Re: Cranking and running Norvel engines

andrew Tue Jul 31, 2012 9:16 am

Rusty -

Your engine is indeed a Big Mig RevLite. On the C/L versions, the needle is swept back; the AME needle was parallel with the propellor plane. Yours is an earlier model indicated by the turned thrust washer; later models had a cast thrust washer. The other indicator is the rounded back muffler spring. Toward the end of the Big Mig production, the spring was square backed and fitted to the case just below the bottom fin of the cylinder. The case had a small bosses cast into the front and back to keep the retainer spring from sliding down. You can see the boss just below the spring wire on the back of the case. Most of the NORVELs had a steel washer located between the thrust washer and the nose of the case. On occasion, these may be missing on used engines and should be replaced if you ever want to use an electric starter.

Cranking and running Norvel engines - Page 2 Norvel12

**RknRusty** Tue Jul 31, 2012 9:51 am

You guys are giving me some good information. I browsed the FAQ, but that was before I had any first hand trial and error. I'll peruse it again, thanks for the link.

shawn cook wrote:Hard back flips on the prop generally will get you going if standard ccw flips aren't working.

Norvel had some different versions of plugs. One was a 1.5 volt while the other was a 2 volt. Make sure the plug is glowing brightly as these do require a good battery.

I have a prerequisite of items that I follow when running in a new Norvel. Taking the engine entirely apart is one of them. Polishing the crank the same way you do a Cox crank is in order as well. Ken

Ken, that was a lot of useful information packed into your post.
I tried a couple of back flips. If necessary I'll try it again. Standard CCW flips I hope are from looking at the prop from the front of the engine. If I hadn't gotten it to run for2 seconds, I'd worry I had been flipping in the wrong direction. The prop turns CW from the pilot's seat, right?

My plug is almost identical to the medium heat drop-in plugs Bernie sells. They appear completely interchangeable and the one that came in my engine glows very brightly. I've replaced good batteries with new batteries just to be sure.

Funny, I would never run a new Cox without inspecting its innards. I'll take a closer look at the Norvel. I'm pretty sure part of my problem is that I left too much of the pre-run castor in it that I had slathered it with when I was loosening the pinch.

andrew wrote:Your engine is indeed a Big Mig RevLite. On the C/L versions, the needle is swept back; the AME needle was parallel with the propellor plane. Yours is an earlier model indicated by the turned thrust washer; later models had a cast thrust washer.

Toward the end of the Big Mig production, the spring was square backed and fitted to the case just below the bottom fin of the cylinder

Most of the NORVELs had a steel washer located between the thrust washer and the nose of the case. On occasion, these may be missing on used engines

So, you're saying mine looks like a new old stock Norvel, rather than one of the newer NV knockoffs?
Mine does have a thrust washer and I ordered a new one from NV as well as a starter spring and some prop screws. My prop screw may not be the original, as it's fully threaded and difficult to sufficiently tighten. I'm afraid of breaking it, but it's holding now, so it stays until I get my new ones. The reason I have a 6x3 prop is because that's what the NV startup manual said to use.

PV Pilot Tue Jul 31, 2012 10:25 am

I flushed mine as well before running in. Alot of grey dust just from the internals and inside of the case laying in the bottom of the jar when I finished. I did NOT like the factory supplied prop screws, they felt very soft when getting them tight. Maybe it was that soft spinner compressing or ?, but it just didnt feel very good. I replaced them with a grade 10 black oxide button head that I already had and put a dab of Vibra Tite reusable thread locker on the threads when installing. (Vibra Tite is a vibration absorbing threadlocker)

