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Offline RandySmith

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Engine tuning tips
« on: January 07, 2010, 02:18:40 PM »
 From a PAMPA article

Randy Smith
1047 Sawgrass CT  SW,
Lilburn, Georgia, 30047
(678)407-9376

randyaero@msn.com                    The Golden Age of Stunt
 I’ve known we are living it; however, while at the VSC 18, this thought was solidified. The Golden Age of Stunt is Today. At no time in history did we have more planes, motors, props and all the stuff we use. It is amazing the amount of choice that is available to every stunt flyer.
From Laser cut Old Time and Classic kits to modern AAC motors to the light , super strong Carbon Fiber items that seem to grow out of the woodwork everyday.
The planes were absolutely stunning and comparing motor runs to 30 years ago, well suffice to say “no comparison”.
I have been asked many times lately to explain how to setup an engine for a good “stunt run”. All too often I see motors running backwards from the ideal. Four stroking up hill and breaking into a 2 stroke downhill, going blubbery rich on insides, screaming lean on outsides, etc, etc.
I would like to talk about the basics for setting up your engine to get a better machine. Someone once said a good stunt ship is 40% design, 60% motor. The performance of some of the airplanes at VSC proved this is true.
In a nutshell:
Remember the needle is for setting the fuel mixture, not for setting the plane speed.
The prop pitch is for setting the speed of the airplane.
The prop diameter is for loading the engine properly and getting maximum thrust from the motor.
Nitro is for controlling how much or how little break you have, this is to say how strong the motor will come on in the maneuvers. The other 2 items that work with this are compression and venturie size. This is not all there is to getting perfect engine runs. Many things work in
conjuction with each other to achieving this goal, and most everything I am going to mention affects the others to some degree or another. Please do not think of the following as an oversimplification, it is not. It would take a volume of text to try to explain all the relationships that one item has to another, this is just to try to add a little clarity, and to give you a place to start.
The 8 basics to helping yourself to a better engine setup are:
1. Engine: Pay careful attention to matching the engine to the airframe. Don’t overpower or under power your plane. Make sure your power plant is an acceptable weight for the ship it is in and matches well with it
2. Correct Fuel: Fuel is one of the most important things in tuning an engine. You must make sure that you have the correct oil type and percentage for the engine your using. For example Fox 35s, OS 35s, older McCoy’s and such need high oil content fuels 24 to 29% are common percentages.
Modern ABC and AAC engines will use much lower oil, 18 to 22 % percentages are the norm here. Nitro percentage is also key to getting the best from your power plant, There are so many ways to run stunt engines it is impossible to print anything but guide lines.
I have written many times about fuel. You can get a copy of my Care and Feeding of a Stunt Engine from the PAMPA archives
Typical stunt engines will use 5% nitro in cold weather going to 10 or even 15% in hot months. You can get in trouble using, say 15% in January, this setup would need 25% or more to be the equivalent in August. So unless you really have this working it is best to setup your engine for lower nitro in cold months and higher nitro in hot months. This will help keep the run constant thru out the year. Also it will help control power in your motor.
3. Correct Props: Props are also critical for achieving good engine runs; a prop needs to “load” the motor correctly without over or under loading the motor. It also needs to be the correct size and pitch to pull the airplane. This is an over simplication, but generally the diameter will be what you use to “load” the engine and the pitch will be what you pick to set the plane speed
Some of the things you will run into when over propping an engine are; hard to set the needle on the ground; the engine will unload a lot and go rich in the air; the engine will run hot, or not cycle very rapidly.
When under propping generally you will notice the engine will also not cycle correctly. They at times will just 4 stroke thru everything, sometimes going into a 2 cycle at weird times.
A properly loaded engine will use a prop that if running a 4-2 break, will come onto a 2 stroke a 10 O’clock and back to a 4 at 2 O’clock. There are variations on this; You can have a strong motor just beep 2 stroke at the tops of maneuvers, but you shouldn’t have one that 4 strokes uphill and switches to a 2 stroke on the downhill parts of maneuvers.  You can setup the run with a very strong 4 cycle that doesn't break anywhere, but will still cycle and increase/decrease power in maneuvers somewhat, don't try to get so deep into a 4 cycle that the engine goes even richer when starting a maneuver, or slows ans speed in weird places, generally this setup should still be in a high power setting that is close to the 2 cycle beep without going into a 2cycle.
4. Needle setting: Don’t try to use the needle to set the speed of the airplane; the needle is for setting the fuel-air ratio that goes into the engine. Typical settings are so the motor will be in a very fast 4 stroke when in level flight. If you set the needle too rich it will delay the engine switching and make the engine come on late in the maneuvers. If you set it too lean, you can sometimes run the risk of too much 2 stroke and going sagging lean in the tops of maneuvers, killing your drive and over heating the engine. Once you get this set, you will have a little leeway in tweeking the needle in or out for conditions.
5. Airspeed: Most all planes like to fly at the airspeed they work best in, even exact or what is supposed to be the exact same design , will a lot of times want to fly at different lap times. Example: I have flown many SV-11s, at the same weight that fly at different speeds. Try to find the optimum speed for the plane your flying. This will depend a lot on the weight of the plane and also the power of the engines
6. Compression: Setting the correct compression for you motor isn’t a simple thing and will vary with nitro and prop size. Try to set the compression so when your engine hits into a 2 stroke it doesn’t come on too hard or too soft. This will work in conjunction with nitro and venturie size. Generally you will use higher compression for low nitro and lower the compression when using higher nitro fuels.
7. Venturi : Venturi size is one of the keys to get a proper switching 4-2, while not coming on too hard or too soft or too late or too early. If you are constantly accelerating too much when your engine cycles you may need to go down on venturi size. If you are not cycling much or have too soft of a break or a late break , you may need to open the venturi up a size or 2. This will work in direct relationship to nitro and compression.
8. Fuel Tanks: A large portion of engine problems I see are really not engine problems. They are fuel delivery problems that many times relate to fuel tanks, Tanks are maybe the most critical component of your power train. Make sure you have a solid mount, and a tank with no leaks or cracks in the tubing, inside or out. When in doubt I suggest trying a new tank, if there is a difference, you may have bad tank. Don’t forget to use a good filter and make sure there are no holes in the fuel tubing. It is also advisable to try to keep the tank as close to the engine as possible
These are just basic suggestion to help you tune your engine, and by no means covers it all. There are literally thousands of engine setups that would take volumes to cover.

