aspeed

Sorry about the lung problems. Does the gas require more compression , or less than methanol? I was always under the impression gas needed less compression, at least in a car which has a spark. If a gas Norvel head is a problem then it could run on methanol with the right shim.(or trimming down the head for more compression) The adjustable head you have is a good idea for those type of experiments. It would be interesting to see a drawing or disassemble head to show how it was done. I watched that video a few times and thought it was quite clever. I think I have seen most of yours.

AndyW

My Feedback: (1)

As soon as I get a good, charcoal mask, I'm going to try and resume some testing. The head was made some 6 years ago and I had planned to use it for glow and diesel work. But then, stuff happened and here we are. In that time, the Norvel gaser was offered and so now I have more fun comparing the characteristics of glow, diesel AND gas on the same engine. That should prove quite interesting. I'll have to be more scientific about it all, carefully documenting results and conclusions.

I'm sure that the engineers have all this figured out but the fun is in the discovery. For now, I suspect that glow combustion falls somewhere between gas and diesel. It's been said that glow is much like diesel combustion in that compression ratio is a big factor in ignition timing. Less critical with glow, if course, because of the hot element. If you've ever run a Cox at dusk or at night, you'll have seen the continuous glow at the exhaust ports.

About the head design,, well, it may have patent possibilities so no disclosure, for now. It wouldn't be something you'd put into production but may have appeal to engine designers, I'm guessing.

RDJeff

My Feedback: (11)

I've been following this thread since it started, read every page, and finally bit the bullet and bought one! I also picked up a slightly used one. I spent some time going through the thread looking for some information I thought I saw regarding different needles. It seems that with the two engines, I have two different needles. One has a long straight taper, while the other has a more blunt angle at the tip. If my memory serves me correctly, the longer taper works better, but I'd like to hear from the experienced among us.

I installed the used one in a Balsa USA Phaeton II, and due to the light weight of the engine, and some weight saving practices, the all up weight came out at 5 pounds 9 ounces, against the manufacturer's listed weight of 6 - 6 3/4 pounds. I hope to get it in the air soon!

DaOldGuy

If you really like that Phaeton, get high quickly and stay in a pattern that is acceptable to glide in from any point. 8)

hsukaria

Before the last flight where the crankpin broke off the crank, the two previous flights were the only landings out of about 20 flights that were not deadsticks. Luckily, I had that engine installed on a plane that has no problems with deadsticks.

hsukaria

If I get my GX-40 working again, I would use this with it: https://www.rcgfusa.com/10cc-carburetor-oil-pump

triumphman49

My Feedback: (149)

HUSKARIA, Haven't seen that before and web site didn't appear to have much info. Is this a "fuel pump \ smoke pump"? Any idea if it's similar to perry , Cline or Iron Bay pumps?

Many Thanx
Mike

hsukaria

No, not sure if it will work. The 10cc RCGF gas engine and the 9cc NGH gas engine have their pump carb split into 2 parts because a full Walbro type carb won't fit on them. I thought maybe the separate part might work on the NV GX-40?

triumphman49

My Feedback: (149)

Thanks for the quick reply, the RCGF 10cc looks interesting, sure wish NV would get off the pot and bring out their 10cc size engine.

Mike Brennan

hsukaria

They better first redeem themselves from their sins on the GX-40 breaking off crank pins.

I have seen a couple of youtube videos of an NGH 9cc running on the new OS G5 glowplug instead of the spark ignition. It is possible that the RCGF 10 and Evolution 10 engines might also run on the G5 glowplug. They would still have the advantage of a pumper carb over the NV engines regular carb that is so touchy. They also require quite a bit less oil in the fuel mix.

erieqc

You can buy a os ggt10 for $245.00

Charley

My Feedback: (2)

Hmmm, I wonder. When my GX-40 dies, I have to choke it to restart it. OTOH, the tank height doesn't seem to matter. It almost seems as if it develops an air leak as it heats up. Can we still get the Cline/Iron Mt. reg?

CR

aspeed

I have had the overheating problem on glow motors too. The crank/crankcase seal was too tight, which made the bottom end hot. It gave the same effect you seem to have. Maybe just vapour lock. Gasoline may make this more of a problem than glow. To fix it? maybe more air to circulate around the motor? I don't know.

Charley

My Feedback: (2)

Never heard of a front seal being too tight. My engine is completely exposed on the nose of the model. I thought maybe it was over compressed so I added a pair of head shims. It still conked out but it ran longer before it died.

I may try it on glow fuel for the helluvvit.

CR

Charley

My Feedback: (2)

Where?

CR

downunder

I've seen your video before and your head looks the same as the one I made nearly 20 years ago for my Enya 60X. My reason for making it was because I wanted to find the optimum compression for zero nitro fuel which is all I ever use. I even used the same type Cox spanner for the adjustment . Raising compression from the standard 8.8 to 13.5:1 gave a HP increase of 20%. It could of course be used to optimise compression for any amount of nitro.

The photos show how it was done. I used a 32TPI thread for fine adjustment and the O ring was just a normal black rubber which held up perfectly but a Magnum I converted needed a Viton seal to stop the seal from melting.

earlwb

That is a pretty neat idea actually. Adjustable compression for a glow engine. Nice.
Way to go. I like it.

erieqc

World Hobbies

Charley

My Feedback: (2)

OK, so from OZ + S&H = ~$275 depending on the exchange rate. You devil!

CR

hsukaria

Fellas, checkout my add in RCU. I plan on converting the GX-40 back to AX-40 to avoid shearing another crankshaft pin. You might get lucky and not have the same problem

http://www.rcuniverse.com/market/ite...874&electric=0

DaOldGuy

Mine was shipped to Russia... Have not heard from it in a while.

Charley

My Feedback: (2)

Did you ship it on your own? I'd do the same if I had an address and a contact person to send it in the attention of. The only thing I haven't tried is to find some high octane ethanol-free gas to run it on.

CR

hsukaria

If you still want to try it, you could purchase a quart of the pure gas at a hardware store. They come in 2-stroke premixed with oil and 4-stroke pure gas. Get the 4-stroke pure gas and add the benol to it. Not cheap, but would help isolate the ethanol question. I used the first quart with that pure gas from the hardware store and then transitioned to Premium gas-station pump gas for the second quart before the crankpin broke off. But having to purchase the expensive pure gas from the hardware store would negate the cost benefit of this engine since it would be as expensive as glow fuel.

Charley

My Feedback: (2)

I can get ethanol-free 87 octane here in town now but the engine instructions call for 93 octane. I could add some octane booster if it knocks. Avgas? Maybe.....

CR

hsukaria

The gas I used from the hardware store was 91 octane and that didn't cause any problems.