Everything Radial Engines
#1601
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Hi guys
I'm fairly new to giant scale planes and have a PAU Su26m ,http://www.flypau.com/html/sukhoi/sukhoi.html. after2 months of trying to decide what typ of engine to go for ,
I am wanting to go for a radial engine for this plane , can any of you guys pleas be so kind and advise me which would be the best bet for this plane ,
I am also wanting to go for a 3 blade prop if it is all possible to try to keep it real looking ,
so what engine except the saito 3 cyl don't realy like that , they say the plane ok to 60cc but a little bit more wont hurt I think if it not to over powered .plus I will beff it up a bit in the critical places , this is a big plane for a 30%
so any input would be great I want to start to build the plane I have everything now for it ecept an engine
cheers lockit400
I'm fairly new to giant scale planes and have a PAU Su26m ,http://www.flypau.com/html/sukhoi/sukhoi.html. after2 months of trying to decide what typ of engine to go for ,
I am wanting to go for a radial engine for this plane , can any of you guys pleas be so kind and advise me which would be the best bet for this plane ,
I am also wanting to go for a 3 blade prop if it is all possible to try to keep it real looking ,
so what engine except the saito 3 cyl don't realy like that , they say the plane ok to 60cc but a little bit more wont hurt I think if it not to over powered .plus I will beff it up a bit in the critical places , this is a big plane for a 30%
so any input would be great I want to start to build the plane I have everything now for it ecept an engine
cheers lockit400
#1602
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ORIGINAL: the Gnome
Thunderchild, an engine, or one cylinder of it, needs three elementary things to work, correct fuel / air mixture, compression and ignition. As Your cylinder has compression and ignition, only an incorrect mixture can cause the problem, I think. While the engine is running, there must be coming fuel spray out of the exhaust of the dead cylinder, did You recognize that? Also a stupid question, but perhaps the exhaust is blocked by anything?
gnome
Holm und Rippenbruch
Thunderchild, an engine, or one cylinder of it, needs three elementary things to work, correct fuel / air mixture, compression and ignition. As Your cylinder has compression and ignition, only an incorrect mixture can cause the problem, I think. While the engine is running, there must be coming fuel spray out of the exhaust of the dead cylinder, did You recognize that? Also a stupid question, but perhaps the exhaust is blocked by anything?
gnome
Holm und Rippenbruch
#1604

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Imagine,
A reliable scale looking 7-cylinder radial engine with parts and support worldwide. It's something we have never had. This engine is going to be very popular. As soon as it's available I'm going to plunk down my cash!
#1605

Ok, Im going to jump in here and see if I can help.
Like Gnome said, we need:
Fire
Fuel (mix)
Compression
Easy enough to rule out fire, but many things can affect the fuel mixture and many things mechanical can affect the compression.
Lets try not to do any more of that! Lord knows we dont have enough as it is
Lets rule this one out....this is completely opposite of what a engine would do
I wonder about the compression. How did you check it? I would pull all plugs so there is no compression in all cylinders, spin with plug in one good cylinder for a baseline "feel" then pull that plug and put it in the bad cylinder to see if there was a noticeable difference. This should basically address the compression/mechanical issue. If you find something wrong then we will go from there. I am also suspecting that worst case, as you have been having exhaust problems, that you may have a burned valve or even warped. But this would probably show up while carefully checking the compression.
That being said, if it turns out feeling ok then I believe I would check on fuel mixture. I dont have a radial right now but I would suspect the seals in both ends of the intake tube. Thats something that would deteriorate over a long period of time to a point of letting in so much air that the fuel wouldnt burn. Or maybe let that cylinder run lean thereby creating a mechanical problem (back to compression). Simple step: poke around seals and check condition. Blow air in the fuel line and spray soapy water on the intake tube seal areas etc. Drastic step: pull engine and submerge in water for an air leak down test.
Im going to stop here and let this digest...and see what ya come up with. Traveling today, will ck in tonite (CST)
Like Gnome said, we need:
Fire
Fuel (mix)
Compression
Easy enough to rule out fire, but many things can affect the fuel mixture and many things mechanical can affect the compression.
as I am starting to run out of hair to pull out