Randy Smith
 
« Last Edit: February 25, 2018, 09:22:54 PM by RandySmith »


Offline Rafael Gonzalez

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Re: Engine tuning tips
« Reply #1 on: December 16, 2010, 08:54:19 PM »
Hello!


Just joined. Excellent info site. Perhaps it has been discussed before but I can not find it under the search application. I can see that I will be absorbing like a sponge in here... Being a combat flyer for most of my life and a part time R/C crasher (can't stay away from the T=0 part of the formula), I am starting to tinker with the C/L stunt. Several questions I have(spoken as a well known Star Wars character)
All the obvious aside,
I see that many convert the heads of engines to a hemi configuration. Question 1:
A hemi was intended to increase the compression of a piston and to reenforce the top as the main purposes, due to the violent detonation that ocurrs. On a typical head for a model engine, there is a squish band with a small area for combustion. Is the purpose of a hemi conversion to decrease the compression ratio for stunt and allow the gases from the intake port on the liner to better flow once it reaches the curve on the head (turbulence). I see that in most cases the loss is not compensated by lowering the head or shaving the liner.

Question 2:
Is there any difference in timing between a ST V.60 R/C and an ST V.60 C/L Intake/exhaust/boost? What should they be for stunt?I just got my hands on a new ST V.60 R/C.
A stunt newbie

Best Regards,
RAFAEL
 

Offline Joe Mig

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Re: Engine tuning tips
« Reply #2 on: December 17, 2010, 05:33:32 AM »
This is great info and a big help,thanks Randy.  H^^

Offline RandySmith

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Re: Engine tuning tips
« Reply #3 on: December 17, 2010, 02:40:48 PM »
Hello!


Just joined. Excellent info site. Perhaps it has been discussed before but I can not find it under the search application. I can see that I will be absorbing like a sponge in here... Being a combat flyer for most of my life and a part time R/C crasher (can't stay away from the T=0 part of the formula), I am starting to tinker with the C/L stunt. Several questions I have(spoken as a well known Star Wars character)
All the obvious aside,
I see that many convert the heads of engines to a hemi configuration. Question 1:
A hemi was intended to increase the compression of a piston and to reenforce the top as the main purposes, due to the violent detonation that ocurrs. On a typical head for a model engine, there is a squish band with a small area for combustion. Is the purpose of a hemi conversion to decrease the compression ratio for stunt and allow the gases from the intake port on the liner to better flow once it reaches the curve on the head (turbulence). I see that in most cases the loss is not compensated by lowering the head or shaving the liner.

