Testing the new NV (Norvel) .40 size (6.5cc) gasoline glow engine
#1

Thread Starter

Hi guys,
Wasn't sure on the forum but this is a glow engine, no ignition, no pumper carb, and starts with a prime and a glow igniter like we have all been using for years. All the other gas engines I've used have been large, heavy, and had complex ignition systems.
This is less than 11oz w/o muffler, spins a 10X7 APC at 13,500rpm and sips fuel like a 25. I've been using premium pump gas in it and have'nt had a flame out or dead stick yet. I've been flying it in a WM LA racer that I had been flying for a year with a NV .40 nitro engine in with no complaints, so I figured it was a logical move. So far it flys with more power, less fuel, and I find the power throttles up much smoother and quicker than standard gasoline engines. I've included a video of it pulling a 46 size plane with some good authority.
[youtube]http://www.youtube.com/watch?v=ykJkVXeCaMI&feature=plcp[/youtube]
Wasn't sure on the forum but this is a glow engine, no ignition, no pumper carb, and starts with a prime and a glow igniter like we have all been using for years. All the other gas engines I've used have been large, heavy, and had complex ignition systems.
This is less than 11oz w/o muffler, spins a 10X7 APC at 13,500rpm and sips fuel like a 25. I've been using premium pump gas in it and have'nt had a flame out or dead stick yet. I've been flying it in a WM LA racer that I had been flying for a year with a NV .40 nitro engine in with no complaints, so I figured it was a logical move. So far it flys with more power, less fuel, and I find the power throttles up much smoother and quicker than standard gasoline engines. I've included a video of it pulling a 46 size plane with some good authority.
[youtube]http://www.youtube.com/watch?v=ykJkVXeCaMI&feature=plcp[/youtube]
#3

Thread Starter

Thanks,
Once I get some more time on it and gather more specs I'll do more of an in-depth review. For now I've just been flying it, trying different props, and seeing how it handles in the air. It's super efficient to fly, gas is cheap, and makes for a simple day at the field
It makes more power than the nitro version and burns less fuel to boot. Which says a lot as the nitro version is a fuel miser. So far I haven't found any bad habits or weak spots in it. I have found that the standard Tygon fuel line doesn't work well at this size engine, that stuff is made more for a larger engine with a pumper carb. Plus this one pressurizes the fuel tank (standard muffler nipple) so it quickly seperates the good tank stoppers from the cheap ones.
Bill
Once I get some more time on it and gather more specs I'll do more of an in-depth review. For now I've just been flying it, trying different props, and seeing how it handles in the air. It's super efficient to fly, gas is cheap, and makes for a simple day at the field

It makes more power than the nitro version and burns less fuel to boot. Which says a lot as the nitro version is a fuel miser. So far I haven't found any bad habits or weak spots in it. I have found that the standard Tygon fuel line doesn't work well at this size engine, that stuff is made more for a larger engine with a pumper carb. Plus this one pressurizes the fuel tank (standard muffler nipple) so it quickly seperates the good tank stoppers from the cheap ones.
Bill
#4
Senior Member

Imiss my 40AX it was a good runner, too bad it lost its liner. And it died so young. Ithink it was something it ate.
#5

My Feedback: (1)

