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Old Mar 30, 2012, 10:47 PM
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Originally Posted by earlwb View Post
I plan on using Coleman Lantern fuel or camp fuel in it as the Naptha doesn't stink as much as the gasoline does we have here in the USA.
I would think twice about using naptha, it is a very dry fuel and can attack rubber parts over time. I know we use to use a high octane naptha/gas fuel in our race engines when we couldn't get racing fuel but, Coleman fuel is low octane and it doesn't work as good as high octane racing fuel does today. see: wikipedia on Coleman_fuel

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Originally Posted by earlwb View Post
Also our USA gas has ethanol in it and in some areas a lot of ethanol in it and the ethanol may be damaging to the pump and carb diaphragms and valves. I remember a lot of guys complaining about their gasoline RC engine's pump carbs going bad fairly fast using our USA gas in them.
Up here in Canada we have had 10% ethanol fuel for 30 years now and I haven't had any problems with it in any of my 2 or 4 stroke equipment, from weed wackers to my 74 GTO. E85 or 85% ethanol is different, it hardens rubber diaphrams and you need to rejet carbs and adjust ignition timing to run it. Also methanol (glow fuel) is more corrosive than ethanol to aluminum.

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Originally Posted by earlwb View Post
So apparently the RC gassers have different pump parts inside than our weed wackers and lawn mowers, chain saws and leaf blowers do. As our utility engines don't seem to be affected by the ethanol in the fuel.
The parts are the same but, Walbro does offer a diaphram kit that includes some parts that can be used in high alcohol fuels. See my next post.

Ray
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Old Mar 30, 2012, 11:18 PM
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Canada, MB, Winnipeg
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Possible gasket parts

I was looking up some parts for another carb but came across a gasket kit that might work on the NGH fuel pump. I say might because the parts look correct but not having a NGH pump and the Walbro kit in my hands it is hard to say. The Walbro gasket/diaphram kit sells for $4.34, so it's not a major expense to try. Take a look at the pictures and let me know what you think. I think the Blue gasket would be either plastic or silicon and more compatible with glow fuel?

Ray
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Old Mar 31, 2012, 06:17 AM
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That sure does look close like it ought to work for sure. But what I was commenting about was that our weed wacker and other utility engines run just fine using pump gasoline here in the USA. But the gasoline engines we buy for RC plane use seem to have problems using our pump gasoline. I have seen numerous guys have problems after a short while of usage. Other guys rebuilt their carbs or replaced the carbs and switched to Coleman Lantern Fuel instead and then they didn't have problems. So there must be something causing the problem with our USA gasolines.

I almost forgot about it, but Lowe's and Home Depot now sell quart cans of gasoline that has no ethanol in it, already premixed with a little oil in it. I can see adding extra oil to the fuel to use it instead. Now granted you are paying a higher price for a quart of the stuff though. It costs around $5.95 a quart though. I had bought a couple of the fuel cans and used the fuel in my weedwacker. I wanted the fuel cans to use as containers for my Model diesel fuel.

I was thinking in worse case, if the NGH pump has problems, to just use a Perry Regulated Pump for gasoline myself.

Walbro actually makes the WT-499 carb which is designed for methanol or ethanol too.


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Old Mar 31, 2012, 07:30 AM
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Pleasant Valley Modelport
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When I flew ultralight planes we almost exclusively used Shell gas, the mid grade because after lots of testing the cylinder internals and plug were so low in deposits, the plug will always be that chockolate brown color it is supposed to be when the mixture is correct.

Sunoco is pretty good also, it seem to have a bit more kick per stroke, but the engine seems sort of rough from the kick. One guy flew Sunoco like that for years no problem, but Shell is overall preferred.
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Old Mar 31, 2012, 08:43 AM
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Canada, MB, Winnipeg
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Quote:
Originally Posted by earlwb View Post
That sure does look close like it ought to work for sure. But what I was commenting about was that our weed wacker and other utility engines run just fine using pump gasoline here in the USA. But the gasoline engines we buy for RC plane use seem to have problems using our pump gasoline. I have seen numerous guys have problems after a short while of usage. Other guys rebuilt their carbs or replaced the carbs and switched to Coleman Lantern Fuel instead and then they didn't have problems. So there must be something causing the problem with our USA gasolines.
Sorry about that I misunderstood. We have the same problem here with different brands having different additives.


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Originally Posted by earlwb View Post
I almost forgot about it, but Lowe's and Home Depot now sell quart cans of gasoline that has no ethanol in it, already premixed with a little oil in it. I can see adding extra oil to the fuel to use it instead. Now granted you are paying a higher price for a quart of the stuff though. It costs around $5.95 a quart though. I had bought a couple of the fuel cans and used the fuel in my weedwacker. I wanted the fuel cans to use as containers for my Model diesel fuel.
$5.95 a quart holly You must want those cans pretty bad. I pay $14 (well I use too) for a gallon of VP C12 racing fuel and it has 112 octane, no alcohol, has lead added, my snowmobiles, racecar, and weed wacker love it.


