Club Silver Swallow
03-07-2015, 11:54 PM
#76
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Great contribution Chris. I hope you don't mind me saying that you are a mine of information on the unusual and rare in the model diesel world! Must catch up next time I am over there. Which is likely to be within the year.
03-09-2015, 06:01 PM
#78
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Stirling engine , flys well, had to cut it short as the backplate was loose
I would like to take it apart to see how it works
I would like to take it apart to see how it works
Last edited by 123Cat; 03-09-2015 at 08:25 PM.
03-09-2015, 06:36 PM
#80
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One more point that may contribute to why many of these Chinese diesels have a bad rap-EVERY new Yin Yan 2.47 I've had pass through my hands new has had the 7mm ID venturi insert fitted-the instructions say 'open the needle valve 5-7 turns for starting. This combination-with a normal tank height (ie roughly level with the spraybar) guarantees 2 things:
(1) The engine appears to have no suction and struggles to draw fuel from the tank and keep the fuel line filled-fuel often running back down the line towards the tank, and
(2) The engine floods readily in the event you can get fuel to the jet and choke it.
Put these two aspects together in inexperienced hands and you have a recipe for frustration and a reputation for 'difficult starting'-which is exactly what I had been told by others prior to getting my first one-and exactly what I encountered on my first bench running attempts. Fortunately I had enough nouse to recognise the problem-and by replacing the large venturi insert with the small one, and opening the needle a much more reasonable 3 turns only for starting, normal diesel behaviour ensued. I might also add I was stunned at how well the engine ran on the bench-not the slightest trace of any misfire-especially smooth running. Now I may have been lucky-I am after all thinking back more than 30 years-but I think I had a 9x4 Topflite nylon on it first up (though it might have been a 10-3/1/2 Topflite)
To paw080-Tony I am interested in hearing what the internal differences are between the Yin Yan and the Jin Shi nodels-can you elaborate?
ChrisM
'ffkiwi'
(1) The engine appears to have no suction and struggles to draw fuel from the tank and keep the fuel line filled-fuel often running back down the line towards the tank, and
(2) The engine floods readily in the event you can get fuel to the jet and choke it.
Put these two aspects together in inexperienced hands and you have a recipe for frustration and a reputation for 'difficult starting'-which is exactly what I had been told by others prior to getting my first one-and exactly what I encountered on my first bench running attempts. Fortunately I had enough nouse to recognise the problem-and by replacing the large venturi insert with the small one, and opening the needle a much more reasonable 3 turns only for starting, normal diesel behaviour ensued. I might also add I was stunned at how well the engine ran on the bench-not the slightest trace of any misfire-especially smooth running. Now I may have been lucky-I am after all thinking back more than 30 years-but I think I had a 9x4 Topflite nylon on it first up (though it might have been a 10-3/1/2 Topflite)
To paw080-Tony I am interested in hearing what the internal differences are between the Yin Yan and the Jin Shi nodels-can you elaborate?
ChrisM
'ffkiwi'
03-12-2015, 07:26 PM
#81
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I received a little Silver Swallow 1.47 "gold head" NIB with a couple of more highly thought of engines.
Feels pretty good. I can't get the back plate off with the supplied spanner. I will soak it in solvent and then warm the back of the case if needed. A peek inside before fire-up never hurts
*EDIT*
Ran it on the stand. It's a good one. No issues. Starts immediately hot and 4~5 flicks cold with a choked prime and compression backed off 1/8th of a turn.
Feels pretty good. I can't get the back plate off with the supplied spanner. I will soak it in solvent and then warm the back of the case if needed. A peek inside before fire-up never hurts
*EDIT*
Ran it on the stand. It's a good one. No issues. Starts immediately hot and 4~5 flicks cold with a choked prime and compression backed off 1/8th of a turn.
Last edited by fiery; 03-14-2015 at 06:50 PM.
03-15-2015, 07:35 PM
#85
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Great to hear that! Anything that takes young ones away from the PS3 or Xbox, and into a real hobby, is commendable. If he likes live steam he'll love diesel model engines.
03-09-2017, 02:02 PM
#88
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I now have 4 Silver Swallow 2.47's and one 1.5 .... The last received is not a match on the other 3 and now after reading this thread I suspect that the large venturi is to blame. The others are good starters and very good performers, whereas this one is hard to start but when tuned to nth degree actually has a few more revs, despite being a little softer on compression. So thanks guys, will make another smaller venturi for it to match the others.
03-09-2017, 06:02 PM
#89
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I have not Run the YIN YAN 2.47 shown above yet, and for exactly the same reason Ed. The dreaded 7 mm bore venturi insert.
