30% nitro in a RCV120SP???
10-23-2009, 06:06 AM
#1
Senior Member
Thread Starter
My Feedback: (66)
Join Date: Jan 2008
Location: Bennettsville,
SC
Posts: 1,171
Likes: 0
Received 0 Likes
on
0 Posts
30% nitro in a RCV120SP???
I've been trying to tune a 120SP that I purchased used a while back. The previous owner said it was not fully broken in, but didn't say how long it had been run. I've run it for at least an hour and a half, and still wasn't getting a reliable idle , using 10% omega. I've seen the posts that say don't use more than 15% nitro, so I tried some 15% omega, and it performed a little better, however, when I turned the onboard glow off, it slowed down quite a bit and finally quit. I had some Omega 30% Heli fuel, so I tried a tankfull of that....it ran much better. It idled down much better and it didn't slow down at all when the glow was turned off. It obviously ran much better on 30%. My question to you guys is this; Will it harm the engine to run it on 30%, and if so, what should I do to get this thing to run right on 10%??
10-23-2009, 08:17 AM
#2
Member
Join Date: Aug 2007
Location: , AUSTRIA
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
I would assume higher vibrations and preignition with that high nitro.
Nitro enlarges the ignitable range of the fuel - air mixture. If the engine idles with high nitro but does not without, the idle mix screw needs adjustment. In your case it could be too rich.
Cheers
Andi
Nitro enlarges the ignitable range of the fuel - air mixture. If the engine idles with high nitro but does not without, the idle mix screw needs adjustment. In your case it could be too rich.
Cheers
Andi
10-23-2009, 10:00 AM
#3
Member
Join Date: Nov 2007
Location: sarnia, ON, CANADA
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
I would stay within the 10%-15% range, like you said it's not fully broken in yet. I have over 2 gallons of 10% run through mine with a reliable idle at 1500 rpm. It did take some time for the engine to loosen up and smooth out. I would also get a new OS type F plug. I think you might run into over heating issues with the 30%. Does it smoke allot at idle?
10-23-2009, 11:04 AM
#4
Senior Member
Thread Starter
My Feedback: (66)
Join Date: Jan 2008
Location: Bennettsville,
SC
Posts: 1,171
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
t smokes very little at idle with the 10%, but it does smoke a bit with the 30%. I've been running it some more this morning with 10%, and I can get the idle down to around 2000rpm, but it's running very rough.
10-23-2009, 01:07 PM
#7
Member
Join Date: Nov 2007
Location: sarnia, ON, CANADA
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
the carb should be set up to idle with a 1/16'' opening gap in the carb barrel. put a 1/16 drill bit into the carb opening and set the servo to idle at this setting. now you can adjust the low idle screw to find the sweet spot with good transition.
10-23-2009, 03:17 PM
#9
Senior Member
Thread Starter
My Feedback: (66)
Join Date: Jan 2008
Location: Bennettsville,
SC
Posts: 1,171
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
ok, did the 1/16 drill bit trick. The gap was at least twice too much to begin with. I'm getting closer every time I run it. I just hope the plane can handle the abuse. Looks like I'm gonna have to reinforce the firewall. It has almost vibrated loose. I re-glued it this time, but i doubt it will last. Oh, almost forgot...I also tried some fresh fuel,without extra castor( I add extra castor to most of my fuel), and it ran noticeably better. I'm guessing a couple more gallons of fuel, and it should be running like a new sewing machine.....I just hope the plane lasts that long. It wouldn't surprise me in the least to have a mid-air disentagration (sp) one of these days
10-29-2009, 11:53 PM
#10
Member
Join Date: Nov 2006
Location: royal oak,
MI
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
Hi scott ,
I have a 120 sp that runs great , smooth too !!! It started running great and smooth when I read that RCV started useing total synthetic oil and 10% fuel . When I switched to cool power 10% it was a whole different engine . Borrow a tank or two from a buddy and see for your self .
Guy.
I have a 120 sp that runs great , smooth too !!! It started running great and smooth when I read that RCV started useing total synthetic oil and 10% fuel . When I switched to cool power 10% it was a whole different engine . Borrow a tank or two from a buddy and see for your self .
Guy.
11-01-2009, 02:21 PM
#12
Senior Member
Thread Starter
My Feedback: (66)
Join Date: Jan 2008
Location: Bennettsville,
SC
Posts: 1,171
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
I bought a gallon of 10% Cool Power, and tried it yesterday in the 120......well kiss my[X(], it does run much better. I flew it several times with no issues at all. It still gets awfully hot, compared to my other 4-strokes, and there is dark gray/black oil "seeping" from the joints where the engine is put together. I'm hoping that it stays together[
]
]
11-01-2009, 04:27 PM
#13
Senior Member
Join Date: Dec 2007
Location: Killen,
AL
Posts: 185
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
It will stay together, Scott. Just keep running it and it will get smoother and smoother! As a precaution, I would check the tightness of all the screws occasionally.
