Big Mig 061

[Motorman]

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[Chris Sarnowski]

You could check www.nvengines.com for the engine. They have their own plug and head setup. There are a variety of aftermarket heads/plugs such as the Merlin set up or a Doug Galbreath head. Post or search in the 1/2a section.

[944_Jim]

Motorman...same MM as on CEF?

Regarding the glowplug, I know the Cox .049 glowplugs fit, as do the Merlin glowplugs. I believe using the high compression Cox head will get your Norvel closer to stock compression ratio. ISTR my Norvel output fell off a bit using the Cox standard plug.
Alas, Merlin is no more. I hope they start up again, but I'm also getting to the point in life that I understand what happens to a small business when the patriarch passes.
I thought the ceramic was only on the piston/cylinder? I need to check my stash of Norvels now. I didn't know the earlier Norvels (pre-Revlite) were finished in nickel! I also thought my Revlite NVs were natural aluminum exteriors. Hmmm. Another detail to watch/look for.

[Al Ferraro]

http://www.mecoa.com/acc/glowplug/norvel.htm

[Dan McEntee]

   As far as I know, Norvel engines have always had the same construction, both the original company and the new edition. basically aluminum pistons and ceramic coated cylinders, because you can't use the cylinder as a ground for lighting the glow plug. I had never heard about any Norvel engines with a nickle plated cylinder bore. I had a conversation with Al Kelly here at our speed contest one year about 1/2A glow plugs and such, and he told me that the Cox and Norvel threads do fit, but are NOt the same thread. They are close enough that you can screw a cox head onto a Norvel cylinder and it will turn enough for it to seat. Al was a neat and interesting guy to talk with.
   Type at you later,
   Dan McEntee

[Fredvon4]

some info for folks following:

http://www.nvengines.com/index.php?option=com_content&view=article&id=70&Itemid=54

Our Revlite technology is light years ahead of other engine makers. Current ABC technology is over 40 years old and reached its maximum potential decades ago. Instead of using heavy brass liners, NV cylinders are made from lightweight aluminum and ceramic coated with high silicon content pistons.  Rather than rely on outdated metal-to-metal contact for sealing, NV ceramic coated cylinders hold oil in the small pores in the surface and achieve compression by means of a hydraulic seal. This not only creates better compression, and hence, more power, but eliminates the enemy of all performance motors; friction and heat. This lack of friction combined with our Sliktek™ coating allows  NV engines to rev much higher with far less heat, burn much less fuel, and last far longer than conventional engines.

NOTE:  current .061 for sale
"AMD 061- Pre-Revelite Race Engine. An all-out high rpm 1/2A motor, the AMD .061 CL turns over 23,000 rpm and is best used with a crank case pressure tap"

My understanding is new production of .074 and smaller ceased several years ago and no RevLite any more-- current .061s for sale are new OLD stock until depleted

NOTE the "still for sale" Doug Galbreath Nelson heads are usually $12~$13

Nelson Plugs, are plentiful and usually $5+/-.

The Merlin version are scarce and commanding higher costs. The Merlin Nelson Style plugs had more heat ranges and were produced to use standard tool  1/4 vs 3/8th? (senior moment)

For what it is worth, Dub Jet still has Merlin plugs and a small amount of Nelson plugs that have been machiend for the smaller tool

[Brett Buck]

Where's the best place to buy a Big Mig 061? The ones on eBay are all nickle plated.

   I don't think any of them are nickle plated, unless someone ground off the aluminum oxide and plated it.   Even had they, I doubt it would make a significant difference in the results.

   Note that the passage from Norvel that Fred quotes contains several misleading items - all slug-piston engines rely on the same principle to seal, and none of them run significant metal-to-metal contact, or at least, not for long! There must always be a oil film separating the parts, if you don't, you get the problem in the other thread - turn the engine over slowly, particularly with no glow plug, and the oil gets displaced, you get metal-metal contact, and it sticks hard. Fast, and under compression, and the oil stays in the interface, no problem.