Ken Cook Tue Jul 31, 2012 11:05 am

I'm sure I'll be flamed for this. I break in with extremely small light loading props. A 6x3 in my opinion is large. In fact I would say that would be the largest prop for this size engine. Everyone else will have mixed opinions on this. These engines are packed in Cosmoline, therefore the engines really need to be flushed and Norvel recommended the use of gasoline for doing so. This was to be done prior to the oil soaking treatment. I for one run these engines for combat although I have a few Big Mig's on stunt ships. I'm running 2 pitch props on stunt. On combat, I'm trimming the Cox rubber ducky to 4 1/4" and smaller. I try and get the rpm's up quickly without a load and shut down and cool. But that's me. Flipping a small prop is a pain in the a$$ though. I can use a bit more pitch on the .061 due to the larger displacement and I've used the 4.5 x 3.5 successfully as well. For the larger props, I really like the 5.5 x 2 or the 5.5 x 2.5. If your using a 6 x 3 and it's a Cox prop, your dealing with a lot of blade area on that prop. A APC 5.7 x 3 would have less load.

On another note, I discovered this earlier today. I'm assuming the spray bar hole on the bolt on venturi model is the same as the epoxied in model. I would bet the farm on it. That being said, A Cox fine threaded needle assembly from the red backplate will work. I discovered that you can take 5/32 K&S tubing cut it to the width of the venturi to bush the hole. I roll it under a knife blade and you can cut some real accurate small slices. You need to drill a hole centered in the tubing, I drill 3/32". Insert the Cox spraybar into the 5/32 tubing aligning the hole in the spraybar with the 3/332" drill hole and solder both ends cleaning all flux etc. Prior to soldering I cleaned the spray bar extremely well on both ends with the exception of the hole area so that no solder would find it's way into it. You can then chuck the assembly lightly into a cordless or drill press scarifying the outer diam of tubing with some coarse sandpaper. I then epoxied the assembly into the aluminum venturi body aligning the spraybar hole with the venturi opening. Your all set for bladder now. I always mention this : cut down the needle so it's not above your fuse when mounted on the plane so it doesn't break upon landings. Ken

andrew Tue Jul 31, 2012 11:25 am

RknRusty wrote:So, you're saying mine looks like a new old stock Norvel, rather than one of the newer NV knockoffs?
.......... My prop screw may not be the original, as it's fully threaded and difficult to sufficiently tighten. I'm afraid of breaking it, but it's holding now, so it stays until I get my new ones. The reason I have a 6x3 prop is because that's what the NV startup manual said to use.

I've never seen a round head prop screw on any of the Revlite series engines -- all have been slotted hex-head screws with a partial shank and they are fairly hard.

NV is not really a knockoff. When the Soviet Union began to break up, many military production facilities started to search for possible markets to support their workers and keep their plants open. NORVEL already had a following in the C/L combat community with their Northern Velocity engines. George (GCB) has one of the early models, a ZEUS, I believe. NORVEL was founded by Ed Stevens, an American who had worked for the Russian military complex after the cold war. He set up the distributorship for the NORVEL brand and later sold it off to SIG. The plant that had been producing the NORVEL line moved on to more lucrative contracts and terminated production. The NV consortia purchased the equipment from the original company and is being run as a stand alone manufacturing operation. So unlike the Chinese knockoff, the AP Wasp, the NV line is being produced in Eastern Europe by the same group of folks.

The early AAN engines used a different plug, one that was colder and took as much as 2v to start well. It was replaced with the "Freedom Plug" that is different sized, hotter and will ignite on 1.2 - 1.5v. Your engine uses this plug.

The 6x3 is OK for breakin; a 6x2 would be better -- I prefer the slightly larger prop to help provide the rotational inertia to keep the engine running until it loosens up.

Edit: I certainly wouldn't flame Ken for his choice of break-in props -- he has spent a lot of time with these engines and obviously knows his stuff. Some of the NORVELs can really be aggrevating when first starting. I hand flip only and have not had very good luck with smaller props initially, at least until I can get short runs. As the engine begins to run better, I'll back off on the prop size. A 6x3 is really too large for the NORVEL when flying (I have used them if I had nothing left in the field box) -- the APC 5.7x3 is probably the largest that should be used. I think it runs well because the blades are thinner, more narrow and the tip mass is very low as opposed to the MA and COX props. For paddle bladed props (COX and MA), I like the COX rubber ducky 5x3 or the MA 6x3 cut back.