They seem to move freely enough, but I am wondering if one might be sticking at operating temp and then freeing up when I have the hats off?
I wonder about the compression. How did you check it? I would pull all plugs so there is no compression in all cylinders, spin with plug in one good cylinder for a baseline "feel" then pull that plug and put it in the bad cylinder to see if there was a noticeable difference. This should basically address the compression/mechanical issue. If you find something wrong then we will go from there. I am also suspecting that worst case, as you have been having exhaust problems, that you may have a burned valve or even warped. But this would probably show up while carefully checking the compression.
That being said, if it turns out feeling ok then I believe I would check on fuel mixture. I dont have a radial right now but I would suspect the seals in both ends of the intake tube. Thats something that would deteriorate over a long period of time to a point of letting in so much air that the fuel wouldnt burn. Or maybe let that cylinder run lean thereby creating a mechanical problem (back to compression). Simple step: poke around seals and check condition. Blow air in the fuel line and spray soapy water on the intake tube seal areas etc. Drastic step: pull engine and submerge in water for an air leak down test.
Im going to stop here and let this digest...and see what ya come up with. Traveling today, will ck in tonite (CST)
#1606
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Thanks Dad Roman. Am working at the moment but when I get a moment, I shall do as you suggest.
And, no - no more hair pullin
And, no - no more hair pullin

#1607


Hi lockit !
The ASP 400 5 cylinder will probably fit this plane , the engine weighs 2.8 kg ,you also have the Saito 325 r5 , it is a bit lighter , 2.4 kg ,but not so powerful as the ASP.
I am working on anfw 190 86" for my ASP 400 .
The ASP 400 5 cylinder will probably fit this plane , the engine weighs 2.8 kg ,you also have the Saito 325 r5 , it is a bit lighter , 2.4 kg ,but not so powerful as the ASP.
I am working on anfw 190 86" for my ASP 400 .
#1608
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Hi nilsreinert123 ,
Thank you for the reply , I am very green behind the ears when it comes to Radials , But I have this SU and I really think that a radial is the only way to go ,
I have been trying to get as much info as possible but seem to come to dead ends , I'm in Japan but No one at my local field flys anything but Patern planes or small glow trainers ,
I Was wondering is there a gas radial around this size ? because the glow engines do make a mess , or can you advise me what other stuff I will need , as in exhaust ring glow driver and how do you guys set them up , I am a bit nervous obout getting a radial just becaus of knot knowing how to set it up with out actualy seeing one or knowing anyone that has one , But I would realy love to put one in the SU , I have the funds to buy , also I am going to hong kong in August so I was thinking I might beable to pick one up cheap If I can find a place there ,
Cheers Lockit400
Thank you for the reply , I am very green behind the ears when it comes to Radials , But I have this SU and I really think that a radial is the only way to go ,
I have been trying to get as much info as possible but seem to come to dead ends , I'm in Japan but No one at my local field flys anything but Patern planes or small glow trainers ,
I Was wondering is there a gas radial around this size ? because the glow engines do make a mess , or can you advise me what other stuff I will need , as in exhaust ring glow driver and how do you guys set them up , I am a bit nervous obout getting a radial just becaus of knot knowing how to set it up with out actualy seeing one or knowing anyone that has one , But I would realy love to put one in the SU , I have the funds to buy , also I am going to hong kong in August so I was thinking I might beable to pick one up cheap If I can find a place there ,
Cheers Lockit400
#1609


