Castor or Synthetic? (Full Version)

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Da R/Cer -> Castor or Synthetic? (9/20/2003 6:51:49 AM)

Does anybody know if i should use castor or syn .
Also can any body tell me where i can get castor or methanol in Aus.
Last but not least does any body know if 2 stroke oil like Castrol 2t will
mix with methanol.



SpaceCase -> RE: Castor or Synthetic? (9/20/2003 4:07:47 PM)

Castor AND synthetic I think it is. You might want to look into a mix of both. Look under reipes, homebrew under a search here. should find a few things



Da R/Cer -> RE: Castor or Synthetic? (9/21/2003 6:02:19 AM)

Oh! so castor and syn.

Thanks alot!



mutare23 -> RE: Castor or Synthetic? (9/21/2003 2:11:10 PM)

In the old days, I used castor exclusively using the old addige if it aint broke dont fix it.

Then came comopetition pattern flying and I found out it was broke and changed all of my engines to Coolpower synthetic.

20% coolpower oil coversMOST modelling requirements and has never casued me any problems running nitro up to 35% in the old OS 120 supercharged engine.

Some will say add 2% castor to your mix, but I havent every found the need for it

Cheers

Phil



Da R/Cer -> RE: Castor or Synthetic? (9/22/2003 9:46:12 AM)

thanks alot .

So that means i can use stuff like Mobil 1's 5w-40.
Ive got heaps of that!



russellk -> RE: Castor or Synthetic? (9/22/2003 11:26:24 AM)

I'm not sure what is in Mobil 1's 5w-40, but I doubt it will mix with methanol - few oils designed for petrol engines do.

Seeing as you're in Syd, give John a call on 9607 9989 - he's an agent for AT Racing in Liverpool - he sells Coogee methanol 20L for $35, Klotz KL200 synthetic oil $14.30/litre and nitro for $15/litre.

His castor oil is a bit expensive - $19 for 500ml. You're better off going to a Castrol dealer and getting "Castrol M" - about $60 for 4L. Another option for methanol is Shell "Racing A" which has about 3% acetone, but at $52 for 20L it's more expensive than Coogee methanol, which has no additives (that I know of).

As for mixes, you can try 15% syn + 3% castor which works OK, the castor is meant to protect your engine if you ever have a lean (=hot) run - the castor will hang around at high temperatures after the synthetic has broken down. Then again, a lot of people run full synthetic and have no problems. I've seen total oil percentages from 15% to 25% - you're probably safest choosing somewhere in the middle of that - maybe 18-20% total oil.

Hope that helps!

Russell.



downunder -> RE: Castor or Synthetic? (9/22/2003 3:43:38 PM)

Leave the Mobil 1 to Peter Brock...it won't mix with methanol. Shell A is more expensive because you have to buy it in their own new drum (means you have to pay for the drum). BP or Caltex depots have methanol in bulk so take whatever size container you like.



sigrun -> RE: Castor or Synthetic? (9/22/2003 11:44:26 PM)

quote:

Shell A is more expensive because you have to buy it in their own new drum (means you have to pay for the drum)


Shell Racing A is that much more expensive because it is Shell Racing A and a Shell pricing policy tiered product. ie: Segmentally marketed to a particular demographic and maximimum demand pricepoint Shell consider the product will bear. The new drum has nothing to do with the price differential between it and Shell unadulterated methanol. Shell also sell 20 litre pre-packaged only methanol for $47.

The local Shell depot (Brisbane) won't dispense methanol in any form other than pre-packaged in either 20 and 200 litre drums. My recent enquiries revealed BP have since proprietarily renamed their 20 litre methanol product and adopted similar pricing policies. I suspect if they haven't already, Caltex will shortly catch up with the McMarketing practice by now as well. Not surprising given insurance premiums and the litigious era in which we now live. Ask around in your club/city todetermine what the current status quo is.

Best bet or cheap methanol has always been your local club or a sympathetic hobby shop which still buy-in 200 litre drums and sub-dispense, or will until a litigant or insurance catches up with them, delete as ap,icable whiever occurs first. Going price for that bring your own drum source currently averages between $25 and $30 for 20 litres.

Methanol requires an alcohol miscible oil. Castor can be the cheapest, but its price varies widely.



Da R/Cer -> RE: Castor or Synthetic? (9/23/2003 9:24:25 AM)

Thanks russellk.

Does John like have his own shop or something because if you were wondering i live in liverpơol.

