Everything Radial Engines
#3904
Junior Member

Hey y’all. Figured this might be a good spot to ask about an engine I am inheriting. It’s an O.S. FR7 420 Sirius. The gentleman who owned it only ground ran it twice. It has never flown. I don’t believe the engine will turn freely right now. I will go pick it up in May and find out. Any advice on how to proceed with it? I would like to fly it but cannot find a suitable kit or plan from my modest collection. Any recommendations? I would like to perhaps find plans for an Air Tractor 401, or Stinson, or Howard, or whatever, of the right size. It is about 10” diameter. Help?
Chumpy77
Chumpy77
#3905

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Hey y’all. Figured this might be a good spot to ask about an engine I am inheriting. It’s an O.S. FR7 420 Sirius. The gentleman who owned it only ground ran it twice. It has never flown. I don’t believe the engine will turn freely right now. I will go pick it up in May and find out. Any advice on how to proceed with it? I would like to fly it but cannot find a suitable kit or plan from my modest collection. Any recommendations? I would like to perhaps find plans for an Air Tractor 401, or Stinson, or Howard, or whatever, of the right size. It is about 10” diameter. Help?
Chumpy77
Chumpy77
Flies it very scale and fits the cowl like a glove.
You should be VERY careful about buying a used glow radial. IF the previous owner did not run it totally out of fuel then squirt lots of After-run oil and thoroughly work that through the engine, there could be RUST inside the engine.
#3906
Senior Member

Hello all saito fa-325r5 now have the main needle from Saito fa-100.
I helped a friend with the same problem and they got better.
now I don't know how old your engine is!!!
I helped a friend with the same problem and they got better.
now I don't know how old your engine is!!!
#3907
Junior Member

Wow! Well I’m not purchasing it, literally inheriting it from my best friend’s father’s passing. I taught the man to fly R/C back in late 70’s. I am intending to open it up to inspect for corrosion. Thank you for the response.
Chumpy77
Chumpy77
#3908

Hello all. I need to r&r bearings on my 450 R-3 Saito. Does anyone have experience with valve timing upon reassembly? I have done lots of Saito singles but never any of the triples. Please and thank you.
Aaron-
Aaron-
#3909

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!f It is an inline engine, all you need to do is the number one cylinder, time it and the cam and crankshaft is ground for the firing order. It is like doing a single cylinder. Does not matter if it inline, v or radial. Find number one and time it. The engine will do the rest... Joe
#3910

!f It is an inline engine, all you need to do is the number one cylinder, time it and the cam and crankshaft is ground for the firing order. It is like doing a single cylinder. Does not matter if it inline, v or radial. Find number one and time it. The engine will do the rest... Joe
#3911

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Well, I think you are right, but I will go over the tune up again. if you have timing marks to line up , time the cam crankshaft aligning marks. The cam and crankshaft are ground to time correctly then. To set the valve lash, turn the engine over and bring up no 1 cylinder again on the power stroke with both valves closed and set the valve lash or clearance to specs at this point. Then turn the engine over to next cylinder in firing order, top dead center on power stroke again and set the valve lash again. Do the same for the other cylinders untill each cylinder, TDC in FIRING order if you know it. If you dont know the fireing order, you can figure it out. Barring that, do it all by turning each cylinder top dead center, on compression, power stroke, valves closed and set that cylinder. In other words, rather do it in firing order, set no1, set 2, set 3 and so on on power stroke, compression TDC. You are done.
#3912

Well, I think you are right, but I will go over the tune up again. if you have timing marks to line up , time the cam crankshaft aligning marks. The cam and crankshaft are ground to time correctly then. To set the valve lash, turn the engine over and bring up no 1 cylinder again on the power stroke with both valves closed and set the valve lash or clearance to specs at this point. Then turn the engine over to next cylinder in firing order, top dead center on power stroke again and set the valve lash again. Do the same for the other cylinders untill each cylinder, TDC in FIRING order if you know it. If you dont know the fireing order, you can figure it out. Barring that, do it all by turning each cylinder top dead center, on compression, power stroke, valves closed and set that cylinder. In other words, rather do it in firing order, set no1, set 2, set 3 and so on on power stroke, compression TDC. You are done.
Aaron-
#3913