   Same with ringed engines, except that they replace the low pressure an lots of surface area with high pressure and small surface area, the high pressure being the combuston pressure (maybe 400-500 psi) behind the ring forcing it out into contact. Tension-type rings count on some preload to make it work at low RPM during starting, Dykes rings have no tension, and count on the pressure "bell-mouthing" the asymmetrical cross-section so that only the upper edge  supposedly contacts, riding on the corner. Whether and how long this actually works in model engines is highly debatable - most of the good-running Dykes ring stunt engines seem to have equal wear across the entire face of the ring, rather than just the top edge. I always figured they were far too thick in cross-section to actually "bell-mouth" in practice, at least for long.

   Slight metal-metal contact, or debris, is what causes wear. Lots of metal-metal contact = seized. Ceramic helps because the slight contact is no longer metal-metal, and cannot spall off material from on surface to another, which typically causes more contact, more material transferred, then it stops abruptly.

   This is just another type of bearing surface.  Bearing tribology (the study the friction and wear in bearings) is a very complex and arcane subject, and appears to involve black cats and guys in conical hats emblazoned with signs of the Zodiac. All of these different experts tend to disagree on every topic, so, like all legitimate scientific pursuits, you choose which wizard to believe.

    An interesting bit of information for our electric motor pals - it's possible to have wear from micro-arcing across ball bearing surfaces with as little as 3 volts differential between the balls and the races, so better figure out a way to ground the rotor to the stator...

     Brett

[paw080]

Where's the best place to buy a Big Mig 061? The ones on eBay are all nickle plated. Looking for the newer Revlite ceramic version. What does it use for glow plugs? How large of an airplane will it pull 250 Sq in on 52' lines? Do you really need flaps on a plane that small?

Thanks,
Motorman

Hi Motorman, I cannot answer any of your Big Mig 1.0cc questions, But I can tell you that that engine will
pull a model 250-300 sq" quite easily.  I have flown a Sig Akromaster(250 sq"s) powered by an MP-Jet 1.0cc
Diesel engine on 45'  X .008" lines with excellent results.

Use of flaps on any small model is up to you. Flaps will smooth and soften the model's directional changes.
But flaps will not increase maneuverability.  Best of luck,
Tony G 

[dave siegler]

There are 2 kinds of cylinders .  The black revlight and the older silver colored (Nickel patted?)  AME. 

I have ad good luck with both, however the revlight ones may hold up longer.  The earlier ones often came in very tight. 
The older ones have a little shorter cases and for me were strong runners.  They still run them at EAA kidventure and many have many gallons of fuel through them.

They use a head clamp and button type plug, and you can  make a turbo or nelson button easily if you have a lathe.  I don't know the threading but the head clamp and a cox glowplug seem interchangeable. 

A few had tight cranks as well, and would overheat. 

[944_Jim]

Wow!Neat picture. Thanks a bunch. For the first time I see the two engines side by side and realize another tell is the length of the engine. It appears the Reclite has a longer crank/case.

I appreciate learning that detail.
Does it carry through the line? .049/.15 too? Did the .074 come in two generations as well? Is there also an AMx version of the .074?

Thanks in advance!

[dave siegler]

the old style is only for 049 - 061.  thin this is chromed cylinders

[Fredvon4]

Not so fast on case length being a way to tell
NV made a series of AERO combat short nosed cases that might could have either top end installed

Externally there is not much way to tell much about any vintage NV engine IMO 

I wish Ken Cook would climb in He has a lot more to add and a discussion on the Zeus versions will happen

[Dan McEntee]

    I may be wrong but AME engines and Norvel are two different engines completely. Nothing interchanges between them. I would have to check, but the AME engines I have don't have any mention of Norvel in their paperwork. I think they are definitely apples and oranges.

     "So the early ones with the cut outs in the fins are Chrome plated and the later ones are Nikasil hard ceramic. I wonder which one has the better fit."