Any of you guys know if i could use methylated spirits.
Also i just wanted to know if i could use normal unleaded petrol to run
these cars because i have some friends that do and they said it works great.



russellk -> RE: Castor or Synthetic? (9/23/2003 5:47:37 PM)


I haven't been to see John yet - he's at Unit 22 264-272 Hockston Park Road Liverpool - I don't know the name of his business, but from the sound of the address it sounds like a proper shopfront. I'm planning to pick up fuel next time I'm coming back from Sydney. His prices are a lot better option than Shell and the local hobby shop, but it's too expensive to freight, so picking it up in person is the only option.

You can't use metho - there is a catalytic reaction with the platinum in the glow plug and the methanol that makes the fuel ignite - along with pressure and heat.

I've heard of some people cutting in a small percentage of petrol for various reasons, but have never tried it.

As for straight unleaded, I think either your mates are taking the piss, or they've flogged the engine out of their parents' whipper snipper. Glow engines operate on a completely different principle to spark engines.




russellk -> RE: Castor or Synthetic? (9/23/2003 6:02:00 PM)


By the way, you might like to check out:

http://www.geistware.com/rcmodeling/glowpower/index.htm

it's a good summary of the basics of R/C fuels, and also has a cool table of all the different fuels people like to throw into their mixes.



Da R/Cer -> RE: Castor or Synthetic? (9/24/2003 11:23:23 AM)

I ve just checked it out it was sick!

Once again Thanks.

Next question

Is Nitro good for your engine ,what does it do?



mutare23 -> RE: Castor or Synthetic? (9/24/2003 12:56:14 PM)

This might be a good one for Downunder, but for what its worth; I understand that Nitro is like a concentrated form of liquid oxygen that enhances the power on each stroke as the nitro and the methanol can achieve a higher power value per each unit of measure compared to fuels without nitro.

I'll be interested to see some of the other replies

Cheers

Phil



eddiemans -> RE: Castor or Synthetic? (9/24/2003 2:11:03 PM)

Another option for synthetic oil is "Penrite TS40C "
It is a high quality oil suitable for high speed, high stress 2 stroke engines & will mix with methanol. Recomended oil for ultra-light aircraft & competition 2 strokes.



downunder -> RE: Castor or Synthetic? (9/25/2003 8:53:12 AM)

:D Well I don't know if it's a good one for me or not but I'll give it a shot.

Nitro is neither good or bad for an engine so long as it's used properly (or my preference, not used at all :) ). Nitro is supposed to release extra oxygen for the methanol to burn but I have a hard time believing this because nitro is a fuel all by itself (as in drag race engines that used to burn 100% nitro) but they still need air to operate.

However, nitro is a poor fuel compared to methanol in the same way that methanol is a poor fuel compared to petrol. A good fuel is one that has a lot of heat energy (per pound, kilo, ounce, whatever) that gets released when combined with the right amount of oxygen. Now the thing is that any engine can only draw in a fixed amount of air (oxygen) each cycle so you have to regulate the amount of fuel that gets mixed with this air. Too much fuel and there's no more oxygen to be combined with it so it's too rich and raw fuel gets spat out the exhaust, we tune the needle to get just the right amount of fuel.

So the question now becomes if nitro is such a bad fuel (low heat energy) then how come we get more power from it?

Well without getting all techo it comes down to how much of each different fuel you have to mix with that fixed amount of air each cycle. Take petrol compared to methanol. Even though methanol is a poor fuel you have to mix a lot more of it with that air for it all to burn. And a lot more means more weight (mass) of fuel each time the engine fires. In the case of methanol the extra mass each cycle more than makes up for the fact that it's not a good fuel. In rough figures, methanol has only got about half the heat energy of petrol but when you burn 3 times as much then you come out on top power wise.

Nitro though is even more extreme than this. You can dump absolutely HUGE amounts of nitro into the air drawn in by the engine and still have it burn completely (come to think of it, this is an indication that it could be releasing some oxygen). The heat energy in nitro is only half of what's in methanol, or one quarter of petrol, (that's why it's such a poor fuel) but it'll still burn even if you dumped 10 times the amount that you could get away with in methanol (that's what they do in drag racers).

So this explains why your needle valve has to be screwed out and your fuel consumption goes up when you add nitro to the mix. You have to flow a lot more fuel past the needle valve to get it to mix properly with that same amount of air. But you get more power. Is it worth it? Well that all depends on what you're looking for.