The ASP 400 is not difficult to operate , but it is important to have a good onboard glow system , with a good battery . I use an electronic glow driver from microsense.at , together with a 4000 lipo cell. you can also use nimh batteries for this glow driver. It works very well. Easy to set up.
It will be less messy if you buy a collector exhaust ring for it , and the sound gets better . I bought one from Keleo creations.
The smallest gas radial is a 150 cc , and that will be to big for your plane i think. The ASP is a good radial engine made to be used and flown.
How long air field to you have?
Good luck!
It will be less messy if you buy a collector exhaust ring for it , and the sound gets better . I bought one from Keleo creations.
The smallest gas radial is a 150 cc , and that will be to big for your plane i think. The ASP is a good radial engine made to be used and flown.
How long air field to you have?
Good luck!
#1610
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Hello,
I have been helping an older gentleman with a 1/3 scale balsa USA stearman which has a RCS 215 installed on it. I’ve been told that the plane was only flown once and the engine has about two hours on it. He purchased this set-up used.
My question is this; I have got everything set up what I believe to be proper, using Klotz oil mixed at 32:1. When advancing the throttle slowly the engine transitions smoothly up to about ½ power and I’m reading approximately 4400 rpm using a tach; the carburetor at this point is open approximately 1/2. When the throttle is further advanced the engine drops off in rpm dramatically as if there is an rpm limiting curve in the ignition module.
Do you have any advice regarding this condition?
Sincerely,
Ernie
I have been helping an older gentleman with a 1/3 scale balsa USA stearman which has a RCS 215 installed on it. I’ve been told that the plane was only flown once and the engine has about two hours on it. He purchased this set-up used.
My question is this; I have got everything set up what I believe to be proper, using Klotz oil mixed at 32:1. When advancing the throttle slowly the engine transitions smoothly up to about ½ power and I’m reading approximately 4400 rpm using a tach; the carburetor at this point is open approximately 1/2. When the throttle is further advanced the engine drops off in rpm dramatically as if there is an rpm limiting curve in the ignition module.
Do you have any advice regarding this condition?
Sincerely,
Ernie
#1611
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Hello Ernie,
I don't know, but it is possible that the ignition box has something like a rev limiter, but I think Your problem is the same as many older RCS215 have, the little pneumatic pump, that actuates the carburettor fuel pump, is too small to deliver enough fuel at high engine load, so the engine don't gets rich enough.
My new DeVries gas radial uses an EMOTEC electric fuel pump, that provides a constant 0,3bar fuel pressure, You can get it from Albinger Systemtechnik ( www.aps-pumpsystems.de ) or from PR Medien & Hobby ( www.Flugschau.de ), it works very good.
gnome
Holm und Rippenbruch
I don't know, but it is possible that the ignition box has something like a rev limiter, but I think Your problem is the same as many older RCS215 have, the little pneumatic pump, that actuates the carburettor fuel pump, is too small to deliver enough fuel at high engine load, so the engine don't gets rich enough.
My new DeVries gas radial uses an EMOTEC electric fuel pump, that provides a constant 0,3bar fuel pressure, You can get it from Albinger Systemtechnik ( www.aps-pumpsystems.de ) or from PR Medien & Hobby ( www.Flugschau.de ), it works very good.
gnome
Holm und Rippenbruch
#1612
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Hello Gnome,
Thanks for the quick reply. When I went over and picked up the engine and plane I found the small clear tube (pulse sensor?), disconnected at the carburetor, which led me to think the diaphram has gotten hard. However, just as soon as the motor hits 4400 rpm it shuts down as if it were an electrial issue.
I will look into the Emotec pump. Thanks.
Ernie
Thanks for the quick reply. When I went over and picked up the engine and plane I found the small clear tube (pulse sensor?), disconnected at the carburetor, which led me to think the diaphram has gotten hard. However, just as soon as the motor hits 4400 rpm it shuts down as if it were an electrial issue.
I will look into the Emotec pump. Thanks.
Ernie
#1613
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Ok guys I have decided to buy the asp 400 , So what I would like to know is , do any of you know of any R/C shops in Hong Kong that stock these engines I am going to HK In August for a quick 5 day trip , so I thought I might beable to save some dollaers buying in HK , Hi model has them for $895 or close to it , but I figured it would be cheaper In Hk ,
any heads up on where in HK would be great
lockie
any heads up on where in HK would be great
lockie
#1614

ORIGINAL: Skyern
engine transitions smoothly up to about ½ power and I’m reading approximately 4400 rpm using a tach; the carburetor at this point is open approximately 1/2. When the throttle is further advanced the engine drops off in rpm dramatically as if there is an rpm limiting curve in the ignition module.
engine transitions smoothly up to about ½ power and I’m reading approximately 4400 rpm using a tach; the carburetor at this point is open approximately 1/2. When the throttle is further advanced the engine drops off in rpm dramatically as if there is an rpm limiting curve in the ignition module.
Like to bring to your attention that the rated full power RPM is 5000 to 5200 so you actually are achieving almost full power (88%) at close to half throttle.
I dont have one so I cant give ya any advise (but Gnome can