Why the Teh Ming Sport Goods Factory Shanghai ever shipped a sport diesel engine with a pressure venturi as standard is baffling
.
I am having a 5.5 mm bore venturi insert made for the YIN YAN 2.47; and then we shall see how it performs. It feels really good.
Why the Teh Ming Sport Goods Factory Shanghai ever shipped a sport diesel engine with a pressure venturi as standard is baffling
. I am having a 5.5 mm bore venturi insert made for the YIN YAN 2.47; and then we shall see how it performs. It feels really good.
Last edited by fiery; 03-10-2017 at 12:28 AM.
03-09-2017, 07:18 PM
#90
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Adrian Duncan's treatise on the subject of all things Silver Swallow:
http://www.adriansmodelaeroengines.c....php?cat_id=74
http://www.adriansmodelaeroengines.c....php?cat_id=74
03-12-2017, 03:29 PM
#91
Ed and Fiery,
I also have several of these things. Several unrun, or briefly, on bench. One 40+ years old has quite a bit of time on it and all has been quite good. I have a few more, newer ones abandoned by a buddy; only one has been run and hasn't 'come in' yet. Must get back to it....
7mm is huge. Haven't miked the choke diameter on my sweet runner, or the others abandoned to me. 5.5mm works out to me as about .21" -(I'm still not native fluent in metric) Over the past few decades I played with some calculations to grossly estimate flow velocities through a venturii. Spraybar diameter is critical, of course. I have several times modified effective choke diameters in a very simple fashion.
Here in the USA, we have suppliers of Aluminum sheet and tube, sized at 1/32" (1.2mm or so?) intervals. The aluminum tubing is very soft. A slit lengthwise can allow a slightly oversize piece of alu tubing to be fit into the choke restrictor. The slit is where one side of the spraybar holes are located; they do not affect effective flow diameter.
The soft tubing can be stretched by i.e., a tapered punch or similar and/or filed out as needed to provide your chosen diameter.
Takes longer to describe than to do. I had a 'problem' PAW 35 single BB. Found irregular running, odd starting, etc., was likely due to the OEM choke having inner diameter greater than 6mm - came to about .265". That's larger than a stock Fox 35 Stunt choke! Replaced the PAW with a glow engine (several ounces lighter, too.)
With the choke reduced to .250" (6mm) the PAW seemed much happier on the bench. Haven't flown it on the same stunter, and likely won't.
The engine weight difference required a corresponding addition of tail weight to place the CG properly. So, another model for the PAW...
I'll review the (generic) Silver Swallows for appropriate choke diameter, and do what is indicated. The choke inserts in them seem to be the best finished fits - other than sleeve/piston - and I am concerned to find a non-destructive way to pull the insert for "amending as necessary."
I also have several of these things. Several unrun, or briefly, on bench. One 40+ years old has quite a bit of time on it and all has been quite good. I have a few more, newer ones abandoned by a buddy; only one has been run and hasn't 'come in' yet. Must get back to it....
7mm is huge. Haven't miked the choke diameter on my sweet runner, or the others abandoned to me. 5.5mm works out to me as about .21" -(I'm still not native fluent in metric) Over the past few decades I played with some calculations to grossly estimate flow velocities through a venturii. Spraybar diameter is critical, of course. I have several times modified effective choke diameters in a very simple fashion.
Here in the USA, we have suppliers of Aluminum sheet and tube, sized at 1/32" (1.2mm or so?) intervals. The aluminum tubing is very soft. A slit lengthwise can allow a slightly oversize piece of alu tubing to be fit into the choke restrictor. The slit is where one side of the spraybar holes are located; they do not affect effective flow diameter.
The soft tubing can be stretched by i.e., a tapered punch or similar and/or filed out as needed to provide your chosen diameter.
Takes longer to describe than to do. I had a 'problem' PAW 35 single BB. Found irregular running, odd starting, etc., was likely due to the OEM choke having inner diameter greater than 6mm - came to about .265". That's larger than a stock Fox 35 Stunt choke! Replaced the PAW with a glow engine (several ounces lighter, too.)
With the choke reduced to .250" (6mm) the PAW seemed much happier on the bench. Haven't flown it on the same stunter, and likely won't.
The engine weight difference required a corresponding addition of tail weight to place the CG properly. So, another model for the PAW...
I'll review the (generic) Silver Swallows for appropriate choke diameter, and do what is indicated. The choke inserts in them seem to be the best finished fits - other than sleeve/piston - and I am concerned to find a non-destructive way to pull the insert for "amending as necessary."
Last edited by Lou Crane; 03-12-2017 at 03:34 PM.
