS 91 and the Graupner the model would do really large loops (maybe 200 ft in diameter) from level flight. With the RCV, the model would loop from level flight but they were fairly small loops (maybe 100 ft dia.). The other thing I noticed was that the model didn't have very much vertical (thought the bigger prop might give me more than the YS). One aspect that I fully expceted to happen on landing did. When you throttle the four blade prop back the model really bleeds speed in a hurry. It takes about 3-4 seconds for the speed to fall off, but when it does, it does so quickly.
Having said all of the above, let me say that I haven't given up on the RCV. I am going to try the 16x10 three blade prop this week ( I am going to a fly in and will et a chance to try it out). I beleive that what others have said in the various RCV threads is correct. That is that if you want to fly at a "scale like speed" then the RCV is probably a good choice. However, I am of the belief that if you want to go fas, you need to turn some RPM. Now that I have set the P-51 up so that I can easily change between engines at teh field, I will put somemore time on both combos and get back to all of you.
It was not and is not my intention to malign an engine or a manufacturer here, so please beleive me when I say that all of the above info was presented to help people make an informed decsision. If the RCV doesn't work out on the P-51, I will put it in my Top Flite Beechcraft Bonanza or their Stinson Reliant. I WILL find a good match for the engine. I am not going to abandon the unit. It is an exceptional work of art and it runs really well. I just need to find the right plane for it.
Hope this has been informative. Also, I am having trouble getting my photos of the combo sized correctly so that I can attach them. If someone wants to resize them for me let me know and I will e-mail them to you for posting.
Later,
Ed
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Brian, et. all:
Well I braved the 48 degree temps and the 15-20 mph winds to get a flight in today on the H-9 P-51 and the RCV 90.
Before I get into the details let me offer a few thoughts. I, like many others, wanted to try to find an engine that could turn a three or four blade prop for some of my scale planes. I have been flying the H-9 P-51 with a YS 91 and a Graupner 14x7 three blade prop. With the combo, I was turning 9000 rpm on the ground and the model flew extremely well. Having flown a lot of different types of planes (BVM Aggressors (199 mph), 120" span A-10 (86 mph), Patriot with YS 45/pipe (144 mph), etc.) I beleive that I have a firly good feel for the approximate speed of a model. HAving said this, I would estimate that the speed of the P-51/YS combo was in the 105-110 mph range. I have about 20 flights on the YS 91 H-9 combo so I am fairly comfortable with the combo and I have a good feel for the speeds of the model in different wind conditions.
The RCv 90 that I flew today has just a tad under 2 hours of bench running time on it. The last 30 minutes of running time was with a Zinger 18" x 10" two blade prop. I tacked this combo at 5250 rpm on the test stand. I was using an OS F type plug, Powermaster 10% fuel with 18% oil. This fuel met the RCV requirements relative to castor/synthetic content and percentages. I installed the 4 blade Zinger 16"x10" prop on the RCV 90 and got it all cranked up and tacked. Boy the four blades sure looked neat on the front of the model! The engine turned this prop at 4900 rpm. I could lean the engine about another 100 rpm but it really fell off after that and I was reluctant to lean it too much on the ground. Static thrust felt pretty good. I could idle the engine down to about 1700 rpm. It was a little rough below this setting so I probably needed to adjust the bottom end a little but I left it as it was since it idled smoothly and transitioned pretty crisply to full throttle.
The take off was pretty smooth and took a little right aileron (could be wind or torque) immediately after breaking ground. Interestingly enough, I don't remember putting any right rudder into it for take off (like I had to do with the YS 91). Climb out was a little slower than the YS. I flew the plane for about 8-9 minutes and tried rolls, loops, dives and climbs. The plane seems to be noticably slower than the YS. The upwind passes were slower than with the YS. I would guess that the downwind passes were just a little slower that the YS combo upwind passes. I would estimate the model to be flying in the 65-70 mph range upwind and about 85 mph downwind. I don't think that I really expected the RCV to be as fast as the YS but I was hoping it would be close but it was not to be. With the YS 91 and the Graupner the model would do really large loops (maybe 200 ft in diameter) from level flight. With the RCV, the model would loop from level flight but they were fairly small loops (maybe 100 ft dia.). The other thing I noticed was that the model didn't have very much vertical (thought the bigger prop might give me more than the YS). One aspect that I fully expceted to happen on landing did. When you throttle the four blade prop back the model really bleeds speed in a hurry. It takes about 3-4 seconds for the speed to fall off, but when it does, it does so quickly.