Question 2:
Is there any difference in timing between a ST V.60 R/C and an ST V.60 C/L Intake/exhaust/boost? What should they be for stunt?I just got my hands on a new ST V.60 R/C.
A stunt newbie

Best Regards,
RAFAEL
 

Hello Rafael

Yes when people cut hemi shaped into the heads they lower the C/R, many use larger venturies to try to make up the differance in power

The RC and CL versions of the ST 60 are both exact same in timing

Regards
Randy

Offline Rafael Gonzalez

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Re: Engine tuning tips
« Reply #4 on: December 17, 2010, 08:13:08 PM »
Very much appreciated for your time, Sir!
Thank you!

Rafael

Offline David_Ruff

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Re: Engine tuning tips
« Reply #5 on: February 08, 2014, 06:39:22 AM »
I will ask my dumb question here about the 4-2 break. What causes the break?  Is it the leaning of fuel mixture?  If so, how does that happen?  In a perfect world the fuel mixture should not change with a fixed system? 

Offline RandySmith

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Re: Engine tuning tips
« Reply #6 on: February 08, 2014, 10:48:48 AM »
I will ask my dumb question here about the 4-2 break. What causes the break?  Is it the leaning of fuel mixture?  If so, how does that happen?  In a perfect world the fuel mixture should not change with a fixed system? 

Hi David , it is a combo of things, load and mixture, the fuel head does change, as well as load when the airplane is in maneuvers, to see for yourself, run an engine on the bench, set it just in between a 4 and 2 cycle, raise only the tank up higher, then lower the tank only lower than the engine, you will see the engine go richer and leaner. you just changed the mixture.

Randy

Offline Andy Bush

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Re: Engine tuning tips
« Reply #7 on: May 13, 2015, 06:13:44 AM »
This info is the best!

I never realized how little I know about this hobby...here's my stupid question!

What is meant by the 2-4 cycle reference? The same as for lawn mower engines, for example? Or is it just a reference to the engine running at different speeds?

Andy

Offline RandySmith

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Re: Engine tuning tips
« Reply #8 on: May 14, 2015, 10:39:23 AM »
This info is the best!

I never realized how little I know about this hobby...here's my stupid question!

What is meant by the 2-4 cycle reference? The same as for lawn mower engines, for example? Or is it just a reference to the engine running at different speeds?

Andy

Hi Andy
When you richen the needle setting on a 2 stroke model airplane engine, it will drop its sound tone,go into a misfire every other evolution and will be in a "4 cycle", when you lean the mixture out it will sound like it cleans up , normally sound like it just "jumped" into a faster RPM, and is now in a 2 cycle mode ( firing every revolution} higher the 4 cycle sound lower volume/pitch , the 2 cycle sounds higher volume/pitch.
You can may times hear this if holding the plane while running, and turning the nose of the plane up and down.

Randy

Offline RknRusty

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Re: Engine tuning tips
« Reply #9 on: May 15, 2015, 05:18:54 PM »
Am I correct in my thinking that when it's right on the edge, the RPM stays nearly the same as it breaks back and forth from 4 to 2? Yet the torque must increase when it breaks into 2 stroke, giving it the ability to climb with more authority?
Rusty
DON'T PANIC!
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while you're doing it!

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www.coxengineforum.com

Offline RandySmith

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Re: Engine tuning tips
« Reply #10 on: May 18, 2015, 08:24:45 AM »
Am I correct in my thinking that when it's right on the edge, the RPM stays nearly the same as it breaks back and forth from 4 to 2? Yet the torque must increase when it breaks into 2 stroke, giving it the ability to climb with more authority?
Rusty

Many times yes, however I have seen people setup a 4/2 were it slows when going into a 2 cycle, then some have it set where it speeds up greatly, best setup on a 4/2 is when you get a modest boost that keeps the plane near the same speed, RPMs may not increase because your most times putting extra load, on the engine, and going thru corners, and going vertical, all try to slow the RPMs, what your doing there is adding extra power/torque to help keep the speed the same

Randy

Offline Richard Lotspeich

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Re: Engine tuning tips
« Reply #11 on: December 21, 2017, 08:46:21 PM »
Hi Randy
I have an old OS 40 SF with bearings and I believe rings. I haven't run it in so many years that I can't remember what kind of a stunt engine it was. I don't believe it was a favorite and I have heard many bad things about this motor. Is it a good stunt motor? Should I put it in a plane or on the shelf. What do you think?
Dick Lotspeich

