Breaking in Norvels

[Bud Morrison]

The Norvels are nice lil engines once you get past the learning curve and 4 letter words while breaking one in the first time.
If anyone has any suggestions and or break in recommendations or stories please post them here.

[TEM]

I couldn't agree more. I spent about 2 weeks trying to get the .074 big mig rc to run for more than 3 seconds. The prop nut also wants to come out. But I'm feeling mines a dud(or badly assembled at the factory anyways). The engine turns over real tight like it was suppose to. I tried a million things and it won't work. I tried to dissemble it but 1 cylinder screw I couldn't get out, got pissed and starter trying to rip the engine apart with my bare hands(won't apart ofcourse). Then I put it together, and it turned over with "normal" tightness(ie, an OS FP10 kinda feel). After that it starts alright and runs with power! I looked on Davis Diesel's site and they had conversion for .061 and .049 norvel. Didn't see it on the price list but I could have just missed it though.

[Bud Morrison]

No that's how the Norvels are when they are new. Some are a lil tighter than others but all are usually tight enough that if you don't have the prop nut torqued up good they will come out.

What I do to avoid this is to put a lil after run oil in. Warm the head and cylinder up with a heat gun. You will notice once warmed up it will turn over allot easier. Then I start the engine and run it just past the 4 cycle stage. I also break in with a prop one pitch higher than what I am planning to fly it on. This is just my preference and not really necessary. You want it to run at temperature. Running it to cold is not good. On the same token running it to hot or lean is not good either. I run around 4 tanks through like this and the motors then seam to loosen up enough to be started without the preheat.

[RiBell]

Sometrhing else I've heard. And I don't remember if I did it or not is to put all three head gaskets in to lower the compresion
Rick

[Bubbafly]

I have had a lot of norvels, and I am no expert, but I subscribe to the motocross bike method of breaking in two-stroke motors. I start with a little after run oil in the cylinder and turn it over by hand like the norvel manual says. Then I start it and needle it rich for about two minutes.( no I don't run a few tankfuls through it). I let it cool down, fuel it up, start it, needle it like I am going to fly, then fly it!! During that flight I vary the throttle position a lot. After that flight( tank ) I fly as normal. I learned this during my two boy's motocross days, and we never blew a motor or had a motor that didn't run well. Just my opinion.

Bubbafly:D

[TEM]

Yes, I understand what you guys are saying. But what puzzled me was the dissembly process solved my problem by presenting me with another one. There is 1 head screw I could not take off. And after trying to rip the engine apart with my hands and reassembing the engine together again loosed it up! and it finally ran alright.....

My OS engines were real easy to work with, and the Cox ones are right after it. Actually, currently my cox engine(1 left) starts the easiest! Fill tank with syringe, put a drop in the exhaust port, clip on glow wire, and touch with a homemade starter. Takes like a minute including filling the tank!

Anyways, back to the norvel. After my complete dissembly, I noticed the carb is kind of loose(rocks back and forth just a tiny bit). But the engine runs fine(though I haven't tested with a tach nor do I have one). Am I missing a washer or seal? Or have any of you experienced this?

[Bud Morrison]

There should be an oring that goes between the carb and the engine. I have also used a lil silicon on mine when they quite didnt fit tight for some reason or another.

[1705493]

The Norvel Revlites are unlike any engine you've ever had before. They use a hard anodized cylinder which is basically aluminum oxide,,, the same thing as sandpaper. Very tough. The piston is nickel plated. Instead of a soft/hard combo you get hard/super hard. I believe it's Norvel's intention to, one, make the fit very tight, second, the abrasive nature allows the nickle piston to be worn in to a just right fit,,,, at temperature.

I like the heat gun method. Using oil to lube up the cylinder can work also. What's happening is that the anodize is porous and the oil loads the pores and helps. The downside to that method though, is that if you overprime and raw fuel spashes excessivley in the combustion chamber, you can wash out the lube and the engine might then lock up pretty hard. I've had this happen to me on a well run Norvel.

I also agree with the break-in in the air with regular throttling up and down to heat cycle all the parts.

Either way, don't be sad or mad if your Norvel is %$#&* tight at the top. They just need to be handled differently.

[Bud Morrison]

Originally posted by 1705493
I also agree with the break-in in the air with regular throttling up and down to heat cycle all the parts.

Either way, don't be sad or mad if your Norvel is %$#&* tight at the top. They just need to be handled differently.