ORIGINAL: hllywdb
Hi guys,
Wasn't sure on the forum but this is a glow engine, no ignition, no pumper carb, and starts with a prime and a glow igniter like we have all been using for years. All the other gas engines I've used have been large, heavy, and had complex ignition systems.
This is less than 11oz w/o muffler, spins a 10X7 APC at 13,500rpm and sips fuel like a 25. I've been using premium pump gas in it and have'nt had a flame out or dead stick yet. I've been flying it in a WM LA racer that I had been flying for a year with a NV .40 nitro engine in with no complaints, so I figured it was a logical move. So far it flys with more power, less fuel, and I find the power throttles up much smoother and quicker than standard gasoline engines. I've included a video of it pulling a 46 size plane with some good authority.
[youtube]http://www.youtube.com/watch?v=ykJkVXeCaMI&feature=plcp[/youtube]
Hi guys,
Wasn't sure on the forum but this is a glow engine, no ignition, no pumper carb, and starts with a prime and a glow igniter like we have all been using for years. All the other gas engines I've used have been large, heavy, and had complex ignition systems.
This is less than 11oz w/o muffler, spins a 10X7 APC at 13,500rpm and sips fuel like a 25. I've been using premium pump gas in it and have'nt had a flame out or dead stick yet. I've been flying it in a WM LA racer that I had been flying for a year with a NV .40 nitro engine in with no complaints, so I figured it was a logical move. So far it flys with more power, less fuel, and I find the power throttles up much smoother and quicker than standard gasoline engines. I've included a video of it pulling a 46 size plane with some good authority.
[youtube]http://www.youtube.com/watch?v=ykJkVXeCaMI&feature=plcp[/youtube]
Inquiring minds need to know.
Ray
#7

I'd take a guess and say the petrol (gas) has a fair proportion of ethanol in it, enough to keep the plug lit.
#8
Senior Member

Whatever happened to the OS' attempt at such an engine?
(or was it Enya?)
You had to buy special fuel from the manufacturer, as I recall ... or special oil. Or something. And jazzy plugs, too.
I've just realised that I know bugger-all about this subject. Someone enlighten me, please.
(or was it Enya?)
You had to buy special fuel from the manufacturer, as I recall ... or special oil. Or something. And jazzy plugs, too.
I've just realised that I know bugger-all about this subject. Someone enlighten me, please.
#9

Thread Starter

Hi Ray,
As I said, I'm not quite ready for a full review yet, but I'll share what I've found thus far.
From the outside, the case mounting is identical to the nitro 40 (as in the 46) so it is a simple bolt in affair as far as mounting goes. They did not feel the need to make the case any larger for the gas, and I can agree with them on this point as the 40 case is quite robust as is. NV tends to build a strong, lightweight case by using high grade materials and good design, rather than use a big, clunky casting. Unfourtunatley I have "tested" this on a few occassions as I tend to push the envelope with my flying so I never get those nice crashes where you bend the landing gear and break a prop. Mine tend to look more like the old Wide World of Sports "The Agony of Defeat" newsreels
Even when I have to do a bit of digging on the field to get the nose of the plane out I have yet to break one of their cases, enough said.
From there, things start to change. The head button is different in a number of ways. First off it takes a different glow plug, not a standard glow or 4-stroke. It is also a bottom sealing plug, like the Nelson plugs we use on the .061 and Cox motors, but a different configuration and they will not interchange. The button itself is also a different design and made just for this motor. If you had any of the early NV 40's you might remember they also included three set screws to do the final locking of the head button. They discontinued them after a while, but they are back for this motor, perhaps due to the increased power or the differences in the way the fuel burns.
Moving on to the carburator it becomes apparent that this motor was "designed" for gasoline, not just adapted like a disel conversion. The carburator is larger in many ways. The bore is larger, which may explain some of the increased power but I suspect it has more to do with proper atomization of the fuel. Both the high speed and low speed needles are also larger and made for the motor as is the NVA tubes. The design seems to be well thought out and tested as it pulls the heavier fuel without the need for a pump or butterfly carb.
Another welcome change is the option of a "straight out" muffler in addition to the standard "tilt down" version of the 40 Nitro. This makes fitment in a cowl much easier and gives more mounting options.
In opperation, like all gasoline motors, you need to get it wet to start as gasoline ignites much differently than glow fuel. Since there is no pump or choke, you prime it just like a standard glow motor. I have found that because gas motors need to warm up a bit, without a choke or butterfly, it works best to richen the needle 1/4 turn or so when stating cold. I tend to do this as a standard practice on cold starts on all my motors anyway as the majority of early engine failures I see at the field are due to lean runs. Once running, the standard practice of setting it 300 to 500 rpm off of peak holds especially true on this motor as you are pulling thicker fuel without a pump. This will yield a nice flight with no tendacies to lean out at the top of a vertical "8", great idle, and smooth, dependable power transitions.
Speaking of needle settings, I have yet to adjust the low speed needle, or have the need to. This does not surprise me as NV has made a practice of designing their carbs and ramps to meter fuel at a very precise level. To this end their 15 and 25 motors are available with a 2 needle carb or a single needle without even an air bleed adjustment. I have some of each and find little difference in actual use. My .074 idles like a swiss watch and has no airbleed or low speed needle. But I am happy to have the low speed needle there, just as I like having extra switches on my radio. Not that I uses them all, but you never know
I have not done any actual measuring of ports between the nitro and gas motors, so I can't comment on changes there. The motor definatley makes more torque than the nitro version, as it will swing a bigger prop at the same rpm. This may be due to the gas burning a bit slower than the nitro and giving it a longer "push" on the piston, much like using a slow burning powder in a rifle. This issue is best left to the engineers to debate. Also to note, like the rest of their motors, the gas motor also keeps running stronger and smoother the more flights I put on it. The only low speed adjustments I have made are to keep lowering the idle as it gets more time on it. It has yet to flame out or quit on idle, even after a few bumpy landings on windy days and always throttles up nicely on touch and go's.
Please ask if I have left anything important out so far,
Bill
As I said, I'm not quite ready for a full review yet, but I'll share what I've found thus far.
From the outside, the case mounting is identical to the nitro 40 (as in the 46) so it is a simple bolt in affair as far as mounting goes. They did not feel the need to make the case any larger for the gas, and I can agree with them on this point as the 40 case is quite robust as is. NV tends to build a strong, lightweight case by using high grade materials and good design, rather than use a big, clunky casting. Unfourtunatley I have "tested" this on a few occassions as I tend to push the envelope with my flying so I never get those nice crashes where you bend the landing gear and break a prop. Mine tend to look more like the old Wide World of Sports "The Agony of Defeat" newsreels