They time like doing three singles. Firing order is every other cylinder in turn. Start with #1 @ TDC, drop cam and carrier assembly in place just as with a single. Turn crank past #2 to #3, set that cam. Now turn to #2 and set that cam up.
Done
Actually doesn't matter where you start. Just follow the skip a cylinder pattern from wherever you start. Takes 1-1/3 turns to complete.
Done
Actually doesn't matter where you start. Just follow the skip a cylinder pattern from wherever you start. Takes 1-1/3 turns to complete.
Last edited by Jesse Open; 06-29-2023 at 04:59 AM.
#3914

They time like doing three singles. Firing order is every other cylinder in turn. Start with #1 @ TDC, drop cam and carrier assembly in place just as with a single. Turn crank past #2 to #3, set that cam. Now turn to #2 and set that cam up.
Done
Actually doesn't matter where you start. Just follow the skip a cylinder pattern from wherever you start. Takes 1-1/3 turns to complete.
Done
Actually doesn't matter where you start. Just follow the skip a cylinder pattern from wherever you start. Takes 1-1/3 turns to complete.
I'd have mucked it up for sure....
Thanks Gary.
Love u man!
#3915
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I read most of the posts in this thread. It's a very interesting history of radials, at least since 2005 when this thread was started. Lots of info on Seidels, Technopower IIs, Saitos, ASP/Magnum 400s and UMS Evos among others. It's a great read for someone with interest in radials.
There are other observations beyond just the engines, those being the participants. I'm more on the collector side of things, not really in a position of which I can fly anything (which will change in five or six years). I can relate to stevesak, although I'm no where near his level insofar as engines are concerned. He's gathered quite a collection, much of it in a fairly short amount of time 10+ years ago. I aspire to achieve what he has done, but realize that I'll be taking a bit more time. The reason being it's a different world now than when he was going about gathering his collection.
I've managed to put together a humble collection of glow radials.
Technopower II A5
Technopower II C9
UMS Evo E735
UMS Evo E999
G-Mark 5 Cylinder
OS FR5-300
Robart R780
Of those, the one that has been run is the Technopower II A5. Looks like it was run few times, then put away without any afterrun care. It's currently torn down. I'll be putting it together again in the not so distant future. Overall it's in pretty good condition. It's S/N 005, so it's a very early example.
The Robart is a recent acquisition, from a member here. He very well could have listed the engine here at one point or another.
I also bought Profi ME Cirrus 4cc & 35cc (or is it 34?) V-8 engines. The ones based on Merritt Zimmerman's designs. Those I felt I should buy because I'm just not going to get a chance to buy engines like that often. I'm glad I did. The difference in scale of the engines looks somewhat bizarre when they sit next to one another. the Gnome (IIRC) referred to these engines as something 'ghost'. I can't recall exactly what. He had one. According to the Miniature Engineering Museum Collection there were less than 6 of the 4cc engines air cooled engines produced. I have no idea of how many of the larger engines there are.
I've been collecting for roughly 2.5 years. I bought some rather pedestrian stuff, then started looking for open rockers. Overall I'm not really interested in the two stroke engines so much. Four strokes are the vast majority of my collection.
I feel like I'm getting into this game at the end. Small engines like these fascinate me. There's not as much activity here nor on another site similar to this one regarding these engines. I wish there were. I'm not interested in Facebook, so if that's where the activity has gone I'm going to miss out on that.
There are other observations beyond just the engines, those being the participants. I'm more on the collector side of things, not really in a position of which I can fly anything (which will change in five or six years). I can relate to stevesak, although I'm no where near his level insofar as engines are concerned. He's gathered quite a collection, much of it in a fairly short amount of time 10+ years ago. I aspire to achieve what he has done, but realize that I'll be taking a bit more time. The reason being it's a different world now than when he was going about gathering his collection.
I've managed to put together a humble collection of glow radials.
Technopower II A5
Technopower II C9
UMS Evo E735
UMS Evo E999
G-Mark 5 Cylinder
OS FR5-300
Robart R780
Of those, the one that has been run is the Technopower II A5. Looks like it was run few times, then put away without any afterrun care. It's currently torn down. I'll be putting it together again in the not so distant future. Overall it's in pretty good condition. It's S/N 005, so it's a very early example.
The Robart is a recent acquisition, from a member here. He very well could have listed the engine here at one point or another.
I also bought Profi ME Cirrus 4cc & 35cc (or is it 34?) V-8 engines. The ones based on Merritt Zimmerman's designs. Those I felt I should buy because I'm just not going to get a chance to buy engines like that often. I'm glad I did. The difference in scale of the engines looks somewhat bizarre when they sit next to one another. the Gnome (IIRC) referred to these engines as something 'ghost'. I can't recall exactly what. He had one. According to the Miniature Engineering Museum Collection there were less than 6 of the 4cc engines air cooled engines produced. I have no idea of how many of the larger engines there are.
I've been collecting for roughly 2.5 years. I bought some rather pedestrian stuff, then started looking for open rockers. Overall I'm not really interested in the two stroke engines so much. Four strokes are the vast majority of my collection.
I feel like I'm getting into this game at the end. Small engines like these fascinate me. There's not as much activity here nor on another site similar to this one regarding these engines. I wish there were. I'm not interested in Facebook, so if that's where the activity has gone I'm going to miss out on that.
#3916