11-01-2009, 05:08 PM
#14
Member
Join Date: Aug 2007
Location: , AUSTRIA
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
Hi,
yes it will stay together.
And yes, check the tightness of the screws. The oil from the joints is also normal, it will gradually decrease in the course of time as well as the oil from the front bearing (if any).
I do believe there is more than 15% oil in Cool Power, right? If you use 15% it will even run smoother.
´
Cheers
Andi
yes it will stay together.
And yes, check the tightness of the screws. The oil from the joints is also normal, it will gradually decrease in the course of time as well as the oil from the front bearing (if any).I do believe there is more than 15% oil in Cool Power, right? If you use 15% it will even run smoother.
´
Cheers
Andi
11-01-2009, 06:20 PM
#15
Senior Member
Thread Starter
My Feedback: (66)
Join Date: Jan 2008
Location: Bennettsville,
SC
Posts: 1,171
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
Great news, thanks I've got the engine in a Seagull SparrowHawk, swinging a 20x11 prop. ( I think that's right). I've got to admit, it sounds great on a low fly-by I was about to pull the engine and sell it. I'm glad I kept it now.
I've got the engine in a Seagull SparrowHawk, swinging a 20x11 prop. ( I think that's right). I've got to admit, it sounds great on a low fly-by I was about to pull the engine and sell it. I'm glad I kept it now.
11-02-2009, 03:43 PM
#17
Member
Join Date: Nov 2007
Location: sarnia, ON, CANADA
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
regarding the leak at the joint, mine does the same thing. don't worry about that. at least you know the bearings are getting oiled. there is a rubber O ring in there that might need replacing some time in the future. Glad to hear you got it figured out.
11-05-2009, 09:13 AM
#19
Senior Member
Thread Starter
My Feedback: (66)
Join Date: Jan 2008
Location: Bennettsville,
SC
Posts: 1,171
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
UPDATE....I have flown the SparrowHawk with the RCV120 several more times. While it is running better each time, it isn't enough power for the plane. Specs call for a 1.20-1.60 2-stroke or a 1.50- 1.80 4-stroke. While it does fly, it doesn't have the power to do much of anything but buzz around the sky....soooo, I've pulled it and plan to sell it. I'll probably replace it with an OS 160FX. Thanks again for all your help in getting it running right.
11-05-2009, 09:47 AM
#21
Senior Member
Thread Starter
My Feedback: (66)
Join Date: Jan 2008
Location: Bennettsville,
SC
Posts: 1,171
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
According to the owner's manual: Wingspan70.9", Wing area- 945.5 sq in, Approximate flying weight- 10.6-11.5 lbs, Length-61.3", Recommended engine size- 1.6 cu.in. 2-stroke, 1.8-2.0 cu. in. 4-stroke. I really thought it would fly the plane a little better than it does. I can't even get a complete loop out of it without it falling out.
11-05-2009, 12:00 PM
#22
Member
Join Date: Aug 2007
Location: , AUSTRIA
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
RE: 30% nitro in a RCV120SP???
Hi, thats interesting.
Well you removed the engine already otherwise I would have said try a different prop.
My Chester Jeep has the same span, is even a tad heavier and is pulled around with authority. Big loops from normal flight are no problem.
An APC 18/12 turns with around 5750rpm. I tried a lot of props, also e.g Master Airscrew. While they look good, the exemplar I tried was weak, the tracking was different, with full power
the blades bent forward. I tried a take off, but acceleration was so poor - and vibrations so high - that I discontinued.
With the 20/11 you mentioned you will have lower rpms due to the diameter and poor airspeed due to the low pitch. (The 20/12 is fine for a Piper Cub or similar, though).
So if you got a prop with poor quality and soft blades - that makes a difference.
regards
Andi
Well you removed the engine already otherwise I would have said try a different prop.
My Chester Jeep has the same span, is even a tad heavier and is pulled around with authority. Big loops from normal flight are no problem.
An APC 18/12 turns with around 5750rpm. I tried a lot of props, also e.g Master Airscrew. While they look good, the exemplar I tried was weak, the tracking was different, with full power
the blades bent forward. I tried a take off, but acceleration was so poor - and vibrations so high - that I discontinued.
With the 20/11 you mentioned you will have lower rpms due to the diameter and poor airspeed due to the low pitch. (The 20/12 is fine for a Piper Cub or similar, though).
So if you got a prop with poor quality and soft blades - that makes a difference.
regards
Andi
