RE: Substitute nitromethane  
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RE: Substitute nitromethane - 11/27/2007 3:56:07 PM   
Jezmo



Posts: 749
Joined: 6/26/2006
From: Spring, TX, USA
Status: offline 		I am still wondering if there is an apology in the works for downunder. He was called a lier and challenged on several points at least one of which has been backed up with data showing him to be correct. When the question is asked how someone can get away with telling such lies it is very offensive to some. I thought the rules of this site prohibited such postings. Mods please tell me what I am seeing wrong here. I must not get it. I certainly do not agree with everything DU posts but I never thought of him as telling lies. We all have opinions and sometimes have our facts wrong but that does not makes us liers. I'll go away now but I sure don't understand this one.

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RE: Substitute nitromethane - 11/27/2007 4:18:10 PM   
HARC_PT


 

Posts: 16
Joined: 8/9/2005
From: vnf, PORTUGAL
Status: offline 		ok!

What do you guys think about this:

Ethanol - 70%
Benzene - 5%
Acetone - 5%
Synthetic Oil for 2-stroke engines - 10%
Ricin Oil - 10%

Would this mix work on my TRX2.5R without damage it?

< Message edited by HARC_PT -- 11/27/2007 4:20:54 PM >

(in reply to downunder)
       Post #: 27

RE: Substitute nitromethane - 11/27/2007 5:02:34 PM   
blw



Posts: 4457
Joined: 3/15/2004
From: Auburn, AL, USA
Status: offline 		Jezmo- I didn't find the comments you are talking about, or I would have removed them. I can see the disagreements but they seem to be okay at the moment. We all get worked up over these sorts of subjects it seems. I hope we can keep it civil and friendly no matter the disagreements.

Red B- I have not seen any proof or claim that any synthetic oil protects like good old castor, newer European oils or not. The bottom line still is that synthetics burn to ash at lower temps than the point where castor provides better protection with 'varnish'. The varnish is protective whereas ash is not. Also, castor probably still provides far better rust prevention than synthetics. Myself, I use a blend of synthetic and castor.

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RE: Substitute nitromethane - 11/27/2007 7:33:39 PM   
blw



Posts: 4457
Joined: 3/15/2004
From: Auburn, AL, USA
Status: offline 		Thank you to the person who PM'ed me about where I was wrong. Yes, a couple of comments crossed the line but it doesn't make much sense it hacking up that message and the responses to it now. I dropped the ball on this one. However, I will edit them if anyone asks me to.

Calling someone a name because you disagree with them should not be tolerated here. For the record, I've read hundreds of posts by Downunder and I've never known him to lie about anything. I don't always agree with some of his views, but he has always seemed to be honest and polite. On the same token, I don't know of anyone who has agreed with a lot of my opinions either.

This should not happen again.

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RE: Substitute nitromethane - 11/27/2007 8:18:43 PM   
XJet


 

Posts: 3215
Joined: 3/31/2003
From: Tokoroa, NEW ZEALAND
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quote:

ORIGINAL: blw
Red B- I have not seen any proof or claim that any synthetic oil protects like good old castor, newer European oils or not.


My observations may challenge that (to a degree).


quote:

The bottom line still is that synthetics burn to ash at lower temps than the point where castor provides better protection with 'varnish'. The varnish is protective whereas ash is not

There is a *very* interesting twist to this however -- which indicates that *some* synthetics may offer *more* protection than castor at high temperatures. It's not *just* the boiling-point that counts when you're examining the hi-temperature "last gasp" performance of an oil.

quote:

I use a blend of synthetic and castor.

So do I, but I'm considering revisiting this choice since I performed some pretty comprehensive testing.

Full review of my findings and video evidence to come (but not on RCU -- because after all, I may need to edit such an large and complex post at some stage and this seems to be a "luxury" withdrawn from my account).




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RE: Substitute nitromethane - 11/27/2007 9:42:39 PM   
Luna_Rendezvous



Posts: 140
Joined: 8/12/2007
From: Brisbane, AUSTRALIA
Status: offline 		Well I do need to make an apology to downunder, and I do so unreservedly and if I offended you, I am indeed sorry! However I will not be rushing out to buy any Castrol M in the foreseeable future.

< Message edited by Luna_Rendezvous -- 11/27/2007 9:43:50 PM >

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RE: Substitute nitromethane - 11/28/2007 1:53:24 AM   
lukesp



Posts: 355
Joined: 4/24/2006
From: BrisbaneQueensland, AUSTRALIA
Status: offline 		OK, I want to see genuine proof that nitro cools an engine. I have always seen the opposite myself. Someone tried to tell me recently that nitro carries away the heat. How when it's already combusted? With castor based fuels varnish forms with heat, the more nitro the faster the varnish forms.

Don't bother quoting Wikipedia either, it's full of flaws.