Offline RandySmith

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Re: Engine tuning tips
« Reply #12 on: December 21, 2017, 10:00:29 PM »
Hi Randy
I have an old OS 40 SF with bearings and I believe rings. I haven't run it in so many years that I can't remember what kind of a stunt engine it was. I don't believe it was a favorite and I have heard many bad things about this motor. Is it a good stunt motor? Should I put it in a plane or on the shelf. What do you think?
Dick Lotspeich
Dick if I remember correctly  they did not make a  ringed  SF  stunt engine, the ring one was  RC,  the  2  stunt engines  40 and 46 SF-S  has  that stamped on the crankshaft,  you may want to remeove the back plate and look
I can also tell you the  46 was  much better than the  40

Randy

Offline Richard Lotspeich

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Re: Engine tuning tips
« Reply #13 on: December 22, 2017, 10:53:33 AM »
Hi Randy
I looked inside the os 40 sf and it does not have the sf-s stamped there, only sf-. I have no idea about the different way motors are built. Will this one not run for a stunt pattern.
Thanks
Dick Lotspeich

Offline RandySmith

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Re: Engine tuning tips
« Reply #14 on: December 22, 2017, 03:31:45 PM »
Hi Randy
I looked inside the os 40 sf and it does not have the sf-s stamped there, only sf-. I have no idea about the different way motors are built. Will this one not run for a stunt pattern.
Thanks
Dick Lotspeich

If you use it  run it in a  wet  2 cycle, you have an RC version there

Randy

Offline Richard Lotspeich

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Re: Engine tuning tips
« Reply #15 on: December 22, 2017, 04:09:09 PM »
Thank you Randy
Actually, not being able to run a 4-2-4 is one of the drawbacks  I heard about the SF. I think I will run it as you suggested and use less pitch prop.
Dick

Offline Ryan_McFadden

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Re: Engine tuning tips
« Reply #16 on: June 10, 2019, 11:50:40 PM »
     I'll start at the beginning here; A few months ago a friend gave me and old Fledgling 56" with an Enya 35-III 5224 and a Kraft Bicentennial Series TX/RX and servos. I have sent the TX/RX to Radios South for an up grade and mod to bring it into current Regulations. This plane sat and was move a bunch of times over the last 35+ years and had a bit of hangar rash. I learned ( through many hours of You Tube ) how to re cover it, and as an Aircraft Mechanic I already knew how to repair any damage to the structure. At this point I am waiting for the electronics to come back. Through all of this I have learned that I know nothing about these engines, how to set them up, how they truly run, or most importantly what to do with them. The engine currently has an old Top Flight wooden 10-6 prop on it, and as far as I know it was broken in years ago. I did pull it apart and clean it up, put a new gasket, crankshaft and screw kit in it, all bought directly from Enya as it was much cheaper then eBay. I have been running it on " Cool Power" 10% total synthetic fuel, because that is what the local hobby shop sold me, however I feel that this engine can do better. Since there are no clubs near me I have to turn to the internet for answers. I have found a lot of great information on this forum so I joined to get all of the nitty details that I need to operate this plane correctly and safely. My goal here is to have it air borne in the next month or so and the engine was giving me some... issues. either it will die at throttle wide open and idle great, or not idle and run wide open with a lot of smoke. In tinkering with the idle air bleed and main needle setting I just last night was able to get her running and responding to throttle input on my test stand ( once I figured out that location of the fuel tank actually matters ). A few questions that I have are the switching 2-4 stroke, what exactly is going on, why it does it, how is  it controlled and when should it take place? As far as actually flying the craft I'm hoping that my many hours as a pilot will assist me here, and of course baby steps so I don't turn it into a smoking hole on the first flight. SO and tips/tricks info or advice is very welcome and much appreciated.

Offline Dave Hull

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Re: Engine tuning tips
« Reply #17 on: June 11, 2019, 04:03:13 AM »
Ryan,

Hope your hobby efforts are a lot of fun. Here's a bit to think on, and hopefully Randy will amplify or correct anything he feels isn't quite right.

It would not surprise me that many of your engine issues are the result of your fuel. The 10% Morgan Cool Power All-Synthetic is not the best fuel for that engine. It is an old-metallurgy design, and not a modern ABC type engine that can make use of modern fuel mixes. I believe the Enya III has a steel liner which is far better off with some castor oil in the mix. (Read Randy's opus here on fuels for older engines.) The Cool Power also is only 17% oil. If your engine is one of the older III models with plain bearings and not ball bearings, that is another reason you need more oil in the mix. If it were my engine, I would be using 25% oil and probably 3/4 of that would be castor. Changing the oil ratio will change the required carb settings, so switching around the fuels will mean resetting the carb. If you had to make significant adjustments, that may be one reason why.