From there, things start to change. The head button is different in a number of ways. First off it takes a different glow plug, not a standard glow or 4-stroke. It is also a bottom sealing plug, like the Nelson plugs we use on the .061 and Cox motors, but a different configuration and they will not interchange. The button itself is also a different design and made just for this motor. If you had any of the early NV 40's you might remember they also included three set screws to do the final locking of the head button. They discontinued them after a while, but they are back for this motor, perhaps due to the increased power or the differences in the way the fuel burns.
Moving on to the carburator it becomes apparent that this motor was "designed" for gasoline, not just adapted like a disel conversion. The carburator is larger in many ways. The bore is larger, which may explain some of the increased power but I suspect it has more to do with proper atomization of the fuel. Both the high speed and low speed needles are also larger and made for the motor as is the NVA tubes. The design seems to be well thought out and tested as it pulls the heavier fuel without the need for a pump or butterfly carb.
Another welcome change is the option of a "straight out" muffler in addition to the standard "tilt down" version of the 40 Nitro. This makes fitment in a cowl much easier and gives more mounting options.
In opperation, like all gasoline motors, you need to get it wet to start as gasoline ignites much differently than glow fuel. Since there is no pump or choke, you prime it just like a standard glow motor. I have found that because gas motors need to warm up a bit, without a choke or butterfly, it works best to richen the needle 1/4 turn or so when stating cold. I tend to do this as a standard practice on cold starts on all my motors anyway as the majority of early engine failures I see at the field are due to lean runs. Once running, the standard practice of setting it 300 to 500 rpm off of peak holds especially true on this motor as you are pulling thicker fuel without a pump. This will yield a nice flight with no tendacies to lean out at the top of a vertical "8", great idle, and smooth, dependable power transitions.
Speaking of needle settings, I have yet to adjust the low speed needle, or have the need to. This does not surprise me as NV has made a practice of designing their carbs and ramps to meter fuel at a very precise level. To this end their 15 and 25 motors are available with a 2 needle carb or a single needle without even an air bleed adjustment. I have some of each and find little difference in actual use. My .074 idles like a swiss watch and has no airbleed or low speed needle. But I am happy to have the low speed needle there, just as I like having extra switches on my radio. Not that I uses them all, but you never know

