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Old Oct 13, 2012, 03:29 PM
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USA, IN, Commiskey
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Question
Running methanol on spark ignition?

Do to the high cost of Nitro, I have been wanting to make the transition to gas. The problem with that is no one makes an engine in the .30-.50 size that is reliable out of the box. Conversion of one of my .50 glow engines to gas is the route I am looking at. I have found several people on the net that has done it with varying success.
It seems like the major problem doing this is the carbs on these engines are not made for the gas and no one makes a gas carb small enough. Methanol is cheap and available locally for me. Would a glow engine run on spark with a mixture of methanol and oil run with similar power as gas? I have not been able to find anyone doing this. It seems like it should work.
What do you guys that do this stuff all the time think?
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Old Oct 13, 2012, 03:36 PM
Complete RC Idiot Savant
The Netherlands
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It should typically run with more power compared to gas.
Gas has double the energetic value compared to methanol, but you can burn approximately 2.5 times the amount of methanol with the same amount of air (displacement volume).

You can hook a spark ignition to a glow engine no problem, provided you follow instructions that come with the ignition set

With a spark ignition, you can let go of Nitro, the engine does not need it anymore, because it is the spark that determines ignition timing, not Nitro content, motor temperature and plug grade. But take care that you use the same amount of oil and the same quality as you would with a glowplug.

Brgds, Bert
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Old Oct 13, 2012, 05:00 PM
I HATE GLOW PLUGS!
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^^^^ ALL OF THE ABOVE^^^^

I would like to also add:

In a 4-stroke R/C engine, CDI W/methanol produces about 6% more power than glow ignition on the same fuel. Gasoline produce about 15% less power than a glow ignition engine of the same displacement running metheanol. The net gain for CDI/methanol over CDI/gasoline in a given displacement engine is about 22%.

The CDI engine on methanol will run about 22% longer on a given fuel amount.

Reliable idle speed will be about 300 RPM lower on CDI.

One flip starts will be the norm & kick back will be a thing of the past.

Be for warned that if you are lazy in yiyr flipo technique you will get your knuckels beat up when the engine fires while turning it over slowly.

I have or I am in the process of converting all of my Saito engines to CDI.

Here is what is involved in a typical CDI conversion.
http://www.rcuniverse.com/forum/m_11...m.htm#11163452

A few videos of my CDI/glow fuel conversions.
FA180HC Video 0001 (4 min 36 sec)


Saito 300 Twin With C&H Ignition, 800 RPM Idle (8 min 9 sec)


You can get CDI system made specifically for your engine here.
http://ch-ignitions.com
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Old Oct 13, 2012, 05:36 PM
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Or just run the .30 to .50 glow engine on 80% methanol and 20% oil of your choice (castor/syth.) You may have to take out a shim or raise the compression somewhat. You can add 3% acetone to make it run smoother if you want to make a small batch to try. A lot of Europe doesn't bother with nitro at all, without going to spark. Four strokes, I can't say, it may be too hard to raise the compression.
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Old Oct 13, 2012, 06:11 PM
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[I] run my OS 300 twin on ignition with 80/20 glow fuel. It works excellently]
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Old Oct 13, 2012, 06:13 PM
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I generally run straight in my engines ... all of which are 4-strokes... all of which have standard compression.

The cost comes right down when you abandon nitromethane.


You can certainly run a glow engine on methanol and spark ignition. I've done it, successfully.

BUT I found that the setup was less reliable than running the same engine in its standard form, and using glow augmentation at low rpm. So, imo, there's no advantage to running methanol and spark ignition.

In fact, I find that glow augmentation, plus a fuel pump, gives phenomenal reliability ... I'd say that it's as good as a typical spark-ignition engine.

Some figures which I compiled a couple of years' back. Saito 1.80, with Perry Pump and glow augmentation at low rpm. The engine flew 32 hours in my Stampe, without a dead-stick. Then, it was removed from the model. Now, that's pretty good. Prior to the Saito, the model was fitted with a Zenoah 23, for some 150 + flying hours ... and I can assure you that there were a few dead-sticks in that time.
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Old Oct 13, 2012, 07:10 PM
I HATE GLOW PLUGS!
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United States, NY, St Lawrence
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Quote:
Originally Posted by bogbeagle View Post
I generally run straight in my engines ... all of which are 4-strokes... all of which have standard compression.

