hsukaria

That conversation slipped past me.

hsukaria

So, the busted crankpins from Sig were on glow engines since the gas version did not exist back then. So it seems that it may be a manufacturing defect causing the crankpin shearing.

modelaircrafter

Yes, on glow. The other failures were severe scoring of the cylinder. No peeling of the piston was found. Here, I'm making an assumption but this one had a very, light brown colour as if it wasn't anodized long or deeply enough. All the others had the deep brown finish. One had a rod snapped in half with a hole punched in the side of the case. My sense at the time was that these engines had been overprimed and whacked with the starter. If the rod is too slim and the crankpins had faulty heat treating,,, what would you expect.

Under THOSE conditions, add a fixed, high compression head and well. But with diesel, you sneak up on the required compression. And again, kerosene has lubricating properties on it's own and with 20% oil,,,, that's all a good thing.

If the instructions call for 14% oil,,, I can't imagine running any engine with that little oil. The rod is the first to go. But given anodized aluminum's propensity to seize up with inadequate oil, that doubles the potential for failure. .

I have a small can of the Enya oil which I have to assume has special properties that allow for the use of bushed rods. For those with the climate to run engines at this time of year, I would be happy to donate some for at least one run of say, 8 ounces of fuel. Let me find out what percentage Enya recommends.

A side note. The Sig rep I dealt with told me that when a broken engine was returned to them, they replaced it, free of charge. I don't recall who paid the shipping back to the customer.

Charley

My Feedback: (2)

What got me at the time was that after it quit, it turned over freely when flipped and had good compression. Choke it and it started right up. Throttled OK too, when running. I though it might be over compressed so I added shims. It ran longer but still quit. It had bubbles in the fuel line while running which I took as an air leak in the fuel line or tank. I put clamps on every connection, no help. earwb opined that when the carb got hot enough it was vaporizing the gas in the carb, thus the bubbles. But the carb is first in the prop blast and wasn't too hot to touch while running.

If you have a problem with this engine you can't talk directly with the the factory techs so you don't know how they went about testing the engine. My question is: did they run my engine for 5 minutes or so? If all they did was a short run then the problem didn't manifest itself. No way to ask.

The main reason I went to the expense of sending my engine back to the factory was to find out what was wrong. I sent a detailed letter with the engine outlining what was wrong and stressing that it had to be run for 5 minutes or more. Don't know if anyone read it. But all I got back was filtered through Dmitry in CA, a sales rep. Very frustrating.

CR

modelaircrafter

Well, where have I contradicted myself? BC Bud.

modelaircrafter

Sounds like it's leaning out in the air. Tank location can cause this. Lines too small. Poor fuel draw due to the bore in the throttle barrel too large. Aside from the more tapered needle, offered after the fact, is the throttle on the GX same as the AX?

hsukaria

Sig was incredibly generous with their engine support. I had originally purchased the bushing version of the 40 (BigMig) and had some trouble tuning it. They asked me to ship it back to look at it. They returned a more expensive AX-40 with shipping paid. No hassles.

As far as the 14%, remember this is on gas, which has more lubricity than methanol.

hsukaria

All the same carb except the high speed needle. I never compared the low speed needles though.

I had the air bubbles in the fuel line. What you have to do is add a fuel filter not only to filter the gas (which is dirty from the gas station pump), but it also gets rid of the air bubbles in the fuel line. I seem to recall that earlwb recommended a specific filter for the sole reason that it eliminates the air bubbles. This could be a reason you (Charley) are having trouble with that engine. You are having to richen the needle to account for the air bubbles, but what you get is inconsistent fuel mix.

modelaircrafter

A quick search on the Enya gasser gives us a bit of info. http://www.modelairplanenews.com/blo...a-closer-look/

As far as I have been able to determine, the only modifications Enya has made to their standard glow ignition 180X and the 180X-GS is to use a larger head for increased cooling with a higher compression ratio and the inclusion of a Walbro carburetor. This head in conjunction with the special Glow plug and special oil result in the engine running on gasoline.

This special oil carries a rather unusual name of being an “Ester System” Chemo syntheses oil and has been developed by NSi Moka, a Japanese racing oil manufacturer for which a patent has been applied for. I asked Ken Enya, who heads Enya, if one of the chain saw/leaf blower or 2-stroke air cooled outboard oils could be used and was told no. Appearance wise, the glow plug is much like a standard glow plug, however, it utilizes a 6m-J thread, and has four notches on the nose. Again, inquiring about the purpose of the notches, I was told they influence the ignition and increase combustion efficiency. Like the special oil, a patent has been applied for for the plug. I would have to speculate that this special oil must have a catalytic affect on the special material used in the glow plug element much the same as methanol does on the platinum element in standard glow plugs.