Having said all of the above, let me say that I haven't given up on the RCV. I am going to try the 16x10 three blade prop this week ( I am going to a fly in and will et a chance to try it out). I beleive that what others have said in the various RCV threads is correct. That is that if you want to fly at a "scale like speed" then the RCV is probably a good choice. However, I am of the belief that if you want to go fas, you need to turn some RPM. Now that I have set the P-51 up so that I can easily change between engines at teh field, I will put somemore time on both combos and get back to all of you.
It was not and is not my intention to malign an engine or a manufacturer here, so please beleive me when I say that all of the above info was presented to help people make an informed decsision. If the RCV doesn't work out on the P-51, I will put it in my Top Flite Beechcraft Bonanza or their Stinson Reliant. I WILL find a good match for the engine. I am not going to abandon the unit. It is an exceptional work of art and it runs really well. I just need to find the right plane for it.
Hope this has been informative. Also, I am having trouble getting my photos of the combo sized correctly so that I can attach them. If someone wants to resize them for me let me know and I will e-mail them to you for posting.
Later,
Ed
Well I braved the 48 degree temps and the 15-20 mph winds to get a flight in today on the H-9 P-51 and the RCV 90.
Before I get into the details let me offer a few thoughts. I, like many others, wanted to try to find an engine that could turn a three or four blade prop for some of my scale planes. I have been flying the H-9 P-51 with a YS 91 and a Graupner 14x7 three blade prop. With the combo, I was turning 9000 rpm on the ground and the model flew extremely well. Having flown a lot of different types of planes (BVM Aggressors (199 mph), 120" span A-10 (86 mph), Patriot with YS 45/pipe (144 mph), etc.) I beleive that I have a firly good feel for the approximate speed of a model. HAving said this, I would estimate that the speed of the P-51/YS combo was in the 105-110 mph range. I have about 20 flights on the YS 91 H-9 combo so I am fairly comfortable with the combo and I have a good feel for the speeds of the model in different wind conditions.
The RCv 90 that I flew today has just a tad under 2 hours of bench running time on it. The last 30 minutes of running time was with a Zinger 18" x 10" two blade prop. I tacked this combo at 5250 rpm on the test stand. I was using an OS F type plug, Powermaster 10% fuel with 18% oil. This fuel met the RCV requirements relative to castor/synthetic content and percentages. I installed the 4 blade Zinger 16"x10" prop on the RCV 90 and got it all cranked up and tacked. Boy the four blades sure looked neat on the front of the model! The engine turned this prop at 4900 rpm. I could lean the engine about another 100 rpm but it really fell off after that and I was reluctant to lean it too much on the ground. Static thrust felt pretty good. I could idle the engine down to about 1700 rpm. It was a little rough below this setting so I probably needed to adjust the bottom end a little but I left it as it was since it idled smoothly and transitioned pretty crisply to full throttle.
The take off was pretty smooth and took a little right aileron (could be wind or torque) immediately after breaking ground. Interestingly enough, I don't remember putting any right rudder into it for take off (like I had to do with the YS 91). Climb out was a little slower than the YS. I flew the plane for about 8-9 minutes and tried rolls, loops, dives and climbs. The plane seems to be noticably slower than the YS. The upwind passes were slower than with the YS. I would guess that the downwind passes were just a little slower that the YS combo upwind passes. I would estimate the model to be flying in the 65-70 mph range upwind and about 85 mph downwind. I don't think that I really expected the RCV to be as fast as the YS but I was hoping it would be close but it was not to be. With the YS 91 and the Graupner the model would do really large loops (maybe 200 ft in diameter) from level flight. With the RCV, the model would loop from level flight but they were fairly small loops (maybe 100 ft dia.). The other thing I noticed was that the model didn't have very much vertical (thought the bigger prop might give me more than the YS). One aspect that I fully expceted to happen on landing did. When you throttle the four blade prop back the model really bleeds speed in a hurry. It takes about 3-4 seconds for the speed to fall off, but when it does, it does so quickly.