I've heard too many stories about hobby shops and fuels. They want to sell something that they have, not something that you have to order. And they may not have any experience running older engines. A lot of guys are too young to have run anything that wasn't chromed, ABC or nowadays ABN. So they may not know.

Note that I am not knocking the Enya at all. They made, and still make, some really great engines. They are known for being extremely durable when operated properly.

A 10x6 propeller is in the right ballpark for an Enya .35. Be sure to have a few spares (landing issues) and be sure any older props are not cracked, chipped or brittle.

The vertical center of the fuel tank should be in the same horizontal plane as the needle valve in the carburetor.

Don't count on full scale flying experience helping you much (any?) with flying an R/C model successfully. It won't. Rather, it tends to give guys false confidence that they should be able to fly a toy, since they already know how to fly the real thing....  (I am a private pilot, so presumably know somewhat of what I speak.)

What does really help is flying on a computer R/C flight simulator. It will get you used to seeing the plane coming towards you, where you will find that the "controls are reversed." That is the usual cause of several wrecks before you get the hang of it.

Of course, the best of all worlds is to get some time on the simulator and then fly with an instructor on a buddy box. I remember that I chose to try to teach myself how. I had my fair share of wrecks--mostly with gliders--which are far slower than power planes and give you more time to think.

Wishing you success with your equipment and your flying,

Dave

Offline Brett Buck

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Re: Engine tuning tips
« Reply #18 on: June 11, 2019, 09:58:29 AM »
Don't count on full scale flying experience helping you much (any?) with flying an R/C model successfully. It won't. Rather, it tends to give guys false confidence that they should be able to fly a toy, since they already know how to fly the real thing....  (I am a private pilot, so presumably know somewhat of what I speak.)

What does really help is flying on a computer R/C flight simulator. It will get you used to seeing the plane coming towards you, where you will find that the "controls are reversed." That is the usual cause of several wrecks before you get the hang of it.

Of course, the best of all worlds is to get some time on the simulator and then fly with an instructor on a buddy box. I remember that I chose to try to teach myself how. I had my fair share of wrecks--mostly with gliders--which are far slower than power planes and give you more time to think.

   I am not a particularly good RC pilot, but I can get them up and down, and this advice is pure gold. Having flown the real thing is very frequently a negative, both from the self-confidence perspective (it gives you a false sense of security), and a skills perspective. It's fundamentally different skill set. There wasn't such a thing as a simulator when I did it, and I had no help, so I crashed many times. Simulators would have resolved the left/right issue, but even RC cars would help tremendously.

   As with anything, it is worth a lot of effort to fly with other experienced pilots, even it it involved extensive travel. Be aware, however, that an awful lot of people flying RC consider themselves experts, whether they are or not.
   
    Brett

Offline Ryan_McFadden

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Re: Engine tuning tips
« Reply #19 on: June 11, 2019, 04:32:28 PM »
Dave and Brett, thank you both for the info. I will look into finding a better source for a more consistent fuel for this old engine, it is in fact a steel liner, non-roller bearing crank and square carb. As best as I can tell it was made in the end of the 60's to early 70's. I have also read of people mixing their own fuel, anything good come from this? I have read mixed reviews. would it be feasible to add to the fuel I have on hand or should I use it as a fire starter and buy something better?.. seems the more I learn about this hobby the more questions I have.. And yes I'm have having a blast fixing and tinkering with this old bird, my wife however... not so pleased  ;D. As far as actually fling it I was planning on taking it in small steps at first, low and slow. however I would love some sim time IF I can find any close to me.
Thanks again!