The engine is of ABC design, but also utilizes a single expansion type ring, develops 3.2 hp @ 8,000 rpm and weighs 3lbs. 4ozs. Propeller sizes range from 18 x 10 through 20 x 8. Bill Jensen, who has been an approved sales, parts, and service center for Enya since 2007, conducted some comparison tests between the Enya 180X-GS and Super Tigre 3000 (1.8 cu. in.) with the Super Tigre using 5~ nitro glow fuel. The Enya turned an 18×10 Zinger 6,900 rpm versus the SuperTigre’s 6,800 and a 20 x 8 Zinger 6,700 rpm versus the SuperTigre’s 6,400. Pretty amazing when you consider that gasoline burning engines generally turn 800 – 1,000 rpm lower than an equivalent engine burning glow fuel. Bill also had the Enya idling as low as 1,400 rpm with good acceleration and deceleration characteristics.

The engine does carry a pretty stiff price of about $1,100 depending on the current exchange rate with an optional Pitts-style muffler being $130.00 extra. A 50ml can of the special oil costs $39.00 and is good for four gallons of fuel when mixed at a 30 to 1 ratio. With gasoline running close to $4.00 a gallon here in the Los Angeles area and one quarter of the oil costing $9.75 you come up with a fuel cost of $13.75 a gallon. With a gallon of 5% nitro glow fuel running in the $20.00 range, you are experiencing approximately a 36% saving.
With gasoline burning at approximately half the rate of glow fuel, the savings becomes even greater. Whether this would justify the additional cost of the engine would depend on how much flying you do. Although I have not had one of the Enya 180X-GS engine in my hands one is coming my way. However I am sure the quality and workmanship are typical of the other Enya engines I have reviewed or examined—Equal to the best.


So Enya had to increase cooling area. They also came up with a unique glow plug design that carries a special element. Then they provided a special oil that will run on a bushed conrod at only 3% in the mix.

The oil is expensive but you won't go through it as quickly in a .40 compared to the Enya. Especially at 3% in the mix.

I have the oil, this is going to be interesting. But there's still that special plug. I have them and the proper tap. This is going to be fun.

modelaircrafter

Geez, what if I could use only 1% of the special oil in a diesel. That would allow for a 19% additional kero to deliver more power. Maybe glow too?

hsukaria

There is an Ester based oil that is used in glow engines in Europe that only requires about 10% mix rather than 17-20% like we use here in the US. But that oil is quite expensive also.

I think a big factor in tuning the GX-40 is that it is not using a Walbro-type pump/regulator carb. That coupled with the air bubbles and using the muffler pressure all contribute to tuning challenges. That is why I see all other gassers using some sort of pump/regulators even if they are using a glow plug (including the Enya and OS). That is what I was planning on doing when I go back to the GX-40, to close off the muffler pressure tap and drill out a tap into the crankase (it already has a designated spot). Then I can put a gas pump/regulator like this one I hacked up. I kept the 4 bolts long for now until I figure out how to mount it. This is off a Walbro knockoff carb that has the regulator and pump on the same side of the throttle body. I just sawed off the throttle body. That carb is only around $11 shipped to your door. But I have not tested it yet to verify performance.

modelaircrafter

My concern when experimenting with the Tanaka was that the Walbro type carb was set up for gas. As I wanted to experiment with glow and diesel, I needed a means to play with the high and low end mixtures. I installed the throttle from the OS .108. The barrel bore was 2 mm bigger than the stock throttle so in it want. Interestingly, in the cold, the carb body started to ice up.

https://www.youtube.com/watch?v=z5fK1NWDLS4

modelaircrafter

Here's the Picco .06 converted to the Enya gasser plug and their special oil. https://www.youtube.com/watch?v=8aWnU95--FI

Uploaded on Dec 4, 2011
This is the first run of the Enya gasser glow plug using Enya's oil at 5% with premium gas. Using glow fuel prime, it lit right off but wouldn't keep running. The needle was set at the glow fuel setting at 1/2 turn out. For gas, the needle needed to be taken out, just 1/4 turn.

Discussion on RCU revolved around needle sensitivity and airflow in the carb. Greg was correct in his estimate as to what we would find. One click of the needle lean and the engine immediately sagged and died. The optimum setting appeared to be a half click leaner.

The bore on the carb was ideal for glow but is too large for gas. Evidence of this is that the engine would only idle at half throttle. Any lower and it would quit.

Power is down at just under 16K but we suspect that we don't have the compression ratio optimized. We'll be making a new head button with half the combustion chamber volume. If this is too small, we can add shims to find the sweet spot.




PS,

I never did make a new head with higher compression. On my to do list this year.

modelaircrafter

In the sidebar of the Picco, I found this run of the GX. https://www.youtube.com/watch?v=cE3l1zdJcPw

Sounds too rich, won't settle down to a smooth run, idle is erratic. Maybe needs a hotter plug?

modelaircrafter

Here's the Picco .06 using gas and the Enya oil but with a turbo plug. https://www.youtube.com/watch?v=YiF0-i9J618 Runs smooth with the clip on but struggles and quits without. My conclusion was that the plugs I was using were too cold. That may have been wrong, will have to do these experiments again but with a shaved head for more compression and shims to adjust.

Charley

My Feedback: (2)

Andy, a few excerpts.

Well, the GX40 runs.

OK, I flood it, get a hydraulic lock, apply a starter, bend the rod but it's not my fault. C'mon man.