The cost comes right down when you abandon nitromethane.


You can certainly run a glow engine on methanol and spark ignition. I've done it, successfully.

BUT I found that the setup was less reliable than running the same engine in its standard form, and using glow augmentation at low rpm. So, imo, there's no advantage to running methanol and spark ignition.

In fact, I find that glow augmentation, plus a fuel pump, gives phenomenal reliability ... I'd say that it's as good as a typical spark-ignition engine.

Some figures which I compiled a couple of years' back. Saito 1.80, with Perry Pump and glow augmentation at low rpm. The engine flew 32 hours in my Stampe, without a dead-stick. Then, it was removed from the model. Now, that's pretty good. Prior to the Saito, the model was fitted with a Zenoah 23, for some 150 + flying hours ... and I can assure you that there were a few dead-sticks in that time.
I've been running C&H spark ignition for 15 years & have never had a reliability issue.

Perhaps it's not the spark ignition per see that was causing you reliability problems but the brand of spark ignition.

To say that a glow driver is more reliable than a properly set-up CDI seems a bit absurd to me.
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Old Oct 13, 2012, 09:42 PM
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Thanks for the replies. I was hoping to fine someone that had tried this. Great news to see more than one person has done it. We learn something all the time. I'm going to be using this in one of my helicopters. If it works out it will make the larger helicopters a lot more affordable to run. At 8 flights a gal. and $30 a gal. it sure is expensive flying.
I went to C&H web page and it said the CDI units are on order. Not sure what that means but will try and contact them and see what the time frame on getting one is. Will keep you all posted.
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Old Oct 14, 2012, 01:46 AM
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Absurd it may sound.

Them's the facts, as I found 'em. I didn't expect it either.

But, that's the thing about evidence ... it doesn't care about your preconceptions or bias.
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Old Oct 14, 2012, 05:22 AM
Complete RC Idiot Savant
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Quote:
Originally Posted by bogbeagle View Post
Absurd it may sound.

Them's the facts, as I found 'em. I didn't expect it either.

But, that's the thing about evidence ... it doesn't care about your preconceptions or bias.
Aehm.... that's not evidence.... that is only one engine, in one set-up.
If many people reported the same as you, it could be called a trend, still not evidence since you don't have info on the skills of those people.

More than one invention or piece of technology failed to become a success not because it was flawed, but because either people were not ready for it yet, or general skill levels were not high enough for the product to be used successfully

One of the best examples of "not the best technology, but more succesfull than its technologically better competitors" is everything microsoft makes, another is for example VHS video system being more succesfull than the technological and qualitative better V2000.

Fact is, that any engine with a spark ignition will run as reliable as that spark ignition. Usually a spark ignition is more reliable than a glow ignition....
there you have it....

My personal experience is that I can leave my OS FS91 Surpass III with spark ignition running at idle, and it will literally run until either battery or tank is empty.
It will do that over the full range of the low speed needle in which it will run. As long as there is an ignitable mixture, it will ignite and keep running.
At any other throttle setting it will run completely steady and it seems to deliver noticeable more power, on the same fuel I used to run it on as a glow engine.
The thing is: with glow, it would not run reliable on any other fuel, but with spark ignition, nitro content does not have any influence on its running anymore....

Brgds, Bert
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Old Oct 14, 2012, 06:45 AM
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"My personal experience is that I can leave my OS FS91 Surpass III with spark ignition running at idle, and it will literally run until either battery or tank is empty."



Ahem ... that's not evidence ... that is only one engine in one set-up.



Seriously, I think that the "legendary reliability" of petrol engines is a bit over-done. I've run many a sparkie ... and seen many hundreds fly ... dead-sticks are not uncommon.