Having said all of the above, let me say that I haven't given up on the RCV. I am going to try the 16x10 three blade prop this week ( I am going to a fly in and will et a chance to try it out). I beleive that what others have said in the various RCV threads is correct. That is that if you want to fly at a "scale like speed" then the RCV is probably a good choice. However, I am of the belief that if you want to go fas, you need to turn some RPM. Now that I have set the P-51 up so that I can easily change between engines at teh field, I will put somemore time on both combos and get back to all of you.
It was not and is not my intention to malign an engine or a manufacturer here, so please beleive me when I say that all of the above info was presented to help people make an informed decsision. If the RCV doesn't work out on the P-51, I will put it in my Top Flite Beechcraft Bonanza or their Stinson Reliant. I WILL find a good match for the engine. I am not going to abandon the unit. It is an exceptional work of art and it runs really well. I just need to find the right plane for it.
Hope this has been informative. Also, I am having trouble getting my photos of the combo sized correctly so that I can attach them. If someone wants to resize them for me let me know and I will e-mail them to you for posting.
Later,
Ed
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First of all decrease your oil content in your fuel to 14-16% max. Than raise the Nitro content to 15%. Than as I recommend in all the posts, put on a Zinger 18x12 or 18x14 2 blade prop, and try your Mustang again. You changed too many variables from the norm. to make an appropriate comparison in flight. You fly your YS on 20/20 fuel because that is EXACTLY the fuel which YS recommends. If you run less oil than 20%, that would mean that you increase performance. RCV recommends 14-16% oil MAX not 18%, so you are exceeding the oil content hence hindering performance. Also you are running only half the Nitro of the YS. Raise that to 15%, which is the maximum recommended by RCV. Such as 20% is the maximum recommended by YS. Try this combination, than tell us what you think. You should find a considerable difference. The RCV is designed and intended to turn a large and wide prop very slowly. You are turning the YS at around 9000 revs with a 7" pitch prop and only 3 blades. If you had no slippage at all, your airplane could reach a maximum in-flight speed of 60 mph. You are turning the RCV at only 4900 revs with a 10" pitch prop and four blades, which gives you a maximum in-flight speed of 46 mph. this is simple math. Put a Zinger 15x14 three blade prop with rounded off and thinned out prop tips on it and see what you think. Plus You have decreased efficiency by about 10* by adding an extra blade to the combo. Next time when you make comparisons, change only one variable at a time. this being the Engine/fuel combination.
Otto Kudrna, RCV Tech Support
PS Take it from someone who has about 600 hours on these engines.
First of all decrease your oil content in your fuel to 14-16% max. Than raise the Nitro content to 15%. Than as I recommend in all the posts, put on a Zinger 18x12 or 18x14 2 blade prop, and try your Mustang again. You changed too many variables from the norm. to make an appropriate comparison in flight. You fly your YS on 20/20 fuel because that is EXACTLY the fuel which YS recommends. If you run less oil than 20%, that would mean that you increase performance. RCV recommends 14-16% oil MAX not 18%, so you are exceeding the oil content hence hindering performance. Also you are running only half the Nitro of the YS. Raise that to 15%, which is the maximum recommended by RCV. Such as 20% is the maximum recommended by YS. Try this combination, than tell us what you think. You should find a considerable difference. The RCV is designed and intended to turn a large and wide prop very slowly. You are turning the YS at around 9000 revs with a 7" pitch prop and only 3 blades. If you had no slippage at all, your airplane could reach a maximum in-flight speed of 60 mph. You are turning the RCV at only 4900 revs with a 10" pitch prop and four blades, which gives you a maximum in-flight speed of 46 mph. this is simple math. Put a Zinger 15x14 three blade prop with rounded off and thinned out prop tips on it and see what you think. Plus You have decreased efficiency by about 10* by adding an extra blade to the combo. Next time when you make comparisons, change only one variable at a time. this being the Engine/fuel combination.