Hey its nice to see you here :) Now maybe you could let us in on the secret of you needle valve mod hehe. They are awsome! You could prolly dedicate a whole thread to it and other mods.

[1705493]

The secret is actually a combination of things, most importantly a means of adjusting the mixture at idle. As it turns out, complex, two needle throttles are not really necessary. I've got Coxs, VAs and Norvels, throttling virtually perfectly. There are a number of elements within the engine that need to be in place allowing just a simple, adjustable air bleed carb to work properly.

All the traditional excuses for poor throttling in small engines are no longer valid.

Just to clarify a point on my previous post. When talking Norvels, it's important to differentiate between the early AAN series with the silvery fins and the newer Revlites with the dark grey fins. The early AAN were a traditional nickle plated cylinder with aluminum piston. These could be handled in the usual manner that we've all become accustomed to.

The Revlites, are a different beast. And beast they can be if you don't know what makes them different. They are a brilliant piece of innovative engineering that gives the best power to weight ratio of any engine ever seen.

The Revlite .074 is especially unique. I own two and have handled two others. Right out of the box, this engine throttles perfectly. It does have a bolt on sealed muffler and amazingly, it has no adjustable airbleed. Like the OS .10 it does just fine with just the main, high speed needle. The key to making the .074 work is to understand that the high speed needle can control both the high and low end.

The best way to adjust for the perfect needle setting on this engine is to do it in the air. Here's what I do. On the ground, with the nose up, adjust till you just lose your four cycle. If you dial in the needle beyond this, you will find that it has a very broad range without apprecialbly affecting the mixture. How this happens (in this particular engine) is under investigation. In any case, if it holds the idle, you're half way there but you've got a bit more to do. Holding the idle is good but what's better is perfect transition and instant power with no smoke or hesitation. Take off, fly to a good height, throttle back and cruise down to eye level. Crack the throttle open and you'll likely get smoke and ragged acceleration. Not to worry. Land, taxi back and tweak the high speed needle an eighth of a turn lean. Go up again and try the same maneouver. It'll likely take you a few tries but once set, you can virtually forget it except for tweaking a bit back and forth if you change fuels or there's a radical change in temperature, pressure or humidity. The result is an engine that gives superior power to weight ratio, is affordable, has excellent quality second to none and throttles virtually perfectly to boot. The new standard in small engines as far as I'm concerned.

Again, why this is so is a mystery actively being investigated. The .06 and .049 series, I'm afraid, are not the same animal. The air bleed needs to be made adjustable. A sealed muffler, though not absolutely necessary, does make a contribution. The current series won't idle below 8K and this can be a problem with some aircraft if you want to land under power. The solution is simple and easy to do. But, that's going to be a secret for now.

;)

[goldguy]

I have broken in 8 Norvels, 6 .061's and 2 .074, nary a problem. I have told others of the method and they too have been successful. This well known secret.......... the heat gun!

fly SMALL, have a BALL.........Frank

[Lynn S]

I just ordered a Norvel Big Mig .25 for my Tequila Sunrise.
My question is....do you break-in this engine any differently than a .074?
I have one of those and have learned that it runs better with 20% castor oil mix. It was easy to lock up if it was adjusted a little too lean before I started using the 20% mix. The last time I ran that engine it ran like it had a pipe on it.
Do I need to run 1/2 A fuel in the .25 also?

thanks, Lynn

[1705493]

Lynn,

The only other Revlite I've owned, was a .15 but it was already well run in so I don't know if it's any different from the .06 as far as breaking in is concerned. That being said, it couldn't hurt to use the heat gun method. No harm would be done and you'd avoid all that stress on the parts while trying to strong arm the engine over. It may work with oil in the cylinder but as soon as the prime hits it, the oil might get washed out and things gert real tight again.

I highly approve of an all castor mix. Still the absolute best oil for our engines. Hard to get sometimes so I try and use a blend but add enough castor to take it to 22% or so.

Let us know how things work out.

[Lynn S]

Andy,
I just got the new engine in today. The instructions are the same as for the .074.
Tell me again how the heat gun method works... also I have sent you an email.

Thanks, Lynn

[1705493]

The Norvel Revlites, like other AAN/ABC engines are set up very tight at TDC on purpose. The idea is that the cylinder will expand just a bit more than the piston and at running temperatures, the fit gets to be about perfect. Manufacturing tolerance will have some engines tighter than others and a proper run in is required.

