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-   -   Testing for ether content? (https://www.rcuniverse.com/forum/everything-diesel-87/11700220-testing-ether-content.html)

franchi 06-25-2022 02:22 PM

Testing for ether content?
 
Hi:

Today, I was testing for ether content by the following method.

I expose a given amount of fuel to the Summer Sun, 91 degrees for an hour and measure again to determine the amount of mix that disappeared. I assume that what is missing is the ether contention . Is this method an accurate way to determine the total ether percentage in a mix?

Tia,

Franchi


1967brutus 06-26-2022 01:25 AM

Not accurate, but a good, probably useable approximation.
These things are always a bit tricky because not ALL ether evaporates at 91 degrees, and some of the Kero will evaporate as well (but that is marginal).

Boiling point of Ether is 95F, so if you carefully (repeat: VERY CAREFULLY)) heat up to 100F and maintain that temperature for a while, that would be more accurate but it is a pretty risky operation as the vapours are not only extremely flammable but also have an anaesthetic effect on humans. So I would strictly recommend NOT to do that unless you have lab-quality equipment AND the knowledge and training to use such equipment. Ether vapours are not something you want to mess around with.

franchi 06-26-2022 08:27 AM

Hi Brutus:

Thanks for the reply.

I am having a difficult time starting my Diesels. I suspect that 25% ether maybe to blame. Due to the high heat, I am hesitant to test my fuels. I will add some ether to a mix to see if it improves my starting ability.

My flying Mate flew his Mills .55cc on 1-1-1 mix and it started on the third flip after one choked flip. I failed to get my MVVS 2.5 started via an electric starter.

Stay well,

Franchi

1967brutus 06-26-2022 10:02 AM

I am not knowledgable enough to say whether 25% Ether is enough, or the cause of your problem, but AFAIK most fuels contain about 30%.
Anybody more knowledgable, please chime in...

1QwkSport2.5r 06-27-2022 03:25 PM

Small diesels need more ether. 25% is too low for most diesels. 30% and up is better with the little ones needing 35-40% ether. 20-25% castor oil, 2-3% nitrate ignition improver, and balance kerosene.

If your diesel doesn’t start and your priming regimen is 100% spot on, then your fuel needs to be tweaked. Start with 35% ether and see if that improves starting.

I would encourage you to do some reading and research to see what fuel your engines need.

franchi 06-27-2022 04:19 PM

Hi, Thanks for the prompt reply.

I have read quite a bit re. Diesel fuel. The instructions that accompanied my MVVS 2cc diesel stated that the ether content should be 45%. I have been running 30-35% ether in my other diesels. Perhaps I should increase the ether content. I am curious to see if 45% ether will permit me to hand start my Diesels.

My flying mate uses a 1-1-1 mix and he has no problem starting his engines by hand. Another thing to try! His ED Racer started on six flips. He purchased this engine circa 1955. He started his Russian Mills .55 on three flips with this mix. Can one say,”Hello 1-1-1 mix?”

Be well,

Frank




1QwkSport2.5r 07-07-2022 02:50 AM

That 1/1/1 fuel mixture is the old mix for the old lapped and bushed diesels. If you run those engines, then use that mix. Otherwise, use a fuel more prudent for modern engines if that’s what you have. All of my diesels are converted glow units. I know, not true diesels in the best sense, but they run and make good power. With good piston sealing (mechanical condition) and a good prime, a basic fuel blend of 30-35% ether, 20-25% castor, 2% Amsoil Cetane Boost, and balance kerosene will work for most engines giving single digit hand-flip starts. Antique/vintage ferrous engines should have/need the vintage 1/1/1 fuel brew.

The MVVS may need more ether because of the conrod. More ether is easier to combust with a lower compression setting. High compression settings are hard on conrods. If the rod is the weak point of the engine, use what the manufacturer says for fuel. Most of the time, diesel manufacturers know what their engines need to run correctly.

franchi 07-07-2022 05:59 AM

Hi:

Thanks for the reply!

