I have never heard of this "soaking in fuel" thing. All that would do is waste fuel and make the engine wet! Search out Norvel break in on the forum. You need the practice at this. There has been much written about these engines, in addition to what the instructions tell you. These engines use a ceramic cylinder and aluminum piston and are set up super tight. SIG was the distributor for these for a while in their early days, and we stocked them at the hobby shop I worked at part time. We eventually stopped carrying them because people were always returning them as defective. There had never been any engines like that in the general market, so your average Joe had no idea that they really were supposed to be that tight, and people  didn't believe that and would not read the instructions on how to handle them. Once they are run in and fitted well, they will last forever. SIG eventually dropped the, and the line of ARF C'L models that used the .061 in them. They donated the remaining inventory to KidVenture and we used up  the airframes over a couple of seasons of AirVenture activities, but the engines soldiered on in the ToughBaby airplanes that we developed to replace them. Some of those engines had countless hours and run ins with terra firma and still ran well. They have their peculiarities like most engines but you get over them quickly after seeing how they run and the power they make. I know you have an interest in engines in general, but maybe you shouldn't jump around from engine to engine so quickly. You gain more experience and have less frustration. What works with one brand of engine could be death to another. And keeping some sort of note book on what you learn and discover will be helpful also, if you can't remember details very well.
   HAPPY HOLIDAYS!!
   Dan McEntee

Read Ken Cooks Reply at the bottom of this thread:
https://stunthanger.com/smf/engine-set-up-tips/longevity-of-norvel-ame-engines/msg188392/#msg188392

Some more of Ken's wisdom:
https://stunthanger.com/smf/12-a-building/which-has-more-guts/msg180410/#msg180410

In a Norvel break in thread Alan Hahn said this:
"The Norvel 049 likes a small prop load. My favorite prop, before they disappeared was the Tornado Black Magnum 5-3 cut down to ~4.75" diameter. Mine use to scream (>22krpm) on that combo and it pulled my Baby FLite Streaks and Clowns just fine on 42 foot 008 lines. I wouldn't recommend shorter lines unless you like to turn around a lot!

Yes breaking them in is a bear. The small props have almost no flywheel effect, and I am a believer in Norvel delivering "over-tight" piston/cylinder" assemblies because at least then they would have a good fit when (or if!) they were broken in. It would be tougher to have the factory QC the fit to be "just right" with a little pinch on the top. But for less than $30 (with the tank), how could you beat that deal. Before I made my half A starter, I used the Big Mig spring starter as a breakin method. Beat tryin to flip to a start."

My Friend Rusty wrote this here and over on CEF. I wanted to find it just to save typing....


The following is what I have learned about Norvel engines from people who have flown them for decades and whom I consider to be top notch engine tuners, who strongly keep longevity in mind. I have had great success following these procedures, though they do vary from NV Engines publications. I won’t repeat their methods here, but I do believe they are written for people who are not necessarily familiar with performance engines and find the startup to be extremely frustrating. Their method will get it going more easily, but, I believe, at the expense of premature wear. Read their information and consider it before you follow my advice. I’m an amateur modeler and cannot back up my methods with any sort of research. Please proceed after your own consideration of all options.

Read all of the tabs on the following page at NVEngines.com
http://www.nvengines.com/index.php?option=com_content&view=category&layout=blog&id=45&Itemid=18

Now, here is my method:
Once it's mounted in the test stand, leave the muffler off if you have one. These engines have a tight pinch at TDC between the piston and cylinder wall that makes it difficult to start the first few times. Try to resist flipping it over cold before you run it, as this unnecessarily wears the tight fitting P/C.

Since your AME is meant to run on pressure, if you start it up on suction only, mount your fuel tank with the feed line as short as possible and the internal pickup opening of the tank at least as high as the spraybar of the venturi. You can go higher, but beware of flooding, and you might want to clamp the line when not actually cranking to prevent gravity feeding the engine and flooding it. They are not friendly when flooded and can even bend a connecting rod if you try too vigorously. Do not use an electric starter, for this reason. A spring starter can be a big help. Anywhere from 15% to 25% nitromethane will make it happy. I currently use Sig Champion 25, and an extra dollop of castor in the jug is fine if you have some. Never use less than half castor in a castor/synthetic blend, and no less than 20% total oil. If you have any castor-only fuel, I would recommend that, but don’t sweat it if you don’t have any. That’s only my own personal opinion. Make sure the fuel line is full of fuel and ready to go, clamp it off  if necessary, but don’t connect it to the engine yet. Have the glow driver turned on and ready as well.