Ken Cook Tue Jul 31, 2012 12:55 pm

I'd like to thank you Andrew for that compliment . Andrew, your spot on with your small to long prop concerns as one has more momentum. This is why I stated that flipping a small prop is a real pain. One thing for certain, this forum has some knowledgeable members. I for one am only control line orientated. I know nothing of r/c. If the larger props work for R/C then I do apologize for my statements. Control line guys are running the engines flat out for minutes straight while this more than likely wouldn't be the case with R/C. Rusty, the problems you've encountered have been faced by all of us who made the transition from Cox engines to modern ABN, ABC, AAC engines. Back when these were being introduced, they didn't have a website just a basic flyer installed within the box. I received my engines from Norvel directly without a box or instructions They made engines available with boxes that were mislabeled and also damaged or without instructions for a real bargain for under $30.00. This is when Cox was really struggling and I think this certainly may have been the demise of Cox.

Several people who purchased these engines were starting to get a bit heated due to the problems we all faced and like I said, not all of us even had engines that came with instructions. I had written many e-mails to them indicating certain problems that we were being faced with.Some of these I listed above about the o-ring for example. The plug issue although has been resolved long ago was another issue. I didn't know that I knew so many cuss words during my initial experience with them. Norvel then placed a troubleshooting memo on their website explaining from A-Z. The website is now defunct. Seeing some of those examples of how and what to do next on the troubleshooting guide came from the testimony of several flyers I know who wrote to them complaining of the problems we were experiencing. All I can say, were very fortunate to have NV engines once again available and parts as well. For those in need of parts, Alex from NV engines is a reliable person to deal with. Ken

**RknRusty** Tue Jul 31, 2012 1:32 pm

This is getting to be a very entertaining read. Very Happy

I have a lot of information to work with now. I've been occupied with much less fun details all day, but before the day ends, the engine gets a tear-down and cleaning. I have to drain my lawnmower tank to change the blade(next on the list), so I'll have some gasoline for that. I'll oil it, mount it, heat it up and give it a spin. It will run.

PV Pilot Tue Jul 31, 2012 1:44 pm

lol, I had ordered a .049 piston and sleeve from them back in April and didn't realize it hadn't been shipped to me until this thread came up. Thanks Rusty,, Laughing

Just emailed Alex and one is on the way soon. He had forgot about it also as we were waiting for some other parts to come in.

Just a tip, if you do order parts from them, email them a list first to check on stock levels, as the checkout didn't show those levels at the time I ordered my piston/sleeve. (which was on backorder and I got charged for it back then)

andrew Tue Jul 31, 2012 1:55 pm

shawn cook wrote: Control line guys are running the engines flat out for minutes straight while this more than likely wouldn't be the case with R/C. ...................

The AME model will throttle OK, but most folks flying this engine as RC are interested in all out speed and not puttering around, consequently, it's mostly WOT. The Big Migs throttle better, but prop diameters in the 5" to 5.7" seem to work better than those under 5".

All NORVELs are ported to turn higher RPMs, so lugging them with too much prop does not let the engine get up into it's designed power band. The only downside associated with really small props is stalling. With C/L, you have the option to whip the plane until it starts flying; for R/C, it can take quite a heave to get enough speed to keep the plane in the air until the prop hooks up --- but, when it does Very Happy

.

Norvel then placed a troubleshooting memo on their website explaining from A-Z. The website is now defunct.

These pages have been reproduced in the RCU NORVEL FAQ starting on page 14 of the thread. They were captured before the NORVEL site was terminated -- it's text, but all the information is there.

**RknRusty** Tue Jul 31, 2012 5:09 pm

I took it all apart today, and Eeeew. It's no wonder it wouldn't keep running. Every time it sounded like it was lit, it put its own fire out. The crankcase was full of black and oily liquid and smelled like fuel. So, partly my flooding and partly my having left too much castor in it from step 1. I don't know where all the blackness came from, but there was a tiny flake of something that looked like plastic film. I also know where to set the intake valve if I need to shake out a flooded crankcase. If it had started, it could have possibly hydro-locked. I'm glad I escaped that peril. Live and learn.

