franchi

Hello All:

I have been using Diesels for a few years now and I need to know how much ether is optimum. I have been using 30% for years but I was told recently that I need at least 33%. I am looking for a mix that will produce an easy start for a sport engine by hand flipping. I may be kidding myself into thinking that I still have what it takes to provide the old Diesel Flick. Lol My mate who also flies Diesels complained that his shoulder was very painful after a day of flicking Diesels! We are both in our late 70's. Lol

How much is too much? I have seen suggestions as high as 50%. What is the downside of too much ether in a fuel? I run 25% oil, castor, in my fuels but I have been told that I am using too much oil for my old steel and cast iron engines as the kerosene will provide a bit of additional lube.

How do those FAI Team Race pitmen get those fast pit stops? I think that the planes are not more than one second in their hands! Yes, I will concede that their engines are perhaps a bit better than my Tigre and MVVS engines. Lol!

Be well,

Franchi

ffkiwi

I would not agonise over the difference between 30% and 33%-50% is way too high and only utilised for things like 1940s fixed compression diesels. The downside of too much ether is twofold-lack of power-as it is replacing a proportion of kerosene that could otherwise be there-and secondly cost-ether is by far the most expensive component! Recall if you will that Oliver brew-regarded as one of the 'classic' racing mixes for ferrous metallurgy-is 50% kero, 20% oil and the balance (nominally ~30%) ether -with your personal preferences of ignition additive-again classically- about 2.5% amyl nitrate. Kero is your FUEL component-thats where your BHP comes from-the other components are largely there for the ride-the oil for lubrication, the ether for ignition (and a bit of cooling).....the art comes in formulating a mix that balances the needs of your respective engine. I don't know where you got the idea that kerosene functions as a substitute lubricant from-not in this context certainly-in fact if you bother to read PAWs instructions they SPECIFICALLY caution against using fuels with high kerosene contents!

Sadly-as with most things in life-there is no 'one size fits all' in diesel-any more than in glow. What you can do is come up with a mix that suits the majority of your engines-and that's often simple trial and error! Personally I use only Modeltechnics D1000 and D2000 formulas-which meet virtully all my needs for running in, sport flying and competition use with plain bearing motors. Should i start using BB engines for competition i'll then use their D3000 formula as a start point.

As for you final query-well a simple answer would be one word: Practice!.......and a lot of it! A more appropriate answer is the engines are built to a standard not a price, using the best metallurgy and engineering fits currently achievable-are optimally adjusted by the pitman-and everything is adjustable-and repeatable-even to the amount of exhaust prime...

ChrisM
' ffkiwi'

franchi

Hi Chris:

Thanks for the great reply.

I did not suggest that kerosene is a substitute oil. It aids in lubrication. I have been told that the longer life of a Diesel engine vs. a gasoline engine is due to the fact that Diesel fuel has a bit of lubricity where the gasoline does not. Gasoline may be thought as a solvent and the kerosene a light lubricant. With the added lube properties provided via the kerosene is 20% oil adequate for a Diesel engine? What are your thoughts about using a 50-50 mix of castor and synthetic oil for lubrication? It has been suggested that this mix will lube well BUT keep your engine free from built up deposits. Of course, these deposits may be a good feature for lapped engines. I know that I have never burned up a glow engine when 100% castor was used for oil!!!!

You are correct that I have never read the PAW instructions. I have never seen a PAW engine in my life as they are not popular in this country. As a matter of fact, Diesel engines never caught on in this country. I have read and collected many formulae regarding fuel mixes for model Diesel engines. There is a vey wide range for the proportions of ingredients listed. My Diesel advisor is a chap who spent his younger life ,34, years living in the Ukraine where he used Diesel engines a great deal. A chap in our club who grew up in South Africa and I are the only Diesel aficionados in the area. We both find them enticing and fun to use. Anybody can run a glow engine but it takes a MAN to run a Diesel! Lol

Again thanks for taking the time to reply to my post.

Be well my friend,

Franchi

controlliner

Franchi, never worry about 33% castor oil making your engine carbon up. I have not seen many diesels made over dirty with carbon. With the needle and compression screw set at optimum, the engine will maintain it's cleanliness internally. Remember, Diesels run cooler than glows and therefor the castor is less like to carbon up.

1QwkSport2.5r

You will see more carbon (soot) from the kerosene than you will from the castor oil. If your kerosene is somewhat "dirty" (as in less refined than say Jet A), you will see more soot.

As for blending of oils - it is my opinion that any engine using a ferrous piston and liner should have only castor oil for lubrication. While synthetic oils tend to keep things "cleaner" internally, they do tend to prevent the castor varnish from forming on the piston which is important for sealing the piston within the liner. Better piston sealing = better power.

controlliner

The only problem I can see with Jet A 1 is it's low sulphur content. Sulphur aids in lubrication. My sister had a VW diesel and she used to put 1/2 a tank of Jet A 1 in the car. It wore out the fuel pump due to low sulphur content compared to D1 fuel. I believe the paraffin we use in our model diesels has more sulphur than D1.