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Originally Posted by earlwb View Post
I was thinking in worse case, if the NGH pump has problems, to just use a Perry Regulated Pump for gasoline myself.
I think this would be the best long term answer to the NGH fuel delivery problem.

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Originally Posted by earlwb View Post
Walbro actually makes the WT-499 carb which is designed for methanol or ethanol too.
Cool, must be for use on Jr. dragsters.

Ray
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Old Mar 31, 2012, 10:42 AM
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When I was looking around for a suitable container for model diesel engine fuel, there just wasn't anything available. Then I discovered those gasoline containers, and they were pretty much perfect. Oh well. But I have accumulated a supply of Quart Davis Diesel Fuel containers now, so it isn't a problem anymore.

Anyway the gasoline smell, of this expensive non-alcohol gasoline in these containers, isn't annoying to me like the pump gasoline is down here that we have. I hate going to the gas station to refill the lawn mower fuel jug as the gasoline almost makes me nauseous with the odor or smell. I have to drive back home with all the windows open. So they are putting something in the gasoline that wasn't in it many years ago. I don't think it is a ethanol but something else.

It got me to thinking how just about all of the carbs on the RC gas engines are really made in China and maybe they haven't caught up on the specs of putting in the correct rubber parts so that the carbs aren't damaged by the gasoline. But the small utility engines we use have these parts in them as they still work just fine after a while. But maybe now they are putting in the right parts, as I hear about fewer people having the problem, but I don't know.
So I thought it safe to err on the side of using gasoline or naptha based fuel that doesn't have whatever it is in it that could be causing the problems.
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Old Mar 31, 2012, 04:39 PM
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United States, CA, Woodland
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Quote:
Originally Posted by Nav_Aids View Post
I was looking up some parts for another carb but came across a gasket kit that might work on the NGH fuel pump. I say might because the parts look correct but not having a NGH pump and the Walbro kit in my hands it is hard to say. The Walbro gasket/diaphram kit sells for $4.34, so it's not a major expense to try. Take a look at the pictures and let me know what you think. I think the Blue gasket would be either plastic or silicon and more compatible with glow fuel?

Ray
We'll find out. I just ordered one and will check it out & post results.
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Old Apr 01, 2012, 02:31 AM
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Motor set up on test stand just need fuel, so that will be tomorrow. Will keep everyone posted on 1/ if the motor starts. 2/ how it runs in. 3/ any problems.
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Old Apr 01, 2012, 09:36 AM
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Ok, for you performance folks, did you know that the Evolution Jett tuned muffler bolts right up to the NGH 9cc engine? yes it fits and it bolts right up Ok too. I would suggest milling out the exhaust inlet on the muffler to more smoothly match the exhaust outlet on the engine. But you would have the same problem on the Evo .60NX engine too, if you used it. So since it has been reviewed in several engine/airplane mgazine reviews already and the reviewers never mentioned it was a problem, maybe it isn't a problem.
Also note the blue anodizing on the muffler matches the NGH engine too.
Now as to whether you can get more power using one could be debatable as the Evo/Jett muffler is tuned to run in the 15,000 to 16,000 RPM range, which is a bit beyond the normal RPM range for the NGH 9cc gasoline engine.











Of course the NGH engine uses a 37.08mm hole spread for the muffler, So there are a lot of mufflers that would fit the engine too. One could use the MAC's one piece muffler 6590 or the Mac's Scotsman muffler 6594 or 6724 units too.
OS.40-.46 FX,SF, .46-.55 AX, .50 SX
Evolution .40NT & .46NT-NX & Trainer A, 60NX
ASP .46, GMS 2000 .40-.47
Irvine .40 & .46 (bolt through)
Magnum XLS.46
MECOA .40-.46, Royal .46
MDS .48 FS Pro (bolt through)
Rossi .45 (new)
Thunder Tiger .40 & .46 Pro
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Old Apr 01, 2012, 10:39 AM
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One of the big problems is, no one has been able to make a metering diaphram yet that's able to take the alcohol. The metal disc is a mass weight that's calibrated for the purpose of staying open a certain amount with the intake pulsations. The existing dia. has a ring formed outside the metal disc to allow flexing. May of you have seen what happens when, with old age, the dia. will shrink until it flattens right out. One reason is running the carb completely dry which causes it to shrink. Best to leave fuel in the carb to keep it wetted. It won't smell as it's sealed with the metering dia. closed and the inlet flapper valve in the fuel pump closed. Anyway a metering dia. would have to be made of Ceuloid or accrylic, with many of the rings like the one on the neoprene one to give enough flex. But this remains to be seen.

Gord.
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Old Apr 01, 2012, 11:20 AM
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Originally Posted by gravityking View Post
We'll find out. I just ordered one and will check it out & post results.
Alright, hopefully it works, this would provide cheap and easy parts supply. And then the truth will come out (Did NGH copy Walbro's design?). Yes! I have my own conspiracy theory.

