RCG 26cc
03-21-2010, 12:49 PM
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RCG 26cc
I recently bought the RCG 26cc engine from Hobbyking (http://www.hobbyking.com/hobbyking/s...n_2.6HP/1.95kw). Since there does not seem to be another thread on this engine yet I'll start one.
The engine is affordable (cheap) at $140 and seems to be similar to the RCGF 26cc (an earlier version or a cheap knock-off not directly available in the US?). It arrived within 10 days, like every other order I've made from Hobbyking. The packaging seemed adequate, but somewhere along the line it received a bump on the cylinder head that bent one of the cooling fins. Since the packaging was not damaged, it probably happened before it was packaged. However, no other damage that would make it malfunction was apparent, so I decided to run it before attempting to send it back. This may be a consideration if you are comparing the RCGF vs the RCG. The RCGF will have local support, but it will be significantly more expensive at first. The RCG engine comes with a spark plug, electronic ignition (which works at 4.8-6V), engine stand-offs, exhaust and other mounting hardware. The instructions are inadequate to say the least. A complete novice might struggle a bit to figure out what it means. I think it is fair to say that if they completely omitted the instructions it would make almost no difference. Apart from the instructions the package was very complete. You only need a battery and prop to get going. I chose the 17x8 JXF prop from Hobbyking and I used a 2S LiFe battery for ignition with a BEC to limit the output voltage to 6V. The engine was installed into an Ultra Stick 120 Lite from Hanger 9. Installation was straight forward, no issues there. The plane balances on the recommended CG with the batteries and servos installed in the servo compartment.
This morning I ran the engine for the first time. I am 1000 ft above sea level. Temp was around 45 F and I used regular 87 octane unleaded gasoline with Echo-brand 2-stroke oil at 40:1 (I use the same mix in my edge trimmer, chain saw and two other gas rc engines, which keeps life simpler). The "instructions" claim that the needles were set at the factory so that it should start. However, the engine would not start at first and appeared to be set too rich, judging from the dense exhaust smoke when it fired. I discovered that the factory settings on the high and low ends were much too open at 4-5 turns out. I then closed the needles to the settings suggested in the "instructions", which was 1.25 turns on the low and 1.5 turns on the high. The engine still would not start and now appeared fuel-starved. After opening both needles about 2 turns the engine hand-started without any hassles. I used the typical approach of open throttle and closed choke until the engine popped, then open choke and 1/4 throttle, which resulted in the engine starting after another 5-10 flips of the prop. After the engine warmed up I tuned the top and bottom needles. It achieved a reliable idle of 2100 rpm and a consistent top rpm of 7200. I was impressed by the smoothness of the transition and it runs smoothly at any intermediate rpm. Next I hooked the plane up to a digital fish scale and got a static thrust of 13 lb 2 oz. I think this is very decent thrust for a brand new 26 cc engine. Running the engine for a while and using a better prop, such as a Xoar, will probably improve the thrust further, but at this stage I have no complaints.
The engine is affordable (cheap) at $140 and seems to be similar to the RCGF 26cc (an earlier version or a cheap knock-off not directly available in the US?). It arrived within 10 days, like every other order I've made from Hobbyking. The packaging seemed adequate, but somewhere along the line it received a bump on the cylinder head that bent one of the cooling fins. Since the packaging was not damaged, it probably happened before it was packaged. However, no other damage that would make it malfunction was apparent, so I decided to run it before attempting to send it back. This may be a consideration if you are comparing the RCGF vs the RCG. The RCGF will have local support, but it will be significantly more expensive at first. The RCG engine comes with a spark plug, electronic ignition (which works at 4.8-6V), engine stand-offs, exhaust and other mounting hardware. The instructions are inadequate to say the least. A complete novice might struggle a bit to figure out what it means. I think it is fair to say that if they completely omitted the instructions it would make almost no difference. Apart from the instructions the package was very complete. You only need a battery and prop to get going. I chose the 17x8 JXF prop from Hobbyking and I used a 2S LiFe battery for ignition with a BEC to limit the output voltage to 6V. The engine was installed into an Ultra Stick 120 Lite from Hanger 9. Installation was straight forward, no issues there. The plane balances on the recommended CG with the batteries and servos installed in the servo compartment.