Check your RPM spec here.. http://www.rcshowcase.com/html/RCS/rcs215.html
#1615
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Hello Dad,
You are right I should have mentioned what I had for set-up. I'm using 100 octane fuel mixed 32:1 (Klotz synthetic), turning a 3W 32-12 prop. Before attempting to start I adjusted all of the valve's to the recommended .007 gap. All of the plugs have been pulled, cleaned, and re-gapped to .014.
While you are right that the engine is rated at 5200 rpm (by the way the documentation I received says for only 5 second burst!), I am able to acheive this 4400 rpm at approximatly 1/2 throttle. This is not only on the throttle stick, but also by observeing the butterfly on the carb. I do believe I would be able to fly this plane at 4400 rpm; however if there is some sort of rev limiting function in the control module I think I would have to do some very creative programming at the transmitter as the engine just drops off even at one click of throttle above the 4400 rpm position. I should also mention that other than this situation the engine sounds great and funtions perfectly.
This could also create a situation whereby if it is rev limited, and I hold it to the 4400 level; what would happen if I requested a high demand on the prop; ie take-off, or large loop, any attitude where the engine might be pulled down?
I guess that I'm very leary of the current parameters of this set-up, and since I can get no answers from RCS or TBM I was hopeing for some inside information from this group.
Thank you all for your time and effort.
Ernie
You are right I should have mentioned what I had for set-up. I'm using 100 octane fuel mixed 32:1 (Klotz synthetic), turning a 3W 32-12 prop. Before attempting to start I adjusted all of the valve's to the recommended .007 gap. All of the plugs have been pulled, cleaned, and re-gapped to .014.
While you are right that the engine is rated at 5200 rpm (by the way the documentation I received says for only 5 second burst!), I am able to acheive this 4400 rpm at approximatly 1/2 throttle. This is not only on the throttle stick, but also by observeing the butterfly on the carb. I do believe I would be able to fly this plane at 4400 rpm; however if there is some sort of rev limiting function in the control module I think I would have to do some very creative programming at the transmitter as the engine just drops off even at one click of throttle above the 4400 rpm position. I should also mention that other than this situation the engine sounds great and funtions perfectly.
This could also create a situation whereby if it is rev limited, and I hold it to the 4400 level; what would happen if I requested a high demand on the prop; ie take-off, or large loop, any attitude where the engine might be pulled down?
I guess that I'm very leary of the current parameters of this set-up, and since I can get no answers from RCS or TBM I was hopeing for some inside information from this group.
Thank you all for your time and effort.
Ernie
#1617

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skyern,
I work on tons of motors with walboro pump type carb as this engine has on it. I find in most of them there is not much rpm change from half to full especialy if your running loaded on the ground. I wonder what you will see for RPM's in the air? I bet you will see more like 5k. just my 2 cents.
andy
I work on tons of motors with walboro pump type carb as this engine has on it. I find in most of them there is not much rpm change from half to full especialy if your running loaded on the ground. I wonder what you will see for RPM's in the air? I bet you will see more like 5k. just my 2 cents.
andy
#1618