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Originally Posted by brace View Post
Motor set up on test stand just need fuel, so that will be tomorrow. Will keep everyone posted on 1/ if the motor starts. 2/ how it runs in. 3/ any problems.
Good luck, hope it works out for you.

Quote:
Originally Posted by earlwb View Post
Ok, for you performance folks, did you know that the Evolution Jett tuned muffler bolts right up to the NGH 9cc engine? yes it fits and it bolts right up Ok too. I would suggest milling out the exhaust inlet on the muffler to more smoothly match the exhaust outlet on the engine. ........
That looks excellent Earl, now you just need to run it and see what type of performance you get.


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Originally Posted by flypaper 2 View Post
One of the big problems is, no one has been able to make a metering diaphram yet that's able to take the alcohol. The metal disc is a mass weight that's calibrated for the purpose of staying open a certain amount with the intake pulsations. The existing dia. has a ring formed outside the metal disc to allow flexing. May of you have seen what happens when, with old age, the dia. will shrink until it flattens right out. One reason is running the carb completely dry which causes it to shrink. Best to leave fuel in the carb to keep it wetted. It won't smell as it's sealed with the metering dia. closed and the inlet flapper valve in the fuel pump closed. Anyway a metering dia. would have to be made of Ceuloid or accrylic, with many of the rings like the one on the neoprene one to give enough flex. But this remains to be seen.

Gord.
I agree with you 100%. My weed wacker run perfect for 6 years and then one year I let the carb run dry before winter storage. Next spring the only way it would run was with full choke at idle. Stuck a diaphram kit in it and was back to normal.

Ray
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Old Apr 01, 2012, 09:48 PM
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I got to test run the engine today. I ran out of time for doing everything I wanted as I had fuel pump problems. At first it was getting the pump primed before it would work. That took longer than I expected. Once it got going it started working Ok. But when you bolt it to the back of the engine, the engine vibration and the heat the pump picks up off the engine causes it to start letting bubbles through. I suspect the gasoline is vaporizing inside the pump causing the bubbles. When I left the pump hanging and not bolted down so it was more isolated and lower down away from the engine more and less heat, then the bubbles pretty much all went away and it was much easier to adjust and run the engine.

The low speed needle was way way too rich. In order to start the engine, I had to close the main jet, and then start it so it was running off the prime and then quickly open up the main needle a couple of clicks, increase throttle a little and open the needle a little more, etc. Then adjust low speed and see how well it idled and adjust it some more. The low speed needle wound up going in several turns. I have it almost set now, but I need to tweak it a little more. I just ran out of time getting it dialed in.

With a 11x6 APC prop I was getting about 11,400 RPMs. I feel the engine might work better with a 11x7 prop, so I'll try it the next time I run the engine. Yeah I am running a MAC's One piece muffler made for a OS 55AX engine. It is bigger than the other Mac's mufflers that fit the NGH engine. In comparison one of my Fox .45 glow engines turns a 11x6 prop at about 12,600 rpms. So the performance of the NGH gas engine isn't bad at all, considering that gasoline doesn't produce the same power that glow fuel does.

I am also using a 1500mah NMH four cell battery pack to power the electronic ignition with. The 4.8v pack works quite well with the RCexl ignition unit.

I decided to use the gasoline you can buy at Lowes Home Improvement stores. It contains no ethanol ans comes in a 40:1 or 50:1 oil ratio. I added a couple of ounces of extra synthetic/mineral oil blend to the fuel. This fuel is great. No obnoxious nauseating smell that lingers around on everything it touches like you get with the horrid pump gasoline we have here in the USA. Our pump gas has ethanol in it and in some areas they have a lot of ethanol in the pump gasoline too. But the quart cans of gasoline they have at Lowes or Home Depot is great as you have no bad smells and it has no ethanol in it. Now this stuff is expensive, so if you are looking for a cheap fuel supply, then this stuff probably isn't for you then. Fortunately a quart should last quite a while as the gasoline engine consumes a lot less of the stuff in comparison to glow fuel.





With the fuel pump mounted like this, I got bubbles in the fuel line going from the pump to the engine.


With the fuel pump floating free and down low away from the engine and heat, almost no bubbles worth mentioning.


11,400 RPMs with the 11x6 APC prop.
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Old Apr 01, 2012, 09:59 PM
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Edit: Never mind, you already stated what kind of gas you used.

It seems like a pretty good engine. I noticed Agape Hobby has them in stock and listed for $200. It is very tempting.
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Old Apr 01, 2012, 11:54 PM
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Istanbul, Turkey
Joined Aug 2004
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Hi Earl, thank you for great effort and explanation here.It seems vibration is the main problem causing bubbles.So Michael must take some changes at instructions for installing fuel pump.I think some anti vibration damper can be used to mount the pump and should think as sensitive as a receiver.
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Old Apr 02, 2012, 05:35 AM
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Australia, NSW, Ashby
Joined Jul 2011
219 Posts
Damn! no start and flooded motor, will go back through the posts and ponder the problem. Will use the test on the pump and carb to determine if they are blocked open first.
A bit of a bother.
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