Model Technics Special Four Stroke 10% Glow Fuel

[Frank Skilbeck]

1 hour ago, Paul De Tourtoulon said:

As I just posted elsewhere,,,

 

First flights of the year for my Futura last week, carb stuck but with a bit of persuasion she was up in the air in no time, and yes a stream of unburned Castor oil down the bottom of the tail to clean off, it just proves that it did its job, lubricate the engine and not just burn off inside it.

Not really, what happens is some oil separates before the fuel is burnt, on a 2 stroke this is in the crankcase on a 4 stroke piston blow by on the compression stroke and makes.it's way to the crankshaft and valve. Once a certain amount has built up it then leaves either via the combustion chamber, 2stroke, or breather 4stroke. There are some videos on you tube of engines running with a clear back plate.

 

I still have to clean oil off my models, even though I'm running lower oil content synthetic, in all my engines, some 30+ years old.

[Jon H]

There is much talk about this oil 'burning off' business and its mostly nonsense. If the oil in the charge air burns off during combustion it dose not matter. As long as the oil film on the cylinder wall and other important components is ok, burning off the oil suspended in the fuel charge is actually a good thing as it stops it getting all over the place and oil additives can be used to help control combustion. Some early synthetic oils broke down even on the cylinder wall, so their bores got shredded. This is no longer the case. 

 

Also, if the castor didnt burn off it wouldnt smell, and wouldnt leave carbon all over the engine. so there is also that to consider. 

 

 

[Cuban8]

On 01/05/2023 at 07:27, David Davis 2 said:

Years ago I was given 5 litres of this fuel. I have never even opened it. I was going to use it in my Thunder Tiger 54FS in La Coupe Des Barons. However, there is a turquoise coloured label on the front which conveniently states that the oil content of the fuel is 9% castor and 9% EDL. This is much more castor than the 2% castor 15% ML70 Southern Modelcraft fuel which I'm currently using, and I don't fancy clogging up any of my engines with unburnt castor!

 

What would you do with this fuel? 😊

Try Optifuel's Laser 5 (Model Technics replacement) in your fourstrokes - I'm very impressed with its performance.

[David Davis 2]

2 hours ago, Cuban8 said:

Try Optifuel's Laser 5 (Model Technics replacement) in your fourstrokes - I'm very impressed with its performance.

Once I've used up all of my Southern Modelcraft fuel I will certainly buy some. I will use the low oil version in my newer Lasers. I don't think Id like to trust it in my OS or Thunder Tiger fourstrokes or even my old Lasers.

[aidan mcatamney]

I've been using Optifuel 12 in all my two and fourstrokes eversince it was invented and never have a problem.  

[Paul De Tourtoulon]

11 minutes ago, aidan mcatamney said:

I've been using Optifuel 12 in all my two and fourstrokes eversince it was invented and never have a problem.  

With 18% oil it should be,,,

[Albert Ace]

On 01/05/2023 at 15:04, Jonathan W said:

I can only agree. Talk of consigning a pefectly useable gallon of fuel to the bonfire is something of an over-reaction. No, it's not ideal to be running the Thunder Tiger on fuel with so much castor content, but it won't do any harm in the short term and then switch to a more modern recipe when it's been used up.

Oh dear...how things change. Castor does not harm an engine. What harms an engine is leaving it in there after the last run. 

All of my engines after thoroughly cleaned out and oiled  up after the last run.

After your engine is finished with, a short not run and shut down. Plug out and oiled ( 3 in 1), a good flicks and plug back in.

 

This should be fun..........

Albert

 

 

[Albert Ace]

Sorry, should have made clear I only run Glow engines.😁

Albert

[David Davis 2]

There was a time when people were moving away from castor based to synthetic based fuels when club colleagues would give me their remaining castor based fuels free, gratis and for nothing! Consequently I enjoyed flying my old Merco and Enya  powered models for free for a couple of years.

 

Since then I have acquired a number of four strokes including four brand new Lasers. For many years I have always used Southern Modelcraft fuel without a problem, 13% synthetic, 2% castor. I bought quite a large amount when I retired in 2015. Once current stocks are exhausted I will buy Optifuel, low oil for the new lasers and 15% synthetic for everything else.

 

PS. I have never found any fuel "too old" to be used but I will admit to chucking a cupful of petrol into the fuel during the Merco Days!

[Nigel R]

1 hour ago, Albert Ace said:

3 in 1),

3 in 1 turns solid with age. Ok for assembly if you're going to run the thing immediately after I guess. 

 

Not sure what recommendations for after run oil was last time this came up, air tool oil i think. 

[Chris Freeman 3]

Interesting comments here. I am about to finish a UC plane for my Grandson and have a Black widow 049 to power it. What oil would be best? I was thinking 10% klotz and 10% M with 20% nitro. I know the more nitro the better they run. Started the motor on a 15% oil and Nitro mix last evening and the little blighter makes a noise that takes you back many years!

[J D 8]

I run a couple of Cox engines, a 049 Thimble Drone and TD 051. The scream from the 051 as it fires up is scary when you have not done it for a while.

   Both are happy on 15% nitro car buggy fuel.

[Jon H]

On 07/05/2023 at 07:57, Albert Ace said:

Castor does not harm an engine

 

Yeaaa it kinda does. It will lacquer the innards, carbon the piston/valves and plug up the exhaust (4 stroke). 

 

The procedure you mention will not expel all of the castor from the engine, especially from the bottom end. its also a complete faff and simply isnt required if synthetic oil is used. As Nigel points out, 3in1 is really not good for use in engines for a variety of reasons. Slap it on your gate hinges by all means, but its no good for engines. 

[J D 8]

Power steering oil/fluid is a good after run preservative.

[Nigel R]

I've used gear oil, but you have to make sure you get the stuff without sulphur, grade GL-1 (says google) - otherwise it starts etching the innards, brass and bronze bits like bushes.

 

[Engine Doctor]

3 in 1 oil is a bad oil to use in our engines or anything else  other than door hinges or  squeaky garden gates.

I bought a box of engines most of them unused and boxed . However the owner with the best intentions had dosed all them with 3in1 oil and put them into plastic bags before storing them in the loft for a couple of years. The 3in1 had set just like clear varnish and had etched marks into the metal. As a reult all the unused engines cases were stained and looked dreadful. Thats when i invested in a beadblast cabinet to restore these engines. 

If you need to oil up an engine then air tool oil works very well , doesnt stain or etch marks into par, stays liquid and helps prevent any moisture damage.