Zoobear;
The Saito 325 has two plugs on each cylinder , which helps to keep all the cylinders running during idle. I guess thats the purpose of dual plugs !? The 325 is also lighter than the OS sirius 300 . I have no experience with any of them though. But i think i would have taken the Saito !
The Saito 325 has two plugs on each cylinder , which helps to keep all the cylinders running during idle. I guess thats the purpose of dual plugs !? The 325 is also lighter than the OS sirius 300 . I have no experience with any of them though. But i think i would have taken the Saito !
#1619
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Hi Andywakem,
Yes I agree with you and I will probably go with what is happening now, as I went over to a friends house yesterday who has one in a box just to see if there was some sort of "RPM adjustment screw or knob" on the control module and there is not; at least not on his engine.
My plan at the current time is to remove the engine, then remove and dis-assemble for inspection the carburator paying close attention in the pump section. I think I may have a weak diaphram or at least a hard spot on the rubber. If this all looks good, I will most likely ask Gnome to help me translate the web-sites he referred me to; in terms of an extra fuel pump in the delivery system, as I'm sure his English is much better than my German!
Again, thanks,
Skyern
Yes I agree with you and I will probably go with what is happening now, as I went over to a friends house yesterday who has one in a box just to see if there was some sort of "RPM adjustment screw or knob" on the control module and there is not; at least not on his engine.
My plan at the current time is to remove the engine, then remove and dis-assemble for inspection the carburator paying close attention in the pump section. I think I may have a weak diaphram or at least a hard spot on the rubber. If this all looks good, I will most likely ask Gnome to help me translate the web-sites he referred me to; in terms of an extra fuel pump in the delivery system, as I'm sure his English is much better than my German!
Again, thanks,
Skyern
#1621
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Hello All,
Just thought that I would follow up with what I discovered concerning the RCS 215 I've been working on. After re-building the carburator everything seems to be in proper working order and I intend to fly with it early next week.
Again thank you all for your input with this.
Skyern
Just thought that I would follow up with what I discovered concerning the RCS 215 I've been working on. After re-building the carburator everything seems to be in proper working order and I intend to fly with it early next week.
Again thank you all for your input with this.
Skyern
#1623
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ORIGINAL: Dad_Roman
Ok, Im going to jump in here and see if I can help.
Like Gnome said, we need:
Fire
Fuel (mix)
Compression
Easy enough to rule out fire, but many things can affect the fuel mixture and many things mechanical can affect the compression.
Lets try not to do any more of that! Lord knows we dont have enough as it is[img][/img]
Lets rule this one out....this is completely opposite of what a engine would do
I wonder about the compression. How did you check it? I would pull all plugs so there is no compression in all cylinders, spin with plug in one good cylinder for a baseline ''feel'' then pull that plug and put it in the bad cylinder to see if there was a noticeable difference. This should basically address the compression/mechanical issue. If you find something wrong then we will go from there. I am also suspecting that worst case, as you have been having exhaust problems, that you may have a burned valve or even warped. But this would probably show up while carefully checking the compression.
That being said, if it turns out feeling ok then I believe I would check on fuel mixture. I dont have a radial right now but I would suspect the seals in both ends of the intake tube. Thats something that would deteriorate over a long period of time to a point of letting in so much air that the fuel wouldnt burn. Or maybe let that cylinder run lean thereby creating a mechanical problem (back to compression). Simple step: poke around seals and check condition. Blow air in the fuel line and spray soapy water on the intake tube seal areas etc. Drastic step: pull engine and submerge in water for an air leak down test.
Im going to stop here and let this digest...and see what ya come up with. Traveling today, will ck in tonite (CST)
Ok, Im going to jump in here and see if I can help.
Like Gnome said, we need:
Fire
Fuel (mix)
Compression
Easy enough to rule out fire, but many things can affect the fuel mixture and many things mechanical can affect the compression.
as I am starting to run out of hair to pull out
They seem to move freely enough, but I am wondering if one might be sticking at operating temp and then freeing up when I have the hats off?
I wonder about the compression. How did you check it? I would pull all plugs so there is no compression in all cylinders, spin with plug in one good cylinder for a baseline ''feel'' then pull that plug and put it in the bad cylinder to see if there was a noticeable difference. This should basically address the compression/mechanical issue. If you find something wrong then we will go from there. I am also suspecting that worst case, as you have been having exhaust problems, that you may have a burned valve or even warped. But this would probably show up while carefully checking the compression.
That being said, if it turns out feeling ok then I believe I would check on fuel mixture. I dont have a radial right now but I would suspect the seals in both ends of the intake tube. Thats something that would deteriorate over a long period of time to a point of letting in so much air that the fuel wouldnt burn. Or maybe let that cylinder run lean thereby creating a mechanical problem (back to compression). Simple step: poke around seals and check condition. Blow air in the fuel line and spray soapy water on the intake tube seal areas etc. Drastic step: pull engine and submerge in water for an air leak down test.
Im going to stop here and let this digest...and see what ya come up with. Traveling today, will ck in tonite (CST)
I have been tied up with work unfortunately and only now just got around to replying ot your suggestions. I checked the compressions again and the cold cylinder seems in fact to have the best compression. I am now thinking I have a fuel issue. I am going to change nitro contents and try a fw different batches to see if it is my fuel that is the issue.
Will keep you in the loop. I really NEED to get my girl back in the air! I miis that wonderfull sound.
Cheers
TC
#1625
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Thnaks Dad-Roman!
That's what I like about this obsession (well it is a sport and hobby too I guess) is the friends in far flung places offering support and encouragement when you're running low on both.
Much obliged D_R [8D]
Calm winds and blue skies to ya'll
TC
That's what I like about this obsession (well it is a sport and hobby too I guess) is the friends in far flung places offering support and encouragement when you're running low on both.
Much obliged D_R [8D]
Calm winds and blue skies to ya'll

TC