I just realized I didn't answer your actual question. See this thread: http://www.rcuniverse.com/forum/m_80..._1/key_/tm.htm

AV8TOR

Currently I'm running the ST 3000 on E85 ethanol/gasoline and the CH ignition. Had to lean the needles considerably from the settings for methanol/nitro. Using 12% oil in this mix. Getting about the same power on the E85 as I did on methanol. Might try it on glow with a hot plug.


CR

Well, the above is not true. As I stated before I used 16:1 gasil mix. That's 6.25% oil. There's oil in the gasoline, y'see?

C'mon guys, get off the needle bearing kick!

Oh, and for the guy from Oz, E85 is indeed 85% ethanol and 15% petrol.

CR

OOPS! Double posted. Sorry! CR

Av8tor1977 is very experienced with actual modification of many engines

Hi ,
Thanks for your replies.
Av8tor, I looked into that excellent thread of yours but it seems to be only on Gas to glow. As you know, I am interested in the glow to gas conversion. The St 4500 is a 2stroke glo engine and I am wondering if the use of the E85 and an F plug is all that is needed to operate this engine efficiently using 12% oil.

( My only source of E85 is 500 Km. away otherwise I would try it myself ! )

Many thanks,
Merlin.

the concept is the same, it's just the fuel mix. what you need is a fuel mix that will ignite the glow plug. If the supertigre has bushings on the crankshaft then you will have to run more oil than the guys running the mix in the weedeater type engines. The fuel mix they are running on is 2 parts premium gasoline to one part 10% nitro 10% oil glow fuel. You could probably run on that mix with a little extra oil or modify the ratios in other ways...

So am I. And your point is?

In any event, I only write about the things I've done and my experiences with them. I leave speculation to others. When I know, through experience, that someone else's speculations are not true, I'm liable to say so.

BTW, Y8, I'm older than you are, unfortunately.

CR

In my experience, you can run less oil in gasoline without converting to needle bearings. Consider: I ran the Saito on a 16:1 gas to oil mix. 16:1 gas to oil = 1/16 oil = 6.25% oil. What must be understood is that the gasoline contains oil, so you can lower the oil content in the mix.
CR

Edited for typo.

wait a sec...
Are folks saying they are using Ethanol (e85) instead of Methanol to fire a glow plug?

You need to read around some.

The glow plugs don't work the best in the world with E85.

Some are saying that cold plugs work better and some are using heaters

Some are using spark

Some are using mixtures of regular glow fuel and E85/with synthetic oil and or castor

And so am I. Your point is?

CR

Uh, not exactly. At least one guy said he was using E85 fuel fired by a glow plug.

CR

There have been a few here that have had various levels of success using ethanol based fuel and a glow plug. However when I tried it several years ago when we were first sorting out the Gas/Glow system, I didn't have much luck. The engine misfired badly on E-85 based fuel.

AV8TOR

Want to elaborate on that? Which engine? What was it's compression ratio? Which plugs did you try? What lubricant and what percentage of lube? Which props? Please elucidate.

CR

I tried it on some Echo 21 to 25cc engines, and some Homelite 25 and 30cc engines, with varying compression ratios, various glow plugs, with full time glow power and without, and various mixtures of ethanol based fuels. For me, the results were unsatisfactory. As I mentioned, others here have had some varying degrees of success, and a search will bring up their threads. The glow plug really needs methanol for proper catalytic reaction with the platinum in the plug. OS Engines briefly advertised that they were going to release some engine(s) that were set up for ethanol fuels, but I haven't heard any more news, nor seen any of the engines yet. Perhaps they found it wasn't feasible, I don't know.

I settled on our present "Gas/Glow" system (using methanol based fuel and gasoline), as being the best all around compromise, and they work very well. Good luck on any experiments with ethanol and glow plugs, and please keep us updated on your progress.

AV8TOR

woah, the thread is still here [8D]

I just tested a ST gs40 on 5:1 E85 and Castor (sounds like a 16% oil plan).
Stage1 of the tests was to mix E85 with some oils, and see what stayed and what separated,
castor stayed but ElectroluxPoulanWeedie 2stk didnt, and wesson oil from the kitchen didnt
It was a new engine, with a few tanks of regular break-in on glow.
The E85Castor started right up, and ran unpowered-glowplug while we tweeked the needle,
but at WOT it heated up after a min, got surgey, and shut down.
(had 'smoke' the whole time, the laymans 'not too lean' indicator)

After a cooling, we tried again with less throttle, and richer.
We tuned it off the 14k (10x6MAS) down to 11k+, and it ran surgey.
We the throttled it down to about 2/3 open, and was still 10k-11k.
Idle was smooth as glass, nice & low, but not superlow.
Transition was... well, it wasnt.
It came off idle and surged around 8k, then eventually got back up to 11k after like 30 seconds

We are guessing the rpm was changing as the engine temp changed... just wild guess though



So
How do I know if I was firing the un-lit-glow off E85, or was dieseling after the lit-glow start?
How can I cool this down... more oil? Less prop? Run it only in the winter?




Note/warning:
Seems even the e85 diluted some,
the gasoline in the E85 did attack my fuel syringe black piston.

Did you tell us what plug you were using?

Due to the different air/fuel ratio required for the E85 mixture, your mid range will probably be fouled up?

The ST gs40 came with a plug, was using that

I first benched the engine on 15% glow and got an offpeak tune of 14k to compare tests to.
I then guessed a half turn richer as a starting point for the 5:1 E85Castor
(if I was gonna be wrong, I'd rather not be too lean)
It fired right up and we started leaning it up to a smokey 14k
... we stepped back to enjoy the success and it died (wicked hot)

Come to think of it, we did NOTHING to the low end needle at all,
and it idled like a kitten

I'm not trying to actually solve your problem or tell you what to do.

Just curious as I'm interested in E85

If the engine stopped hot, how did the piston look from the exhaust port?

Is it a possibility that the fire went out because of a lack of methanol for the catalytic reaction and with the sudden stoppage, there was a lot of heat to suddenly dissipate because no wind was blowing over the fins? The engine would smoke and smell which to the senses means hot?

There's been a lot of discussion about plugs, hot ones, cold ones, and four stroke ones?

I didnt look into the cylinder after it stopped hot.
We did turn it over a few times to make sure it wasnt seizing/cooked.
The engine was too new, there wasnt any smoking off the hot engine... but that might be cause it was really clean. When I said it was a smokey run, I meant the exhaust had that 'smoke' we want to see in a 2strk.

I do find it interesting that I had no methanol in the fuel, but it ran with the plug unlit.
Wonder how I can find out what kind of plug the ST gs40 came with

If it was shiny and looked like a OS plug, it was a Tower plug

If it was black, it is some Chinese off brand

Its a shiney plug.
The paperwork in the box makes no mention as to any specific plug info beyond the obvious RC Long. Looking at the plug, there is no idle bar

It is likely a Tower plug made by OS.

They used to be like the old OS A3 but I don't know any more.