I have not done any actual measuring of ports between the nitro and gas motors, so I can't comment on changes there. The motor definatley makes more torque than the nitro version, as it will swing a bigger prop at the same rpm. This may be due to the gas burning a bit slower than the nitro and giving it a longer "push" on the piston, much like using a slow burning powder in a rifle. This issue is best left to the engineers to debate. Also to note, like the rest of their motors, the gas motor also keeps running stronger and smoother the more flights I put on it. The only low speed adjustments I have made are to keep lowering the idle as it gets more time on it. It has yet to flame out or quit on idle, even after a few bumpy landings on windy days and always throttles up nicely on touch and go's.
Please ask if I have left anything important out so far,
Bill
#10
Senior Member

Does it run on ordinary petrol?
What is the oil content?
Is the big-end a plain bearing?
How much do the plugs cost? ... are they durable?
What is the oil content?
Is the big-end a plain bearing?
How much do the plugs cost? ... are they durable?
#11

Thread Starter

It runs on standard premium (93 octane) pump gas.
The final oil content has yet to be announced. I have tested 2 of these so far, with varrious oil ratios, etc.. The first one was for "torture testing" and seeing what it would tolerate, the second, final was more for flight testing and fine tuning for final production.
It is a ball bearing motor like the nitro version.
Not sure on the plug cost, I haven't had to replace one. For the record they only sent one plug and I am still using it even after all the abuse on the 1st motor, including varrious starting voltages and experimenting with a constant glow system. So I would have to term that "Highly" durable.
The final oil content has yet to be announced. I have tested 2 of these so far, with varrious oil ratios, etc.. The first one was for "torture testing" and seeing what it would tolerate, the second, final was more for flight testing and fine tuning for final production.
It is a ball bearing motor like the nitro version.
Not sure on the plug cost, I haven't had to replace one. For the record they only sent one plug and I am still using it even after all the abuse on the 1st motor, including varrious starting voltages and experimenting with a constant glow system. So I would have to term that "Highly" durable.
#12

Thread Starter

Hi downunder,
So far I've run it on Shell, Mobile, and Sunoco, all with the same results. Don't tell the gas companies as they spend a lot of money on advertizing to us how each one is better
As far as I'm concearned it has been all downhill since they did away with good old leaded Sunoco 260. But for the most part it's safe to say that any premium pump gas will be fine in it. I myself tend to stay away from the off-brands in any 2 cycle whether it be a weed whacker or outboard motor, like oil, it's cheap insurance.
So far I've run it on Shell, Mobile, and Sunoco, all with the same results. Don't tell the gas companies as they spend a lot of money on advertizing to us how each one is better

#14
Senior Member

I have heard that most any 2 stroke glow engine can run well on a mix of 30% glow fuel and 70% gasoline. The source stated that he simply blended 5% nitro-18% oil glow fuel with regular gasoline. The resultant oil was around 61/2%. Itwas run as a regular glow engine since there is enough methanol in the blend to allow the glow plug proper function (proper catalysis). I have also heard from the same source that carburetion is standard glow type without need to reduce the carb fuel passages. It does require a leaner needle than regular glow would.
I have not run any of these experimentsmyself....YMMV
Nevertheless, this is an interesting development. I am particularly interested in the carburetor design and if it can be built for larger gasoline engines in the 30-60 cc area. A contact would be great
#15