After a thorough cleaning it still looks like it's never been run before, no wear on the crank at all. The piston isn't as chrome-shiney as a cox, but no scratches. It's all good, now I know what all is in there and how it goes back together. I want to replace the sleeve screws with some long enough to protrude from the bottom in case I ever bust a head off of one of them. And yes, I put the gasket back in correctly. All I have left to do is inspect the venturi assembly and screw it back on.

One question: what keeps the wrist pin from sliding over and galling the sleeve wall?

After supper, I'll go finish it up and crank it.

gcb Tue Jul 31, 2012 5:34 pm

RknRusty wrote:...The piston isn't as chrome-shiney as a cox, but no scratches.

Perhaps that's because the Cox piston is steel and the NV one is high-silicon aluminum. Cool

George

OK Sorry for being a Smarta**! Just couldn't resist.

Props...for the .061, many folks prefer an APC 5.7x3 or 6x2...unless you are flying combat. I vote with the folks who say 6x3 until it is broken in. When in a plane, don't over prop it. Fuel draw will suffer.

Good luck with it. You will like it a lot better after it has a few runs on it.

Godsey3.0 Tue Jul 31, 2012 5:55 pm

Does the wrist pin not have a clip? I noticed this on my father's McCoy and my K & B Torpedo. I was afraid I had lost something but was sure that I did not.

Rolla

**RknRusty** Tue Jul 31, 2012 6:09 pm

No clip. I can take a toothpick and push it too far out of the side of the piston. I suppose it'll stay. A hundred fifty million Russians can't be wrong lol!

Ken Cook Tue Jul 31, 2012 6:28 pm

Rusty, something doesn't sound correct there. I know for a fact one side is staked. I thought the other side had a circlip. I could also be thinking of my AP engine which I recently had apart. I believe the wrist pin is in line with the crank from front to back. They're are no cylinder porting cutouts in that direction. I don't know that area of the engine that well due to the fact that I don't like to play with those small circlips if it has them. Working inside a sandwich bag is your best bet if you have to remove circlips or install them. I just don't ever remember a wrist pin ever sliding out and I've taken a few engines apart that really ate some dirt. Swishing the parts in a custard dish with alcohol, I don't recall the pin sliding out, although that really doesn't mean anything. I do know some of the exploded parts drawings with the instructions show this. Do you have instructions? I can look myself downstairs as well. Ken

Ken Cook Tue Jul 31, 2012 6:43 pm

I went downstairs and located a new in the box Big Mig .061 with instructions. They show no circlip on the wrist pin. My AP does however have a circlip to hold it in. Norvel lists the rod, wrist pin and piston under one assembly. They don't give a breakdown of parts. It just lists piston and the category number. Ken

fit90 Tue Jul 31, 2012 6:45 pm

Norvel .061 Big Mig Revlite parts manual shows NO circlip, only a wrist pin, piston and connecting rod. It seems to be this way with the Revlite and pre-Revlite AME's and Big Migs.

**RknRusty** Tue Jul 31, 2012 7:52 pm

Same here, I just checked my exploded view. I guess we'll find out soon.

Godsey3.0 Tue Jul 31, 2012 8:26 pm

The sleeve on my Torpedo shows a very faint mark where the wrist pin sits. I am not sure about the McCoy. I do not really want to open it up again. I worry about messing it up.

Rolla

fit90 Tue Jul 31, 2012 8:33 pm

Rusty,

Did you get a chance to try starting it again?

**RknRusty** Tue Jul 31, 2012 8:38 pm

No, I'm finally free to head out to the shop after I post this. I just have to put the venturi back on and it'll be ready to mount. If I don't fire it up tonight, I'll be ready to flip it off tomorrow afternoon. If I crank it tonight, you can bet I'll be back to tell you about it.