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People still fly glow, it’s just that gas has taken over the larger engine applications, and electric the smaller ones. The cost of fuel hasn’t helped, either. But there is such a variety of designs for glow, especially among the four-strokes. And that sound!
#3917
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I've read through various threads and have seen the discussions about gas being cheaper and less messy, or the convenience of flying electric. I can understand all of those points, and everyone is going to make their own choices. Can't fault them for choosing what works for them.
I suppose I was referring to the lack of discussions about glow engines. There just aren't nearly as many posts now as there were in years past. Such as in this thread - things really started tapering off around 2013. I'm active on another forum in a thread about glow engines, but there's not too much interest in the radials. It's more about 2 strokes. Those I'm not really interested in. That, and the guys that do have the big collections of the engines I'm interested in aren't posting very much at all. There are plenty of old threads from 10-15 years ago. Lots of great information to be had there.
#3918


The worst thing about glow radials is how much they rust internally. The larger the volume inside the crank case, the worse it seems.
My gas saito radial doesent have a speck of rust on the inside of it.
Glow fuel is getting really hard to get too.
It is a shame.
My gas saito radial doesent have a speck of rust on the inside of it.
Glow fuel is getting really hard to get too.
It is a shame.
#3919

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There are some nice looking four-stroke gas radials, from Moki, UMS and Saito. I see them on their websites, but don’t have any experience with them.
RCU seems to have fallen out of favor, I think because their classified section doesn’t work so well anymore. These days I spend more time on RCGroups and Flying Giants.
RCU seems to have fallen out of favor, I think because their classified section doesn’t work so well anymore. These days I spend more time on RCGroups and Flying Giants.
#3921

What do you expect to hear?
basically, it is completely the same design. Just scaled. 5 cyl, open Valves, intake through the crankcase, Same design ignition.
#3923

Gregg,
I am not the constructeur of the 400.
I had lots of 250´s here and two 400. Never operated one personally. One of them heavily destroyed ( sucked in and eat up its main bearing)
The construction is nowhere really different.
If someone says so, ask him for details and a few examples.
Otherwise it is just talk talk talk
-----------------
Of the Moki radials, I did operate one 150, a few 180s, one 215 ( good engine is serial number is above 800) and a few 250s, and one 300. Latest is the 300 in the Bearcat.
The latter is really a bit different from a 250 due to a different design in the intake area. It has tangential intake port case exits instead of radial ones like the 250. Unfortunately, this does not make it run more smoothly or evenly.
The 250 is in my eyes still the most mature engine of the 5-cylinder series with the fewest problems and the best all-round properties. Just my thoughts
Last edited by Detlef Kunkel; 09-19-2023 at 05:41 PM.