Yeah, hllywdb, we need contacts, info, etc...
I have an AX-40 that I am installing in a new plane as we speak. It would be great if I can modify it to gas.
I have not seen anything in the www.nvengines.com website regarding this engine. Must have been a secret development. I know they talked about a new 60 engine.
The Norvel/NV engines have the screw-on head cap and button. So swapping those out for the special gas version or even a diesel adapter would be quite easy.
I have an AX-40 that I am installing in a new plane as we speak. It would be great if I can modify it to gas.
I have not seen anything in the www.nvengines.com website regarding this engine. Must have been a secret development. I know they talked about a new 60 engine.
The Norvel/NV engines have the screw-on head cap and button. So swapping those out for the special gas version or even a diesel adapter would be quite easy.
#16

ORIGINAL: hllywdb
Hi downunder,
So far I've run it on Shell, Mobile, and Sunoco, all with the same results. Don't tell the gas companies as they spend a lot of money on advertizing to us how each one is better
As far as I'm concearned it has been all downhill since they did away with good old leaded Sunoco 260. But for the most part it's safe to say that any premium pump gas will be fine in it. I myself tend to stay away from the off-brands in any 2 cycle whether it be a weed whacker or outboard motor, like oil, it's cheap insurance.
Hi downunder,
So far I've run it on Shell, Mobile, and Sunoco, all with the same results. Don't tell the gas companies as they spend a lot of money on advertizing to us how each one is better

#17

My Feedback: (3)

ORIGINAL: bogbeagle
Whatever happened to the OS' attempt at such an engine?
(or was it Enya?)
You had to buy special fuel from the manufacturer, as I recall ... or special oil. Or something.
Whatever happened to the OS' attempt at such an engine?
(or was it Enya?)
You had to buy special fuel from the manufacturer, as I recall ... or special oil. Or something.
#18

Thread Starter

It will be available from NV at [link]http://www.nvengines.com[/link] Most likely early next year provided it passes all of their long term testing. They will probably announce it once they have sufficient stock available.
I doubt that this will be a conversion kit, as too many things are different. I swapped a standard 40 NV carb on one just to see and it won't work either. Like I said, this one is realy designed to run gasoline.
I doubt that this will be a conversion kit, as too many things are different. I swapped a standard 40 NV carb on one just to see and it won't work either. Like I said, this one is realy designed to run gasoline.
#19

Thread Starter

bogbeagle, I think it was the Enya 180 that they did that on. OS may have tried it as well. The bigger you get, the easier it is. We use to start our old Farmol tractors on gasoline then switch them over to kerosene (This one is dating me)
I'd hate to have to buy engine, plugs, fuel, and everything just from a manufacturer, but then again, I liked the old Fox mistle mist
I'd hate to have to buy engine, plugs, fuel, and everything just from a manufacturer, but then again, I liked the old Fox mistle mist

#20

There was a lot of talk about this about a year ago. Special glow plug and oil to make them run, here is Enyas engine; [link=http://www.modelairplanenews.com/blog/2011/10/12/enyas-180x-gs-gasglow-engine-a-closer-look/]Enya gas engine[/link]

#21
Senior Member

Yes, that's the one.
Bio-fuel (over here) is about 90% petrol, I think. Some of it is 95% petrol. The remainder is methanol. I have a feeling that the OS used a special fuel, brewed by OS.
Can't remember.
Bio-fuel (over here) is about 90% petrol, I think. Some of it is 95% petrol. The remainder is methanol. I have a feeling that the OS used a special fuel, brewed by OS.
Can't remember.
#22
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I am going to definitely keep an eye out for this engine, sounds like a real winner!!! Please keep us up to date on release dates, Est. Prices, etc.
Thanks, Craig..
Thanks, Craig..
#23

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What exactly does this NV run on? Gas, Nitro or a mix of both?
I looked on the NV site and there is nada about it...
Very interested though!!
Bill S.
I looked on the NV site and there is nada about it...
Very interested though!!
Bill S.
#24

Thread Starter

H Bill,
This motor runs on 100% pump gas, just like a DA or DLE. No glow fuel or nitro added, just oil. More of a KISS approach, which means even I can figure it out
This motor runs on 100% pump gas, just like a DA or DLE. No glow fuel or nitro added, just oil. More of a KISS approach, which means even I can figure it out