< Message edited by lukesp -- 11/28/2007 1:54:39 AM >

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RE: Substitute nitromethane - 11/28/2007 2:32:16 AM   
XJet


 

Posts: 3215
Joined: 3/31/2003
From: Tokoroa, NEW ZEALAND
Status: offline
quote:

OK, I want to see genuine proof that nitro cools an engine


I would suggest that perhaps nitro *can* allow you to tune an engine to run cooler (by richening it up a whole lot (beyond the ideal stoichometric ratio) and thereby sacrificing some of that extra power for lower running temperature), BUT, if you tune for max RPMs then your engine *will* run hotter. Here's some supporting evidence:

A quote from the bottom of this page


Nitromethane is basically rocket fuel. It contains its own oxidizer, and so it makes power based on how much nitro you can force into the combustion chamber rather than how much air your engine is capable of pumping. The only drawback to using more nitro is that your engine will either melt or explode, with the explode event occurring more often than the melt event. To tone the nitro down, it is mixed with alcohol. Alcohol has the benefit of having a very high latent heat of vaporization, which means that it cools the engine a bunch

Do you think these guys know what they're talking about perhaps?

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RE: Substitute nitromethane - 11/28/2007 2:48:54 AM   
lukesp



Posts: 355
Joined: 4/24/2006
From: BrisbaneQueensland, AUSTRALIA
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quote:

I would suggest that perhaps nitro *can* allow you to tune an engine to run cooler by richening it up a whole lot (beyond the ideal stoichometric ratio) and thereby sacrificing some of that extra power for lower running temperature


The same thing can be achieved with straight methanol. The idea, amongst most, of using nitro is the extra power to be had. So we add nitro, then run it rich to overcome the effects of nitro?
We are talking about 2 stroke model glow engines, not bonneville racers, drag bikes and certainly not drag cars. There is a remarkable difference in operation. I have personaly seen the end result of a nitro induced meltdown years ago, and the engine DID melt. 60 % nitro was used, unknown oil/oil content. It was a CL speed engine where speed meant everything and the operator obviously went just that bit too far with a lean run.

I constantly hear of nitro being a cooling agent in model fuel, well it may cool the crankcase incoming, but it's what it does in the combustion chamber that has far more importance to me. Energy = heat the last time I looked.

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RE: Substitute nitromethane - 11/28/2007 3:03:13 AM   
blw



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Joined: 3/15/2004
From: Auburn, AL, USA
Status: offline 		Good to see you back, XJet.

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RE: Substitute nitromethane - 11/28/2007 3:05:48 AM   
lukesp



Posts: 355
Joined: 4/24/2006
From: BrisbaneQueensland, AUSTRALIA
Status: offline 		I am not against nitro myself, I use it in several of my engines, not all. I am against such blanket statements as " nitro cools an engine", only if the engine is run rich in accordance with the quantity of nitro present, sure. The temptation for most is to always push for the fastest run, so nitro = extra heat in general.

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RE: Substitute nitromethane - 11/28/2007 3:34:35 AM   
downunder



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Joined: 10/10/2002
From: Adelaide, AUSTRALIA
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quote:

ORIGINAL: Luna_Rendezvous

Well I do need to make an apology to downunder, and I do so unreservedly and if I offended you, I am indeed sorry!

No problems Luna and no hard feelings either .

BTW, I'm not saying that Castrol M is perfect either because it can form carbon deposits on the piston crown and combustion chamber. The photo below is one of my engines after about 30 hours although it cleaned off easily. OTOH my Enya 60X after considerable running hasn't got the slightest trace anywhere including the exhaust. A lot of people use small amounts of synthetic as a blend to keep the internals clean but this also removes the protective varnish which I prefer to have. I've never experienced the "sticky ring" syndrome either even with one engine that had several hundred hours on it.

Attachments
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< Message edited by downunder -- 11/28/2007 3:35:40 AM >

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RE: Substitute nitromethane - 11/28/2007 3:44:01 AM   
downunder



Posts: 3116
Joined: 10/10/2002
From: Adelaide, AUSTRALIA
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quote:

ORIGINAL: HARC_PT

ok!

What do you guys think about this:

Ethanol - 70%
Benzene - 5%
Acetone - 5%
Synthetic Oil for 2-stroke engines - 10%
Ricin Oil - 10%

Other than the benzene it's worth a try because a few have reported good results using ethanol instead of methanol. Power will be down a little compared to methanol but fuel consumption will also be down.

Benzene is carcinogenic which makes me think back to the '60s when I used to pour a gallon of it into 10 gallons of petrol for my TR3A.

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RE: Substitute nitromethane - 11/28/2007 5:35:48 AM   
Luna_Rendezvous



Posts: 140
Joined: 8/12/2007
From: Brisbane, AUSTRALIA
Status: offline 		I never said nitro itself cools the engine, but the richer needle setting does, once you start to go above 20% you need to lower the compression ratio with head shims or will overheat. As fare as varnish is concerned, I've run up to 40% nitro in the Tee Dees and not had a significant/noticeable increase in varnish, varnish is just plain weird, it generally gets worse with humidity, and some days it doesn't? Fore instance this just this last Sunday I taught two youngsters how to fly control line, and we must have put through 20 tanks fuel through a well used blackwidow engine, and when we striped it later in the day it was as clean as a whistle. While a couple of weeks ago I was running in new old stock golden bee and it varnished up after just two tanks, and that was using a lower nitro fuel.

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