Otto Kudrna, RCV Tech Support
PS Take it from someone who has about 600 hours on these engines.
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Otto:
After reading your response, I have the following comments.
1. The RCV instructions, the ones that come with the engine from the manufacturer states " We recommend 10% nitro.... nitro fuels with higher than 10% nitro appear to offer no performance benefits". "Fuels must have a MINIMUM content of 15%, no more than 6% castor". In the instructions they DO NOT state a maximum oil content. I have checked with Powermaster and they confirmed that the oil content is as recommended/acceptable by RCV.
2. Yes I could put an 18" prop on the mustang if I extended the gear by about 1.5". If I did this it would not fit in the wheel well. I prefer to fly scale or semi scale models that LOOK like the real thing. A Mustang with the spinner elevated to the height required by the 18" prop would not look scale. I think you are missing the point by recommending that I fit a two bladed prop. Besides, the intent of this experiment was to try the RCV on the mustang for a couple of reasons. First I wanted to try to find something that would allow me to swing a four bladed or a three balded prop and secondly, I wanted to find an engine that would fit within the cowl. For these reasons, I purchased the RCV.
3. I disagree with your comments that I have changed too many variables. I have run the appropriate nitro content( AS RECOMMENDED BY THE MANUFACUTRER) and I am running above the minimum oil content (with the acceptable level of castor) RECOMMENDED BY THE MANUFACTURER. So I believe that your comments about my deviations from the recommended are WAY OFF BASE.
4. I would agree that the engine was intended to turn a large prop at a slower RPM. When I purchased this engine, as I said above, I was trying to find an emgine that would allow me to turn a four bladed prop and fly a plane faster than 46 or 60 mph.
Having said all of this, I will present some additional observations made over the last two days of flying the combo. I currently have approximately 12 flights on the plane/engine combo and have flown it with four different props. I have put a total of approximately 3 hours running time on the engine.
On Thursday and Friday I put about eight flights on the H9 P-51 and the RCV 90 combo. During the course of these flights I let a few of the giant scale warbird pilots (I was at a Fly In in Edinbug TX) fly the model with difefrent props. They other pilots also concurred with my speed estimates. Incidentally, we had the opportunity to fly just after a Ziroli F-8 Bearcat with a BME 102cc engine (clocked at 139 mph during a previous event), so we were using the Bearcat as a rough gauge of the speed of the P-51 and compare how fast the P-51 covered the same length of runway as compared to the Bearcat.
1. Zinger 16" x 10" four bladed prop. 4500 RPM. Plane flew rather slow, approximately 60-65 mph. I thought the model flew too slowly, didn't have much vertical and struggled thru a loop.
2. Zinger 16"x10" four blade cut to 15"x10". 4750 RPM. Marginally better than the 16x10 but still not very impressive. Still same problem with loops. Speed is aproximately 65 mph
3. Zinger 16"x10" three blade. 5100 RPM. better flight characteristics than either of the four balde props. We are getting there. Speed approximately 75 mph
4. APC 16"x12" tow bladed prop. 5700 RPM. Much better than any of the other combos, but still not fast enough to replace the YS 91. Estimated speed is 80-85 MPH.
As you can see, the two bladed prop get the plane closer to where I wanted to be, but it just didn't fly as well as hoped for with the four blade props. As I said in my previous post, I don't think that this is the combo I want for a warbird. After having a number of fliers fly the plane and discuss the appropriate applications for the engine. I believe that the consensus is that this engine would do well in a scale plane like a Taylorcraft, Stinson or maybe a WWI bipe.
As I said in my previous post, it was my intention to try this combo and report back to the forum. I have no ax to grind with anyone (Otto, RCV or anyone else) but I wanted to present my findings so that modelers could make an informed decision. My thoughts are that (this may seem obvious but I wanted to try the combo) if you want to go fast with a warbird type of model, look at a two stroke or possibly a four stroke and a two blade prop.
Ed
After reading your response, I have the following comments.