I have been using a mix of 35% ether, 25% castor oil ,2% Amsoil centane booster in my Diesels. However, I just found that MVVS suggests a mix of 45% ether, 25% castor oil and the remainder kero. To this I will add 2% DII. I will try this as soon as possible.

My mate used a 1-1-1 mix in his Russian clone of a Mills .33cc and it started in three flicks after two choked turns! What a sweet running engine!

Should an engine start by using the existing settings from the previous good run? I see people increasing the compression and making the fuel a bit richer for cold restarts. I have tried this to no avail. Must continue testing until I get good results. Of course I could avoid all of these pitfalls if I would use glow engines but I would miss the aroma of the Diesel. Lol.

Who did your conversions? I had little satisfaction with DDD conversions!

Stay well,

Frank

1QwkSport2.5r 07-07-2022 06:18 AM

Frank - you can sometimes get an engine to start on the previous “run” setting if it’s still warm. If cold, an electric starter will get it started, but if I do this. I let the engine draw fuel to the carb. Just an insurance policy from hydraulic lock. If I manually prime it, I hand flip it. If you hand flip only, usually two flips after reaches the carb is a wet enough prime to start it (at WOT and carb choke plugged). Usually 1/4-1/2 turn higher for compression from the run setting will work.

I would try the 35% ether on the MVVS and see how it runs; it might be enough.

My conversion heads are all from DDD. ST .45, .51, OS .25FSR, K&B .20/.28, .45 are what I have right now.

atesus 07-27-2022 11:04 AM


Originally Posted by franchi (Post 12732687)
Hi:

Today, I was testing for ether content by the following method.

I expose a given amount of fuel to the Summer Sun, 91 degrees for an hour and measure again to determine the amount of mix that disappeared. I assume that what is missing is the ether contention . Is this method an accurate way to determine the total ether percentage in a mix?

Tia,

Franchi

I realize and hope that you probably solved the fuel problem by now, but I wanted to give some feedback on the original question.

I pour some unknown diesel fuel into a 10cc cylinder, 2cc or so fuel is good to make a fairly accurate assessment. I wait for 2 days for good measure, at which time all of the ether is gone and the castor oil is separated from kerosene and all three components can be measured. I'm not sure how ignition improver affects this but it is in very small amounts so it really is not an important error source. In my experience, 1 hour would be too short for all the ether to evaporate even in hot weather.

As for fuel mix, I use 40% ether, 28% lamp oil, 30% castor oil and 2% Amsoil for all engines below 2cc, except for my Letmo 0.6cc replica which won't run reliably with anything other than 70% ether and 30% mineral oil :D.

franchi 07-27-2022 12:20 PM

Hi Atesus:

Thanks for the reply.

I do not know if I have solved my fuel problens yet but when the weather cools, I will continue my quest.

The instructions that accompanied my MVVS 2.0 Diesel called fo an ether content of 40%. I am using a 35% ether content mix now. I am curious to see if an additional 5% ether will make any positive changes.

For some perhaps perverse reason, I have been drawn to the dark side of Diesels.

Stay well,

Frank


greggles47 07-30-2022 03:01 AM

Franchi,
If i'm unsure of the remaining ether content of my fuel, I use the method outlined by atesus, a day or so does the tricI like to use 100ml in a graduated vessel, to make the maths easier

I generally use 2 Fuel mixtures, for ball raced engines I use what is commonly known in Aus and UK as the Olly brew, being the mixture recommended for use in Oliver engines. That mix is 20% Castor Oil, 30%Ether and 50% Kero, to which DII is added in whatever weather conditions and intended useage determine.
For plain bearing engines I use 25% Castor Oil. 30% Ether and 45% Kero, 1.5% DII is added after mixing.

I NEVER use an electric starter on any of my diesels. They generally start on the last running setting, but may need a bit of running to warm up.

atesus 08-05-2022 11:56 PM


Originally Posted by franchi (Post 12737234)
Hi Atesus:
For some perhaps perverse reason, I have been drawn to the dark side of Diesels.
Frank

Same here! I had no interest whatsoever in wet power but once I stumbled upon a diesel, I got hooked. No idea why, ether fumes maybe :)


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