    Again, here you are talking about apples and oranges. Norvel engines, with the Norvel name on them, have always been made the same by the two different manufactures, as far I I know. It makes no production sense to be constantly changes specs, and materials on relatively low production items. Norvel .049 and .061 engines were always ceramic cylinders, and AME engines are something else entirely. I think AME existed quite a while before Norvel.

  Type at you later,
   Dan McEntee

     Edit to add PS: I have been trying to remember another Russian 1/2A engine that was before AME and Norvel.... Was it VA? Or something similar? The engine case split horizontally at the center line to allow timing adjustments or something> I think the AME engines are closer to those or made by that company>
 

[Mike Anderson]

AME and BigMig are/were two different models of Norvel engine.  The AME is the high performance version, and had a larger venturi, that wouldn't run on suction.  BigMig is/was the sport version set up to run on suction, and with tamed porting and timing.  "Norvel" was a contraction of "Northern Velocity", who took over the  import of them.  At one time Sig was either an importer or a dealer, as they did warranty work and sold parts as well as engines. 

[kenneth cook]

           AME was originally the engine manufacturer, the case had AERO with a backwards E. They produced the Zeus which is what Dave shows in his picture. Later afterwards did AME become the cylinder designation. The cylinder will interchange from a AME Zeus to a Norvel. The rod also works as well as driveplate. Early Norvel engines used the pinch type collet like the AME Zeus but later went with the D hole drive washer. AME Zeus engines were somewhat hit or miss, you either had a good one or a bad one. Stels also made a side exhaust which used the AERO case with the insignia ground off. I found the Stels piston cylinder setups to excel over all of them. Stels didn't plate the outside of the cylinder like AME or Norvel did.

[dave siegler]

All the sliver ones are not the short nose case.  I have several 061 that have the silver cylinder and the full length case. 

Yes the pic i showed was a early one with the D shaped venturi. 

And Dan I bought a few of them from Art J. 

[kenneth cook]

              While it's been mentioned in regards to the differences between AME and Norvel, I went searching in my engines . I have 4 engines in plastic bubble wrapped blister packages. 3 of them are AME engines which used a very large spring starter on the nose. These I truly believe are the earliest examples of AME engines. I also believe these cylinders are ABN. They could be ABC but they're certainly plated. I'm suggesting nickle due to the color of the plating. What I found interesting is that the last example I have has the paperwork listed as Northern Velocity MKII and the Norvel logo on the paperwork. The AME engine is dated 1994 while the Norvel Velocity LTD engine is dated 95.  These engines are connected and do share similar parts. My examples are very early examples. I probably own almost every version of these engines and I would love to share them in pictures but I can't figure out how to send them on here. If someone could provide a quick tutorial on how, I'd be much obliged as I have a lot of these examples to show.

[Reptoid]

           AME was originally the engine manufacturer, the case had AERO with a backwards E. They produced the Zeus which is what Dave shows in his picture. Later afterwards did AME become the cylinder designation. The cylinder will interchange from a AME Zeus to a Norvel. The rod also works as well as driveplate. Early Norvel engines used the pinch type collet like the AME Zeus but later went with the D hole drive washer. AME Zeus engines were somewhat hit or miss, you either had a good one or a bad one. Stels also made a side exhaust which used the AERO case with the insignia ground off. I found the Stels piston cylinder setups to excel over all of them. Stels didn't plate the outside of the cylinder like AME or Norvel did.

Stels (Russian)actually made the originals and all the others were copys. Gievski was the original designer, builder, and seller of the Stels. The original Stels had twin round angled to the rear exhausts and the later versions had single side exhaust. None of them had any brand markings on the case, had the bathtub shaped venturi which was too big for suction feed, were all .049-.050, and they were ABC. They came with pretty low quality head clamp and glow plug. Luckily the threads were the same as a cox plug so we used those and then used the Doug Galbreath head button with a nelson plug (best for high performance). Don't believe the hype from Norvel; the ABC piston/cylinder is superior in every way. The bottom engine case in Dave's post above is a Stels.