To make it easier to flip start, especially with no spring starter, it helps to reduce the compression by adding a couple of extra head gaskets. If you have any Cox copper gaskets, they will fit too.  In fact I got frustrated flipping my first Norvel and put a low compression Cox Babe Bee head on it and finally got it started, and ran it that way for one run. Since then, I know a better way, and if you follow the following instructions, the Norvel head will do fine.

The combustion heat causes metals of the piston and cylinder to expand from their cold state to form a perfect fit and let the piston move freely without the hard pinch. So to help that process along, heat the cylinder good and hot with a heat gun. This naturally relieves the pinch, making it easier to spin. Once hot, immediately connect the fuel line. Prime the venturi and give it a few brisk flips, then put a couple of drops in the exhaust. Connect the glow driver and give it a rip. Sometimes back flipping is easier, especially if you’re right handed. Either direction will fire it off. If you see it running backwards it’s just burning off a flood. It might straighten out and kick off. If it’s flooded badly, clamp the line and flip till you burn off the flood.

Once it’s running, find the needle setting for a wet 2 cycle, then turn it on up to full speed. This engine needs heat and speed. The P/C needs immediate heat to fit up properly. Once it warms up, back it down and go back and forth between a brief wet 2 cycle and peak full speed for an ounce or so. Do NOT run it sloppy rich as this will not maintain the necessary heat to keep the pinch loose and will cause excessive wear. After an ounce, clamp it off and let it cool. Do this for several ounces, going back and forth from a brief wet 2 cycle for cooling, to a screaming peak, stopping and cooling completely after each ounce. When it will hold peak indefinitely without heating up and slowing it's ready to go. You can now go back to normal compression if you previously reduced it.

It may not be fast at first, but it will keep breaking in as you fly it until it's really an all out screamer. I also think the 6x3 prop recommended by NV Engines is too much for it(possibly another dumbed down idea for easy cranking). This engine is meant to run higher RPMs than a 6x3 will allow. I would use at most a 5.5x3 for the first run, or even less. If you use APC props, a 6x2 will get it up there, but most others need to be shorter. Remember, the AME needs high RPMs to draw fuel, and will need pressure for flying. A bladder is my preferred fuel supply.

I have 3 Big Migs, and one AME. Once they start really breaking in it will turn a 5x3 prop about 23-24k RPM. I have three Big Migs that are now fully run-in after flying and they will all turn a Master Airscrew GF 5x3 at around 25-26k. But it takes a lot of running to get there. Like I said, as you fly, it will continue to break in. My oldest Big Mig will spin an APC 5x2.5 at 28.8kRPMs. Your AME should blow its doors off. In fact, on my one little AME powered combat plane, I use an APC under 5" long with a 3" pitch

One thing I like to change right away is the prop screw. The supplied screw does not reach very far into the crankshaft. I like screws that go in deep, so I use replacement Black oxide hex head screws that are 3mm x 25mm. I also prefer the ones with an un-threaded shoulder as it fits the Norvel spinner better.

Have fun and come back and let us know how it goes.
Rusty
« Last Edit: September 12, 2017, 02:44:02 AM by RknRusty »


MY last comment is simply that Sig was receiving way too many returns as NOT ABLE TO START...so Norvel changed the instructions to include :
1.      Ensure your engine has the right compression for the fuel and propeller being used (see the article “Get the compression right”)

2.      Always break in cold first - remove the head and a glow plug, inject no more than 1/4 teaspoon of oil into the intake and the same to the cylinder  and spin the crankshaft with a starter for one or two minutes.

YES this works BUT at the expense of unnecessary wear on the engine IMO

3.      Use the proper oil mixture. Requirements - minimum 18-22% oil in the fuel with 

      50% being Castor oil in engines smaller than .15 and at least 25% castor in larger

      motors. If mixing fuel yourself, allow it to settle for a week before use.

4.    Do not operate the engine at 100%. When reaching maximum RPM, enrich the mixture by

       turning the needle valve counter clockwise 2-3 clicks or 300 to 400 rpm less  than peak.

5.      When in flight, operate the throttle smoothly without rapid acceleration/deceleration to avoid a

       hydrodynamic ram on the connecting rod.   

 Guy's
 I sure do thank y'all for advice, and I have a couple of questions, I might have missed them in the advice column, what nitro content with about 22% oil 11 & 11, and what needle to get it to start?  (how many turns out)..   Mucho Grases...       

All of which just illustrates what a miracle Cox managed almost 70 years ago - no fitting, no grinding it out with a starter, no break-in to speak of, and produced by the million.

    Any engine that you have to take apart before you run it is defective.

     Brett