(all of the above In My Opinion)
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Old Oct 14, 2012, 07:56 AM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
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Quote:
Originally Posted by mac2286 View Post
Thanks for the replies. I was hoping to fine someone that had tried this. Great news to see more than one person has done it. We learn something all the time. I'm going to be using this in one of my helicopters. If it works out it will make the larger helicopters a lot more affordable to run. At 8 flights a gal. and $30 a gal. it sure is expensive flying.
I went to C&H web page and it said the CDI units are on order. Not sure what that means but will try and contact them and see what the time frame on getting one is. Will keep you all posted.
If you call Adrian he will return your call. Right now, C&H is a 1 man operation & the systems are made to order W/your specifications.
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Old Oct 14, 2012, 07:57 AM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
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Quote:
Originally Posted by bogbeagle View Post
Absurd it may sound.

Them's the facts, as I found 'em. I didn't expect it either.

But, that's the thing about evidence ... it doesn't care about your preconceptions or bias.
Where di you find your "facts"?
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Old Oct 14, 2012, 08:21 AM
I HATE GLOW PLUGS!
SrTelemaster's Avatar
United States, NY, St Lawrence
Joined Feb 2012
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Quote:
Originally Posted by bogbeagle View Post
"My personal experience is that I can leave my OS FS91 Surpass III with spark ignition running at idle, and it will literally run until either battery or tank is empty."



Ahem ... that's not evidence ... that is only one engine in one set-up.



Seriously, I think that the "legendary reliability" of petrol engines is a bit over-done. I've run many a sparkie ... and seen many hundreds fly ... dead-sticks are not uncommon.




(all of the above In My Opinion)
According to your post, as far as CDI/metanol reliability, you were basing your "facts" on one Saito 180 engine set up for CDI & you still haven't revieled the brand of CDI that was employed..

Since 1997 I have run C&H CDI on 6 different Saito engines from an FA91S to an FA300TTDP & have NEVER had a dead stick or engine stoppage due to the CDI failing.

I tried on-bord glow, it will not provide the low dependable idle speed, increased fuel ecomnomy, increased power or the easy starting characteristics of CDI.

Not all petrol engines are CDI, none of them as far as I know are OEM C&H CDI.

RCXEL ignitions are a cheap Chinese made knock-off of the early C&H CDI & the RCEXL ignitions have shown to be a crap shoot as far as quality control.

The OEM Saito systems have a horrible reputation & when they are converted to C&H ignition W/a ZAMA or Walbro carburetor, the reliability issues vanish,

Many gasser engine users upgrade to CDI.

The FA180HC in my YT video will idle @ 1100 RPM until the tank runs dry too. My FA91S @ 1700, FA150A @ 1400, (2 of them) my stadard compression FA180 @ 1200 & my FA300TTDP will do the same.

Is it just a fluke that every Saito engine I testW/C&H CDI has a more reliable low speed idle, more power output, better fuel economy & better hand starting habits than they did W/glow ignition, onboard or not?

I did thourough test for all of the above parameters W/GI/methanol as well as CDI/methanol W/each of the above engines W/the exception of the FA300TTDP that was never even started on glow ignition

That's 6 different engine so far W/the same geat results.

How many engines have you tested W/CDI/methanol?
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Old Oct 14, 2012, 08:33 AM
I HATE GLOW PLUGS!
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United States, NY, St Lawrence
Joined Feb 2012
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Quote:
Originally Posted by Brutus1967 View Post
My personal experience is that I can leave my OS FS91 Surpass III with spark ignition running at idle, and it will literally run until either battery or tank is empty.
It will do that over the full range of the low speed needle in which it will run. As long as there is an ignitable mixture, it will ignite and keep running.
At any other throttle setting it will run completely steady and it seems to deliver noticeable more power, on the same fuel I used to run it on as a glow engine.
The thing is: with glow, it would not run reliable on any other fuel, but with spark ignition, nitro content does not have any influence on its running anymore....

Brgds, Bert
My tests have shown 5%-6% more power, 22%-23% longer run time @ WOT W/a given volume of fuel & 300 RPM lower reliable idle speed on average when converted to CDI W/the same fuel for both tests.

Also diminished is the need to fiddle W/the needle setting for atmospheric conditions.

The idea that somehow glow ignition is inherently more reliable than CDI is ludicrous. IMO
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