This morning I ran the engine for the first time. I am 1000 ft above sea level. Temp was around 45 F and I used regular 87 octane unleaded gasoline with Echo-brand 2-stroke oil at 40:1 (I use the same mix in my edge trimmer, chain saw and two other gas rc engines, which keeps life simpler). The "instructions" claim that the needles were set at the factory so that it should start. However, the engine would not start at first and appeared to be set too rich, judging from the dense exhaust smoke when it fired. I discovered that the factory settings on the high and low ends were much too open at 4-5 turns out. I then closed the needles to the settings suggested in the "instructions", which was 1.25 turns on the low and 1.5 turns on the high. The engine still would not start and now appeared fuel-starved. After opening both needles about 2 turns the engine hand-started without any hassles. I used the typical approach of open throttle and closed choke until the engine popped, then open choke and 1/4 throttle, which resulted in the engine starting after another 5-10 flips of the prop. After the engine warmed up I tuned the top and bottom needles. It achieved a reliable idle of 2100 rpm and a consistent top rpm of 7200. I was impressed by the smoothness of the transition and it runs smoothly at any intermediate rpm. Next I hooked the plane up to a digital fish scale and got a static thrust of 13 lb 2 oz. I think this is very decent thrust for a brand new 26 cc engine. Running the engine for a while and using a better prop, such as a Xoar, will probably improve the thrust further, but at this stage I have no complaints.
03-21-2010, 05:47 PM
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RE: RCG 26cc
ORIGINAL: 52238
10cc = .60 so 20 cc is like a 1.20 30cc is like a 1.80
10cc = .60 so 20 cc is like a 1.20 30cc is like a 1.80
Then I have a Webra 120 and a YS-120 to replace. Same question. Which gas engine size to consider.
Help is definitely appreciated.
03-21-2010, 05:48 PM
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RE: RCG 26cc
Here are my impressions after the first day at the field, which included some static running of the engine, some taxiing, and about 45 minutes in the air, flying an Ultra Stick Lite 120.
The engine started easily every time and spooled up to top rpm without hesitation. I did not have to touch the needle settings. Fueled up the plane weighed 13 lbs and the engine pulled the plane around the sky with authority. I was pleasantly surprised when I pointed the nose straight up and the plane just kept climbing. Huge round loops were no problem. The static thrust would predict that it would barely pull the plane up vertically, but that was clearly not the case. Maybe the unloading in the air gives it a bit more useful pulling power. Whatever the reason, I am happy with the performance. I did some inverted flying, outside loops, snap rolls, spins etc., all with no problems from the engine. What impressed me too was the smoothness of transition and the lack of rough running at any rpm, similar to my experience on the ground. I seem to have hit the sweet spot on the needle settings early on with this engine.
My first impressions are extremely favorable. It is a cheap engine, but in use it does not act like a cheap engine at all. In fact, based on my initial experience with it I would probably use it in the same plane again if cost played no part in the choice. If this engine proves to be reliable it will be the best value I've come across in gas engines.
The engine started easily every time and spooled up to top rpm without hesitation. I did not have to touch the needle settings. Fueled up the plane weighed 13 lbs and the engine pulled the plane around the sky with authority. I was pleasantly surprised when I pointed the nose straight up and the plane just kept climbing. Huge round loops were no problem. The static thrust would predict that it would barely pull the plane up vertically, but that was clearly not the case. Maybe the unloading in the air gives it a bit more useful pulling power. Whatever the reason, I am happy with the performance. I did some inverted flying, outside loops, snap rolls, spins etc., all with no problems from the engine. What impressed me too was the smoothness of transition and the lack of rough running at any rpm, similar to my experience on the ground. I seem to have hit the sweet spot on the needle settings early on with this engine.
My first impressions are extremely favorable. It is a cheap engine, but in use it does not act like a cheap engine at all. In fact, based on my initial experience with it I would probably use it in the same plane again if cost played no part in the choice. If this engine proves to be reliable it will be the best value I've come across in gas engines.
03-21-2010, 06:07 PM
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RE: RCG 26cc
GGraham500,
I don't think there is a gas engine that will perform the same as an equivalent sized glow engine, especially at the lower end of the size scale where glow engines are common and have been developed to a state of exceptionally good performance. Maybe some of the newest gas engines from OS and Saito are different, but the typical small gas engine will almost certainly have a disadvantage to glow because of the extra weight needed for the carb and the ignition. I think that if the best possible performance in terms of power to weight is your primary goal then glow is probably still best. On the other hand, gasoline stores more energy per ounce, partly due to less need for lubrication, so you can fly longer on the same volume of fuel. Gasoline also weighs a little less for the same volume, so planes that are fueled up for a similar flight duration with gasoline and glow have less weight difference than you would expect based on dry weight. The Walbro carbs used on gasoline engines pump fuel, so you can place the fuel tank on the CG, which can be an advantage. Gasoline engines typically last longer and actually get better with age. Gasoline of course costs just a fraction of glow fuel, but it smells a lot worse. So, the bottom line, I think, is that gas and glow are different animals. It really depends on what you want.
If it is just the thrust of the 120 glow engines that you want to replace, you should probably look in the 26-30cc range of gas engines.