Online Dan McEntee

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Re: Engine tuning tips
« Reply #20 on: June 11, 2019, 06:14:29 PM »
   Hi Ryan;
     At first I thought your post was a trip back in time! I didn't know Radio South was still around in today's radio environment, and the mention of Kraft radios may have some thinking they only made cheese!
     First, the Enya engine. Great engines, and are made of quality metal and machining, but are notorious for taking a long time to break in. If you are static running the engine on a test stand or just in the fuselage, you may want to drop down an inch or two on pitch just to take some load off it it isn't broken in. Then repeat your throttle testing.
   Been a while since I have seen that vintage carb, but it may have a high speed and low speed needle. You need to know which is which. The low speed needle is for what the name says, setting mixture at low speeds, bit it influences the mixture up to 3/4 throttle. If you make adjustments, make small ones and give it time to adjust to that. If it blubbers when you advance the throttle, lean it a click or two and try again. If it hesitates and or dies, it's lean and needs to be richened up a bit. You may need the original instructions to tell which way to turn the needle. If you tart to get it lined out, peg the throttle and see how it runs at full throttle, or high speed. Turn the high speed needle and see how it reacts. You want to stop adjusting just as it breaks into a clean two stroke, and maybe back off a click or two. The mixture will lean out in the air, so you need to allow for that. If you are happy with high speed, then finish you low speed adjustments until you get a clean transition.
    If you have Cool Power, your hobby shop may also carry Omega, as it is made by the same people, Morgan Fuels. Get a gallon of that and add about 4 to 6 ounces of castor to it. Omega is a castor/synthetic mix and will accept it. ^ ounces will get you near the 20% total oil threshold I think. You may be able to add oil to the Cool Power, but I haven't tried it to see if that green synthetic will blend with castor. Try adding a table spoon of castor to a couple of ounces of Cool Power and see what happens. If it mixes and doesn't separate, you may be in business. Once you get the idle and transition set, run at least four tanks of fuel through it with the flatter prop and observe the exhaust to see what color the oil is coming out. If it's clear, you are getting broke in, and you can go back to the 10-6 prop for flying, but you nay have to adjust the needles a bit again. If you have a big temperature change, you will need to adjust the needles again for the temp difference. This is all old school stuff and in Two Stroke 101 books!
  Good luck with it and enjoy the airplane and the experience.
  Dan McEntee
AMA 28784
EAA  1038824
AMA 480405 (American Motorcyclist Association)

Offline Dave Hull

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Re: Engine tuning tips
« Reply #21 on: June 12, 2019, 12:43:32 AM »
Ryan,

Regarding mixing your own fuel:  If you can purchase the correct ingredients, and you have the ability to measure, and you trust your ability to keep track of what you already put in--then mixing fuel is simple. Not as easy as pouring a bowl of corn flakes, but easier than baking a cakemix.

The only real hassle can be getting the right ingredients. In some locations, this is easy. The nitro is the most expensive component and likely to be the most difficult to get. Once you get a source lined up, it shouldn't be a big deal. Note that with the nitromethane and the methanol, there are shipping restrictions that tend to make things harder and more expensive. Fuel is often shipped in quarts instead of gallons to avoid additional restrictions. Go figure the brilliance of that....

Because some guys either can't get all the ingredients, or because they find it even easier to "doctor up" a commercially available fuel they start with something they can buy. Such as Dan's suggestion to start with Omega and add caster oil. Typically, you would purchase Bakers castor from SIG model company, or Benol from Klotz. Either works fine. Don't worry about the color, that's just dye. If you want to add some synthetic to a scratch  brewed fuel, I would suggest using Klotz Original Techniplate which runs about $14-15 a quart. If you are doctoring fuel that already has some synthetic oil in it, don't add more synthetic--only add castor. And yes, the percentage of nitro in the mix will go down, but not very much, and your engine should run fine on less than 10% nitro. We do it all the time.

If you do not want to do the math to figure out the percentages, there is an on-line calculator here somewhere that is pretty accurate.

Did you read Randy's pinned post on fuel yet? He talks about engines with steel liners, plain bearings, and unbushed rods and why he recommends 26 to 28% oil content. Your application is R/C, but for motor life and proper cooling, I would use the same fuel as control line guys use.

As far as flying, you may want to carefully consider the "low and slow" philosophy. Too much of that is not good. Usually, with an instructor, you try to keep the plane "three mistakes high."  For example, it is coming towards you and you need to turn left, but your brain isn't hardwired to visualize yourself sitting in the plane yet. And it goes right, so you keep putting more in--more right, because you have not deduced your error yet-- and perhaps even start a spin. But you are high enough to recover if you know how. And you definitely can recover if you can hand the box to an experienced pilot....

Keep having fun!

Dave

Offline Ryan_McFadden

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Re: Engine tuning tips
« Reply #22 on: June 12, 2019, 10:25:42 PM »
All great info guys thanks a bunch. As suggested I did get a Sim; I see where the left is right thing comes into play as well as having some altitude. I plan on using the sim for a bit before I try to fly my plane; Too much time and money in it to crash my first time up. 


Tags: Engine tunning