And where did I learn all this? Well originally it was an article written for our club newsletter that long ago I put up on the web page I do for the club at http://www.holdfastmac.com.au/techfuels.html although I modified the original article a bit to add a few things.



mutare23 -> RE: Castor or Synthetic? (9/26/2003 4:17:59 AM)

I knew you would be interesting downunder

Why then, is nitro a real benefit in small doses for the inproved idle performance of our engines?

Cheers

Phil



Da R/Cer -> RE: Castor or Synthetic? (9/26/2003 10:47:09 AM)

That what heaps useful!

Thanks alot.

Does any body know where i can get Penrite TS40C and how much it cost in
Aus.



eddiemans -> RE: Castor or Synthetic? (9/26/2003 1:33:56 PM)

PENRITE TS40C

This oil should be available at most large auto accessory shops or good motorbike shops. Go-kart shops should also be able to get it for you. Not sure of costs as I'm not at work at the moment but get what you pay for. If you can't find it, let me know & I will look up your local distributor for you.



Da R/Cer -> RE: Castor or Synthetic? (9/27/2003 6:17:58 AM)

OK

Thanks!



eddiemans -> RE: Castor or Synthetic? (9/27/2003 9:30:28 AM)

[:'(]

Sorry guys, I gave you some mis-information on the PENRITE TS40C oil.
Penrite's tech dept said it would mix with methanol with a good deal of mixing/shaking.
What they didn't say was that it seperates again on standing. Please do not use until further investigation!



downunder -> RE: Castor or Synthetic? (9/28/2003 2:49:51 AM)

quote:

ORIGINAL: mutare23

Why then, is nitro a real benefit in small doses for the inproved idle performance of our engines?

I think it comes down to the low compressions normally used. Nitro by itself can only handle about 6.5:1 before it goes BANG instead of puffff (techo terms for detonation and combustion :D ) so the compression pressures at idle are more in the range where nitro burns cleanly but methanol has a harder time of it.

I modified an Enya 60X to take full advantage of zero nitro fuel by raising the compression to 13.5:1 and the affect on the idle was amazing. I had to lean it out considerably which indicated that the combustion was much more efficient. But it then idled slower and very smoothly although there was nothing wrong with how it idled when standard.



petocar -> RE: Castor or Synthetic? (9/30/2003 5:46:38 AM)

hi im just wanting to know about whats is the real difference between castor and syn,
also im owndering about 2 stroke mower oil would that work same as castor?
ty

Chief



downunder -> RE: Castor or Synthetic? (9/30/2003 2:53:22 PM)

There's 4 main differences between castor and synthetics that I can think of off hand.

Castor has a higher flash point than synthetics with the exception of the turbine oils. That just means that castor will still be an oil when the synthetics are burning.

When synthetics get too hot they break down into the chemicals that were used to make them. Castor breaks down into other lubricants as the temp rises until it reaches it's final lubricant which everyone calls varnish.

Castor is what you might call an extreme pressure lube because it likes to stick to metal and resists being squeezed out. This is handy in highly stressed areas like both ends of the conrod, particularly the small end where there's very little rotation keeping the oil spread over it.

Castor will carbon up the piston crown and combustion chamber over time but synthetics run very clean.

Forget about mower oil...it's only designed to mix with petrol. For our use there's only a few synthetics that are known to work OK and it's best to get them from the hobby shop or a Go Kart shop if you know exactly what you're after. I have to admit I've got no idea what synthetics are sold here in Oz because I've never used them except for turbine oil.



Pjtg0707 -> RE: Castor or Synthetic? (9/30/2003 3:31:23 PM)

Ever since the days of LeRhone rotaries of WWI, the aviation world has moved away (and could not do it fast enough!) from Castor to more sensible alternatives.

Castor is a mixture of different liquids of differing densities and viscosities, and they burn and congeal at different temperatures.

One of the classic problems in lubrication theory in any intro mechanical engineering hydro class is the solution to a journal bearing lubrication. If a lubricant is changing viscosities drastically over a temperature, it ain't a good lubricant. Furthermore, if it congeals and turns to solid, it ain't lubricating no more.



Sport_Pilot -> RE: Castor or Synthetic? (9/30/2003 8:25:55 PM)

Furthermore, if it congeals and turns to solid, it ain't lubricating no more.

Only a very small amount of castor turns into varnish. The varnish is slicker than the metal. Synthetic metanol oils evaporate and burn into a gas before it leaves the exhaust. Which is worse? Varnish on the piston and cylinder, or no oil at all?



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