1QwkSport2.5r

I tried Jet A because some other diesel guys said it burned cleaner and made a little more power than regular kerosene. I found it ran well although not any cleaner and not any more power than regular K1 Kerosene (sold for home heating). Jet A is refined more and as such probably has less of some compounds than kerosene or regular diesel fuels. Jet A is clear as water and the kerosene I'd been using has a slight tan color to it.

greggles47

I'm not too sure that there's any real comparison between auto and model diesel operation. One of the main advantages of Jet A1 is that its spec is consistent whereas other keros are not controlled. Hence you can get a great range of effectiveness from good to downright poor. Oils are equally important, good quality castor is an essential for me, but if I was going to run synthetic I'd be checking what the F2C teams used.

controlliner

Motul synthetic is one of the best. I can't get it here in Canada.

1QwkSport2.5r

That stuff is also $80USD per gallon too. It is a PAG type synthetic, so it's along the same lines as Klotz and Cool Power oil. The best oils are ester based, but they're quite expensive as well.

For diesel use, I don't think anything beats castor though.

fiery

My Feedback: (2)

Anyone tried Maxima 927 castor-base oil? Kart and Motorcycle shops sell it.

fiery

My Feedback: (2)

Has anyone any experience with Maxima 927 castor based oil (as sold by Kart and Motorcycle shops)?

ffkiwi

I believe the UK's Dave Clarkson and Ed Needham were quite successful in diesel Goodyear using Castrol A927 which is probably an earlier version of the Maxima 927 in their fuel mix-but they were particularly meticulous in their setting up and equipment. Even back then they winced at the price of the stuff....! Whether it has anything to offer general sport diesel users is debatable.

ChrisM
'ffkiwi'

PS Personally I found Castrol MSSR a great synthetic lube-but AFAIK it was only ever available in Australia and NZ (and was indeed developed down here)

ffkiwi

Franchi-I find some of your comment odd-PAW engines are the most widely sold diesels in the US-and have had very good support and promotion by the US agent Eric Clutton. I can accept that you have not personally handled one-but your statement that they are not popular in the US simply doesn't add up-as any routine persusal of Ebay will confirm.I am aware that diesels have only minority takeup by modellers in the US-you might also reflect that this is not the case in other traditional modelling countries-by implication means those of us elsewhere may well have a lot more experience with them. PAW are simply the largest diesel manufacturer in the world-both numerically and in terms of range-not only that-they've been in business making diesels for well over 60 years I would seriously suggest that if they specifically caution against excess kerosene /paraffin)-they have a damn good reason for making such a statement! In any case-the only valid comparison is with glow engines-which use lubricant in a similar proportion. We have long since surpassed classical 'model' gas engines both technically and metallurgically (ie those using a 3/1 or 4/1 petroil mix)-and modern model gas engines are using much lower lubrication levels as well as often having structural refinements-needle bearing big ends for example-which are absent in our model diesels.

20% lubricant is generally considered a good safe level for twin BB engines-plain bearing ones are generally considered better off on 25%. It need not be overstated that 1/3 lube is excessive....but 1/3-1/3-1/3 mix has the advantage of being easy to mix-and no model engine ever suffered harm from too much lubricant-whereas the converse does not hold! I know of a few people who are using as little as 15% lube-equally i know these people have a lot of experience, know their engines inside out-and are very good at setting them. [and these people are generally flying team race and using engines that are cutting edge metallurgy-a lot more exotic than your traditional steel cylinder-cast iron piston, unbushed rod and plain crankshaft setup...] Horses for courses as they say...!

ChrisM
'ffkiwi'

qazimoto

My Feedback: (1)

Yes, I have most of a US Quart container down in the shed. It was slightly more expensive than other blended castor based oils but wasn't what I'd call expensive. I've been using it in a PAW recommended fuel of 15% oil, 35% Ether and the rest Kero in my PAW 15 TBR GTS2 Diesels for speed limited Goodyear racing. It's a US product with no obvious connection with Castrol. My assessment was that it was a perfectly good oil, as effective as the now unobtainable Castrol M. Probably works much better in F2C fuels where they go down to 5% oil.

Most of the diesel flyers in my club have gone over to Klotz Benol, a blended castor oil. Seems to work fine and it's available in five litre containers at a better price than the Maxima product.

Lately I've been using real castor from "Kombatkid" in Victoria. It's probably Veterinary Castor. For my needs it works just as well as the Maxima or Benol as well at a better price. I've been using it at 20% in just about everything besides the hot PAWS and Nelsons which run much better on the lower oil fuels.