1. The RCV instructions, the ones that come with the engine from the manufacturer states " We recommend 10% nitro.... nitro fuels with higher than 10% nitro appear to offer no performance benefits". "Fuels must have a MINIMUM content of 15%, no more than 6% castor". In the instructions they DO NOT state a maximum oil content. I have checked with Powermaster and they confirmed that the oil content is as recommended/acceptable by RCV.
2. Yes I could put an 18" prop on the mustang if I extended the gear by about 1.5". If I did this it would not fit in the wheel well. I prefer to fly scale or semi scale models that LOOK like the real thing. A Mustang with the spinner elevated to the height required by the 18" prop would not look scale. I think you are missing the point by recommending that I fit a two bladed prop. Besides, the intent of this experiment was to try the RCV on the mustang for a couple of reasons. First I wanted to try to find something that would allow me to swing a four bladed or a three balded prop and secondly, I wanted to find an engine that would fit within the cowl. For these reasons, I purchased the RCV.
3. I disagree with your comments that I have changed too many variables. I have run the appropriate nitro content( AS RECOMMENDED BY THE MANUFACUTRER) and I am running above the minimum oil content (with the acceptable level of castor) RECOMMENDED BY THE MANUFACTURER. So I believe that your comments about my deviations from the recommended are WAY OFF BASE.
4. I would agree that the engine was intended to turn a large prop at a slower RPM. When I purchased this engine, as I said above, I was trying to find an emgine that would allow me to turn a four bladed prop and fly a plane faster than 46 or 60 mph.
Having said all of this, I will present some additional observations made over the last two days of flying the combo. I currently have approximately 12 flights on the plane/engine combo and have flown it with four different props. I have put a total of approximately 3 hours running time on the engine.
On Thursday and Friday I put about eight flights on the H9 P-51 and the RCV 90 combo. During the course of these flights I let a few of the giant scale warbird pilots (I was at a Fly In in Edinbug TX) fly the model with difefrent props. They other pilots also concurred with my speed estimates. Incidentally, we had the opportunity to fly just after a Ziroli F-8 Bearcat with a BME 102cc engine (clocked at 139 mph during a previous event), so we were using the Bearcat as a rough gauge of the speed of the P-51 and compare how fast the P-51 covered the same length of runway as compared to the Bearcat.
1. Zinger 16" x 10" four bladed prop. 4500 RPM. Plane flew rather slow, approximately 60-65 mph. I thought the model flew too slowly, didn't have much vertical and struggled thru a loop.
2. Zinger 16"x10" four blade cut to 15"x10". 4750 RPM. Marginally better than the 16x10 but still not very impressive. Still same problem with loops. Speed is aproximately 65 mph
3. Zinger 16"x10" three blade. 5100 RPM. better flight characteristics than either of the four balde props. We are getting there. Speed approximately 75 mph
4. APC 16"x12" tow bladed prop. 5700 RPM. Much better than any of the other combos, but still not fast enough to replace the YS 91. Estimated speed is 80-85 MPH.
As you can see, the two bladed prop get the plane closer to where I wanted to be, but it just didn't fly as well as hoped for with the four blade props. As I said in my previous post, I don't think that this is the combo I want for a warbird. After having a number of fliers fly the plane and discuss the appropriate applications for the engine. I believe that the consensus is that this engine would do well in a scale plane like a Taylorcraft, Stinson or maybe a WWI bipe.
As I said in my previous post, it was my intention to try this combo and report back to the forum. I have no ax to grind with anyone (Otto, RCV or anyone else) but I wanted to present my findings so that modelers could make an informed decision. My thoughts are that (this may seem obvious but I wanted to try the combo) if you want to go fast with a warbird type of model, look at a two stroke or possibly a four stroke and a two blade prop.
Ed
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Ed
It is obvious that the RCV engine is not an engine for you.
For everyone reading this post, please read the RCV90/ 4Pi 80" Douglas Skyraider combo review in the up coming Flying Models Mag. This review is done bi Mr. Nick Zeroli Sr.
Thank You
Otto Kudrna Rcv Tech Support
It is obvious that the RCV engine is not an engine for you.