Okay, goodbye for an hour or two.

microflitedude Tue Jul 31, 2012 8:41 pm

RknRusty wrote:No, I'm finally free to head out to the shop after I post this. I just have to put the venturi back on and it'll be ready to mount. If I don't fire it up tonight, I'll be ready to flip it off tomorrow afternoon. If I crank it tonight, you can bet I'll be back to tell you about it.

Okay, goodbye for an hour or two.

At this hour? Shocked

Ken Cook Tue Jul 31, 2012 8:42 pm

Rusty, I highly recommend you either CA the venturi retaining nut to the case or use Loc-Tite as vibrations will make the nut come loose and it will certainly be gone. Ken

fit90 Tue Jul 31, 2012 9:11 pm

RknRusty wrote:No, I'm finally free to head out to the shop after I post this. I just have to put the venturi back on and it'll be ready to mount. If I don't fire it up tonight, I'll be ready to flip it off tomorrow afternoon. If I crank it tonight, you can bet I'll be back to tell you about it.

Okay, goodbye for an hour or two.

Good luck.

I look forward to reading about it tomorrow morning.

Bob

**RknRusty** Tue Jul 31, 2012 10:42 pm

microflitedude wrote:
RknRusty wrote:No, I'm finally free to head out to the shop after I post this. I just have to put the venturi back on and it'll be ready to mount. If I don't fire it up tonight, I'll be ready to flip it off tomorrow afternoon. If I crank it tonight, you can bet I'll be back to tell you about it.

Okay, goodbye for an hour or two.

At this hour?

It's a rare day when I get shop time during the week before this. On the weekends, sometimes I get some afternoon time. I might get some time between 3 and 5 tomorrow afternoon, and more tomorrow night.

I made a movie of it tonight. I can't feel any hard resistance at TDC any more except when it's obviously flooded. Ken's advice to whap it backwards works ten times better and I made a good chicken stick. At various needle settings it would crank and run really fast for about 2-4 seconds. I would richen the needle an 8th of a turn every time it Braaapped fast for 4 times in a row, until I reached a point where there was nothing again. So I'd pinch it off and burn off the flood and start over again. That went on for an hour and a half. The fuel tank and line at the nipple is at a height where it's right on the edge of where won't gravity feed into the engine. maybe I should lower it and make the engine try harder for it. Sometimes I pinched it until it cranked, but it would cut off as soon as I un-clamped it.

The venturi, spraybar and all orifices are clear. The tiny o-ring around the venturi screw is split, but when I tightened the screw it closed up all the way around and looked like it had a good seal. The main o-ring is still supple and I had to squeeze the venturi on to push it through the hole to put the nut on it.

Tomorrow, I'll open the back and pour off any fuel puddling in there and try again.
Then I have to get ready for surgery on my right hand Thursday, so I'll be taking a break from fighting with it. One way or another I'm going to kick this thing's ass. I don't take crap off of machinery.

andrew Tue Jul 31, 2012 10:52 pm

RknRusty wrote:

One question: what keeps the wrist pin from sliding over and galling the sleeve wall?

After supper, I'll go finish it up and crank it.

The pin should be staked on both ends. Of all the things I like about the NORVEL, this is not one of them. The staking looks as if the piston is placed in a cradle fixture, a wire is placed across the wrist pin hole at 90 degrees to the rod, then swaged with a press.

To replace a rod, the pin has to be driven out, then re-staked. I have never had to do this and I'm not sure of the best way to manage it without a cradle fixture. Unless the piston is fully supported halfway up the side, too much staking pressure could conceivably drive it out of round. It can't have an endpad due to the pin lining up with the intake ports. The AP Wasp knockoff does use a circlip.

Aside from being less expensive to manufacture, NORVEL (NV) may have decided to use staking in place of a clip since the clip could stress fracture after a lot of running at high RPMs. Can't imagine what the end result would be if the clip broke at 25K rpm -- nothing good I suspect.

Waiting for Rusty's report.

andrew

EDIT: Rusty posted while I was typing. Hang in there -- don't let a tiny engine kick butt. I think what you're seeing as a split o-ring on the venturi screw is just a lock washer to keep the screw from backing out.

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