A rod that will bend in a hydraulic lock but not shear the crankpin, causes the crankpin to shear?


Huh? Neither?

No need to assume; look at the head insert to see which plug it is designed for.

What's "BC" mean?

If SIG replaced a bunch of NV engines but no longers carries them I can see why. Good for SIG! Wish I'd known.

CR

modelaircrafter

Charley,

Thanks for the fair criticism. Yes, I misspoke here and there and didn't make myself clear.

BC stands for British Columbia, best bud on the planet. But actually, I'm on Rx painkiller for back pain.

Let me put it this way. Enya modified their big glow engine in a number of areas to make it work. I experimented with the Picco to try and learn more about how it works. All Norvel did was to give you a high compression head and tell you to use less oil. Rods bend and pins break.

Pins break even on glow, I have two Norvel .15 cranks with the pins snapped off. Not by me, these were Sig returns.

However, broken pins are not something that I have encountered much in my 50 years of running engines. I only had that happen once to an AME .049 with the pin drilled out. As I recall, I was hand starting.

OK, I'm going to cool it for now, and wait till I actually try the Norvel .40 on gas. I think that the carb has a lot to do with it and I have dozens of those to play with. And lots of spare cranks.

Again, thanks,

Andy

modelaircrafter

Having gone to the doctor and getting my pain prescription adjusted, I feel safe posting again. The issue is, is that while I can try to duplicate the gas head that comes from the Norvel factory, I have no idea as to the combustion chamber volume the factory head holds.


For anyone who has given up the gasser and converted back to glow, and the head is languishing as dead capital, I’d like to buy the head along with the plug that Norvel recommends. That is, if you’re asking no more than the original cost. This would help a lot, sent as a gift and all,, which it would be. I have PayPal


I would use the Norvel gasser button as a guide to do that. I also have a means of determining the volume of the Norvel head combustion bowl helping to make an identical Enya head including its special plug.


I’ll use the original, .40 glow carb and work from there. I have a half dozen, .40 carbs of other brands, some which are drop ins. I have the .25 Norvel carb which I recall is also a drop in replacement. I have OS and GMS and cloned carbs in the .25 size. Some of these have drop in bores, more tapered and less tapered needless giving variations on high and low end adjustment. Even simple, adjustable air bleeds. And who knows maybe a .15 carb might be “the One” ( Matrix).

The .40 I'll be using is Ball Bearinged, has the MVVS heavy duty rod and has been run extensively on the rigours of diesel combustion, including a couple of hydraulic locks. On the starters which I use, on all my work on the Novels, hydraulic lock just stalls the starter.

Preliminary work to start, bench runs will be in two months.

See Y'all then.

PS
I've been told that Maui Wowee is actually the best bud in the world. ;*)

aspeed

Sounds like a fun project. I think the plug is an OS P3, which is an ultra hot. I noticed there are two versions, one is a race version. On the corner of the screen I noticed a price for a turbo plug of $28 CDN. I hope that is not a sign of things to come.

Charley

My Feedback: (2)

Out of curiousity I looked it up on Tower Hobbies. Looks like $14.81 CDN to your area, S&H included, for one plug. The gold plated one is a bit more.

CR

hsukaria

NV Engines sells spares and plugs for their engines also

aspeed

Different plug, but this came up on my screen http://www.ebay.ca/itm/like/112169702843 yikes, I'll have to take up stamp collecting or knitting for a hobby. I go through plugs as I like to jack up compression, and work down. Not creep up on it.

modelaircrafter

Any wonder why I'm a fan of diesel? All the fuel ingredients are available locally. All the myths of diesel operation have been busted. Kerosene is cheap. Benol is available locally if you have a dirt bike or snowmobile shop nearby. We have both. Quickstart at your automotive parts store. Resin catalyst too and cheap. And, potentially, you may not need a special head. Just install 4 or 5 gaskets,,, take one out, one at a time till your prime fires off and go from there. You MAY have to install a .25 carb, or maybe not. This will be tried on the .40 in question. And maybe you don't even need a stronger rod. Maybe.

Yes, diesel has a unique aroma. Me, I love the smell of diesel in the morning. (Full Metal Jacket). It all depends on your perspective.

Found it. Here's the .15 with just a disc in the head. Cost? .25 cents and an hour of time.
https://www.youtube.com/watch?v=Ilzx6EGGe9o Note that there's no plug or adjusting screw. And listen to that idle.

modelaircrafter

Here, https://www.youtube.com/watch?v=quMB65_tUxo is the same engine, with adjustable head, running on 80% mineral spirits and 20% Benol. NO ether and NO ignition improver. Someone once said that diesels are like goats, they'll eat anything.

This reminds me that I always wanted to try WD 40 as fuel. Smells nice. and if I recall correctly, in gallon cans it wasn't that expensive. If it fires off and runs, maybe you can leave out the oil.

modelaircrafter

Oh wow, https://www.youtube.com/watch?v=z5t-gMTdvPI And look in the sidebar. All KINDS of fuel to run in your Norvel, diesel .40