For everyone reading this post, please read the RCV90/ 4Pi 80" Douglas Skyraider combo review in the up coming Flying Models Mag. This review is done bi Mr. Nick Zeroli Sr.
Thank You
Otto Kudrna Rcv Tech Support
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Ed
Thank you for your information I am going to try and get my RCV here in the next couple of weeks. I am building a Top flight P-51 and i want to fly it very scale. This sounds like the combo i want.
I have one more question. how does the engine run?
thanks
Brian
Thank you for your information I am going to try and get my RCV here in the next couple of weeks. I am building a Top flight P-51 and i want to fly it very scale. This sounds like the combo i want.
I have one more question. how does the engine run?
thanks
Brian
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Brian:
The engine runs very well. I have found that the more time you have on it the easier it is to start. I used a starter (up against the spinner) for the first five or six 15 minute runs. After about 1 1/2 half hours the engine started by hand very easily. I currently have three hours on the engine and if you choke it and get it really wet, like you would a larger OS, it starts on the first or second flip. I really like the engine and I will find an appropriate plane for the engine.
One thing yo really nedd to do is to ensure that yo have adequate cooling. I ran mine without the cowl for all of my test flights and it ran failry cool but it does seem to run a lillte hotter than my YS. Otto thinks I need to change my fuel and I might try a different combo of fuel/prop at a later date but I just got one of the new World Models P-51 into which I wil install a Quadra 42.
One other thing. After reading Nick Zirolis review of an RCV in the latest edition of Flying Models, he seems to like the combo in his 80" Skyraider using a two bladed prop. I will have to admit that the four blade prop on the P-51 was one of the neatest things around. All of the guys at the field really liked the way it looked. I don't know if it was just me getting more experience with the model or the prop but when I flew the plane with the four blade prop the landings were just great. About 3-4 seconds after I pulled the power off, the model really slowed down . As the model slowed down and bled off speed, I just pulled some up leavotor and it just settled in on three points very nicely. My best landings with the model were with the RCV and the four blade prop.
Hope you enjoy your combo and I would welcome your coments/observations on the TF P-51 and RCV. Good luck. I have some photos of the H9 P-51 and the RCV but I have been unable to get them resized to a small enough size to be able to post. If you like, I can send you the photos and you can post them if you want to. I think that there are some readers that would like to see the pictures but I can't figure out how to get them to an acceptable number of bytes for RCU to accept.
Later,
Ed
The engine runs very well. I have found that the more time you have on it the easier it is to start. I used a starter (up against the spinner) for the first five or six 15 minute runs. After about 1 1/2 half hours the engine started by hand very easily. I currently have three hours on the engine and if you choke it and get it really wet, like you would a larger OS, it starts on the first or second flip. I really like the engine and I will find an appropriate plane for the engine.
One thing yo really nedd to do is to ensure that yo have adequate cooling. I ran mine without the cowl for all of my test flights and it ran failry cool but it does seem to run a lillte hotter than my YS. Otto thinks I need to change my fuel and I might try a different combo of fuel/prop at a later date but I just got one of the new World Models P-51 into which I wil install a Quadra 42.
One other thing. After reading Nick Zirolis review of an RCV in the latest edition of Flying Models, he seems to like the combo in his 80" Skyraider using a two bladed prop. I will have to admit that the four blade prop on the P-51 was one of the neatest things around. All of the guys at the field really liked the way it looked. I don't know if it was just me getting more experience with the model or the prop but when I flew the plane with the four blade prop the landings were just great. About 3-4 seconds after I pulled the power off, the model really slowed down . As the model slowed down and bled off speed, I just pulled some up leavotor and it just settled in on three points very nicely. My best landings with the model were with the RCV and the four blade prop.
Hope you enjoy your combo and I would welcome your coments/observations on the TF P-51 and RCV. Good luck. I have some photos of the H9 P-51 and the RCV but I have been unable to get them resized to a small enough size to be able to post. If you like, I can send you the photos and you can post them if you want to. I think that there are some readers that would like to see the pictures but I can't figure out how to get them to an acceptable number of bytes for RCU to accept.
Later,
Ed