I don't think there is a gas engine that will perform the same as an equivalent sized glow engine, especially at the lower end of the size scale where glow engines are common and have been developed to a state of exceptionally good performance. Maybe some of the newest gas engines from OS and Saito are different, but the typical small gas engine will almost certainly have a disadvantage to glow because of the extra weight needed for the carb and the ignition. I think that if the best possible performance in terms of power to weight is your primary goal then glow is probably still best. On the other hand, gasoline stores more energy per ounce, partly due to less need for lubrication, so you can fly longer on the same volume of fuel. Gasoline also weighs a little less for the same volume, so planes that are fueled up for a similar flight duration with gasoline and glow have less weight difference than you would expect based on dry weight. The Walbro carbs used on gasoline engines pump fuel, so you can place the fuel tank on the CG, which can be an advantage. Gasoline engines typically last longer and actually get better with age. Gasoline of course costs just a fraction of glow fuel, but it smells a lot worse. So, the bottom line, I think, is that gas and glow are different animals. It really depends on what you want.
If it is just the thrust of the 120 glow engines that you want to replace, you should probably look in the 26-30cc range of gas engines.
03-22-2010, 10:02 AM
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RE: RCG 26cc
Hello propshaft, my experience has been very similar to yours except the needles were not that far
off, maybe a 1/4 to 1/2 a turn each. I also started a thread somewhere else:
http://www.rccanada.ca/rccforum/showthread.php?t=99258
Plenty of pics.. so far after 2 tanks of 14oz each (93 octane at 32:1) I'm getting these numbers:
Master airscrew classic 16x8 8750 rpm
APC 17x8 8250 rpm
My next try will be with an 18x6, the engine has not flown yet I'm currently installing it in a 108"
wingspan 7AC Champion.
Thanks for starting this thread, I will be following it and contribute what I can after it has flown.
off, maybe a 1/4 to 1/2 a turn each. I also started a thread somewhere else:
http://www.rccanada.ca/rccforum/showthread.php?t=99258
Plenty of pics.. so far after 2 tanks of 14oz each (93 octane at 32:1) I'm getting these numbers:
Master airscrew classic 16x8 8750 rpm
APC 17x8 8250 rpm
My next try will be with an 18x6, the engine has not flown yet I'm currently installing it in a 108"
wingspan 7AC Champion.
Thanks for starting this thread, I will be following it and contribute what I can after it has flown.
03-24-2010, 05:18 AM
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RE: RCG 26cc
Fullrudder, thanks for sharing the link to your review. Interestingly, your engine was packaged in a box with the "Viktor-fly" brand name on it. The same name was on the instructions. My engine was packaged in a box with no printing on it and I appear to have a different instruction sheet that also does not have a brand name printed on it. The engine itself looks the same.
03-24-2010, 09:03 PM
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RE: RCG 26cc
I did not measure weight on my engine. The following is 2nd hand from Full Rudder's review thread:
Engine: 987g
Muffler: 85g
Ignition: 109g
Hardware: 116g
Engine: 987g
Muffler: 85g
Ignition: 109g
Hardware: 116g
03-30-2010, 08:46 PM
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RE: RCG 26cc
Update:
My RCG 26 now has a little over a gallon through it. Most of that in the air. After the first few flights it ran rough and dead-sticked on me a couple of times. I traced the problem to an air leak in the fuel line (the plug on the fuel input end did not seal properly). After that was corrected there's been no problems. It now gives about 7280 rpm with a 17x8 JXF prop and idles at around 2000. I have not tried other props yet, but I like the performance on the JXF prop. The 13 lb plane has unlimited vertical. At full throttle it uses 0.65 fl oz of gasoline per minute. Battery use with a 2S LiFe battery regulated at 6V is around 500 mah per hour.
My RCG 26 now has a little over a gallon through it. Most of that in the air. After the first few flights it ran rough and dead-sticked on me a couple of times. I traced the problem to an air leak in the fuel line (the plug on the fuel input end did not seal properly). After that was corrected there's been no problems. It now gives about 7280 rpm with a 17x8 JXF prop and idles at around 2000. I have not tried other props yet, but I like the performance on the JXF prop. The 13 lb plane has unlimited vertical. At full throttle it uses 0.65 fl oz of gasoline per minute. Battery use with a 2S LiFe battery regulated at 6V is around 500 mah per hour.
04-11-2010, 02:35 PM
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RE: RCG 26cc
JXF 17x8 prop failure!
Watch out for JXF props from Hobbyking. The prop split lengthwise on one side for no apparent reason. The prop had not been damaged previously in any way that was visible. It caused an "unscheduled landing" out in the shrubs, but luckily not much damage to the plane. Vertical performance is down slightly after changing to a 17x8 APC Pattern prop. I intend to try a Xoar prop next. Has anyone had experience with 18x6 props on this engine?