This style of engine, unlike the old iron piston deal, needs NOT a lot of break in. Just a light run in at a just lean setting. NEVER slobbering rich. If you run rich for any length of time, the parts will not come up to temp, not expand properly and will wear out prematurely.

AAN and ABC engines use a plating on the cylinder and the piston is high silicon aluminum. This gives you a hard/very hard combination. Old technology used a hard/soft combo so the hard/very hard is an improvement. The Revlites go one better and give you a very hard/extremely hard combo. The cylinder is hard anodized, a form of aluminum oxide and this is hard, second only to diamonds, I'm told. The piston is nickel plated.

Some sandpapers are actually aluminum oxide and this means it's quite abrasive. The Revlites get away with this because in addition to being hard, the finish is also porous. This means it retains oil unlike AAN/ABC. The oil however can fool you. Soaking in oil will certainly make things all slippery and the prop will flip over OK. But, just get a bit too much prime into the engine, and if it hits the combustion chamber enough, it can wash out your oil and the engine can lock up. This has happened to me several times. The only way to free it up safely, is NOT to strong arm it though, but to use a heat gun. The heat will expand the cylinder more than the piston and will free up the engine.

Avoid the risk of a lock up and use the heat gun at the very outset. Just blow that hot air over the cylinder for two minutes or so, prime at the intake and flip or hit the starter. You will have opened the needle to where the instructions say and once the engine fires and runs, quickly dial in the needle until it goes JUST lean. Don't peak it out, just take it in till you just lose the four cycle. I let it run this way for one or two minutes, shut it down, let it cool off and repeat the process a half dozen times or so.

At this point, you can dial the needle in a bit and increase the run times to five minutes at a time. For the .06 and .074, I'd accumulate about a half hour total run time on the bench. Then, in the plane, I'd be sure to throttle up and down a good number of times, checking throttle response and heat cycling the engine for the first few flights.

After that, your Norvel should give you good service and long life.

My .15 has many dozens of flights and hot or cold, it still has that nice snap over when flipping the prop. As do most of my .06s.

[Lynn S]

Andy,
Do you use the heat gun every time you start the engine until it is broken in?
Thanks for the good info on the engine. Now I know what expands.
Lynn

[1705493]

Lynn,

Yes, all starts on the bench will get the heat gun treatment. Note that this is just the initial running in,, not break in. Full break in will be done in the air. In which case you can't use the heat gun,,, unless you've got a really, really long extension cord. ;^) Once you have about a half hour on the bench, the initial super tightness will have been freed up somewhat allowing you to more easily start the engine in the field.

If the .25 is anything like my .15, .074s and .06s, I think you'll be most happy with your .25.

[thomer]

Hey guys,

Been reading this thread, and wanted to share my experience w/ my AP Wasp .061 which I have heard is a Chinese knock-off of the Norvel .061.

I started breaking it in the other day using 25% nitro & 20% castor (what AP recommends) and it would start running for about 10 to 15 seconds, then shut off. Air bubbles were hitting the carb.

Kept trying to get it to kick over, then the engine would flood. Then it would start and run another 10 to 15 seconds and shut off. Then, trying to start it, no gas was reaching the carb, only air bubbles. Then gas would flood the engine again after 15 to 20 seconds of trying to start it again.

This happened for many more cycles, then began the de-bugging trials. Checked the fuel tank, tighened screws, checked glow-plug, re-checked, etc.

Same thing kept happening. Then I took out the needle valve out, and looked inside of the hole. On one side, it had the proper size hole, but on the other, it looked to be obstructed. It only had 1/4 of the opening the other side had. So I took it, blew it (I know...not the best way) and the hole was now the correct size.

I have not had a chance to restart it since then, but do you guys think this was the problem?

Thanks!

thomer

[goldguy]

The AP Wasp .061 is the older non Revelite model made by AME in Russia. Still running a few of those older ones and can't wear them out!

Air bubbles to the carb........ check the plumping including inside the tank, even split at the clunk will give you grief.

[thomer]

The engine must have had a leak somewhere. No matter what I did, it just didn't suck gas.

Took it back to Hobby People today, and they exchanged it for a new one. Threw in on the bench, it fired right up, (well, maybe not "right" up....more like 30 seconds) broke it in for about 20 minutes, and she runs great!

Now going to slap it into my Clancy Lady Bug SPAD! Oh what fun!

thomer