The RCG 26 engine is still performing flawlessly though. I did some recordings of battery use. It takes about 330mah to recharge the battery after an hour's run time using mixed throttle settings typical of flying.
Watch out for JXF props from Hobbyking. The prop split lengthwise on one side for no apparent reason. The prop had not been damaged previously in any way that was visible. It caused an "unscheduled landing" out in the shrubs, but luckily not much damage to the plane. Vertical performance is down slightly after changing to a 17x8 APC Pattern prop. I intend to try a Xoar prop next. Has anyone had experience with 18x6 props on this engine?
The RCG 26 engine is still performing flawlessly though. I did some recordings of battery use. It takes about 330mah to recharge the battery after an hour's run time using mixed throttle settings typical of flying.
04-11-2010, 06:39 PM
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RE: RCG 26cc
I had a similar failure with a MAS WOOD prop last summer, only I caught it early as I was swapping props around seeing which worked better at the time. It was coming apart just outside the spinner.
Regarding the APC, have you tried the "w" (wide) series? I'm running one of those on my RCGF 26, (18x6w) was turning 7800 today. I would rate performance very good. Will accelerate from a hover or while vertical w/10.5 lb Funtana.
Regarding the APC, have you tried the "w" (wide) series? I'm running one of those on my RCGF 26, (18x6w) was turning 7800 today. I would rate performance very good. Will accelerate from a hover or while vertical w/10.5 lb Funtana.
04-25-2010, 11:49 AM
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RE: RCG 26cc
Update:
I checked the rpm again using an APC 17x8 Pattern prop. After close to 2 gallons of fuel, it now turns at 7620 rpm (up from 7280 previously), using Echo synthetic oil at 40:1 in 87 octane gasoline. Useful power in the air is also visibly better. Reliability is still solid. I've not had a single dead stick after I fixed an air leak in the fuel line early on. Smooth at any rpm. Battery use is now consistently around 330 mah per hour (the 500 mah per hour I obtained at first may have been related to the performance of the new battery I used, which may not have taken a complete charge in the first cycle). I'm getting another one of these engines for a WW1 1/4 scale biplane.
I checked the rpm again using an APC 17x8 Pattern prop. After close to 2 gallons of fuel, it now turns at 7620 rpm (up from 7280 previously), using Echo synthetic oil at 40:1 in 87 octane gasoline. Useful power in the air is also visibly better. Reliability is still solid. I've not had a single dead stick after I fixed an air leak in the fuel line early on. Smooth at any rpm. Battery use is now consistently around 330 mah per hour (the 500 mah per hour I obtained at first may have been related to the performance of the new battery I used, which may not have taken a complete charge in the first cycle). I'm getting another one of these engines for a WW1 1/4 scale biplane.
05-07-2010, 11:41 AM
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RE: RCG 26cc
I am running my engine in a APC 17-8 it is making 7500 rpm Need more vertical climb, what if I install a 16-10 propeller, this can help?
the aiplane is a yak 54 from nitromodels.
E. Roesch
Guatemala
the aiplane is a yak 54 from nitromodels.
E. Roesch
Guatemala
05-08-2010, 07:34 AM
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RE: RCG 26cc
Hi all, I've just recieved my RCG 26 from Hobby King. I plan on
installing it in a 1/4 scale Cub. Thanks to all for the initial reports
on this engine which sound good. I'll be posting my results as well.
Stick2K
installing it in a 1/4 scale Cub. Thanks to all for the initial reports
on this engine which sound good. I'll be posting my results as well.
Stick2K
05-10-2010, 08:10 AM
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RE: RCG 26cc
ORIGINAL: Stick2000
Anyone know if there is a wrap around Pitts muffler for
the RCG 26 ?
Stick2K
Anyone know if there is a wrap around Pitts muffler for
the RCG 26 ?
Stick2K
05-10-2010, 03:27 PM
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RE: RCG 26cc
Thanks for the info. I'll contact Jtech. Does JTECH have a web site?
Stick2K
Stick2K
ORIGINAL: ahicks
I had JTEC make one up for me. Maybe a gallon through it so far, and no trouble with it. Good looks, performance, and very reasonable noise level. -Al
ORIGINAL: Stick2000
Anyone know if there is a wrap around Pitts muffler for
the RCG 26 ?
Stick2K
Anyone know if there is a wrap around Pitts muffler for
the RCG 26 ?
Stick2K
05-10-2010, 08:13 PM
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RE: RCG 26cc
http://www.jtecrc.com/wraparoundpittsstylemufflers.htm
Phone (704) 799-1658 Fax (704) 799-1678
Email: [email protected] or