bjonaiti

See reverend...right there is where I get upset at the disrespect you display. Pu*** A** come get slapped when you start talking s*** on this forum. I'm going to tell the mod's and you'll be really sorry. You'll be begging for forgiveness!
I think I want to come meet you somewhere. Let's meet halfway!

theRCreverend

What is wrong with you??? I never said anything about how it will affect temperatures. I simply said it ran cool. If you want to stroke your ego and discuss the effects of varying nitro content on engine temperature feel free to do it somewhere else. I never once mentioned it here. Don't throw words into my mouth so you can win an argument you're having with yourself.

I've been running between 0 and 5%for years, and this motor is on it's 2nd gallon of fuel with no problems. It runs cool with no nitro, period. I don't care what the "theory" tells you, Ihave actual real world data to go by. How cool it runs or if it runs cooler/hotter than with higher nitro content is not the point.

Foxy

Keep it civil or don't post. All of you. Any more of that kind of stuff, and this will be locked, and further action taken against the instigators, you have been warned...

Right, back to topic...

1) The engine will not necessarily run any hotter with 0% nitro, as it is not the nitromethane that cools the engine (at least, not at a race mixture, negligibly so). Nitromethane is a catalyst, it speeds the reaction, making extra power. The fact that it also evaporates quickly ASSISTS a LITTLE in cooling the engine (that's why it FEELS cold even though it's not really cold, it's your skin tricking you, as it evaporates and takes the heat from your skin away with it). If you're running a race tune, there isn't very much unburnt nitromethane, and what there is, is cancelled out when the glow plug ignites the mixture the next stroke

2) Your RTR mills have more power than $500 race engines? Really? That's a bold statement. I've never seen even a modded RTR engine that can touch my box stock Ninja .28, or even come close.

3) 28 or 21 are equally acceptable in truggies. I have a Ninja .28 in my Mugen MBX5T Prospec. I'm not a noob, and the prospec is not a car for noobs, nor is the engine, which is specifically designed for that truggy. I also race occasionally, it is a legal size for racing at most clubs, since people realised that no real advantage is gained by the extra displacement.

Lastly, and as said above... The nitro content has maybe a 5% effect on the cooling of the engine. Your oil is doing the cooling (or rather preventing the friction that creates heat, remember these are not ringed pistons). The more nitro content, the more violent the explosion in the cylinder, hence the need for reducing compression when going to high nitro content. Stronger reaction, more heat. It balances out. IF you run REALLY rich (which you must be to get the temperatures you are talking about, WOW they're LOW! I run my engines around 260), then the cooling effect is definitely more. But I can tell you on a race tune, that 30% makes my engine hotter than running 20%, and gives only a slight performance increase. I generally run 20% for this exact reason.

teacher brent

Awe come on mod, these guys are funny when they rant.

Foxy

Back to topic please, seriously.

theRCreverend

The biggest concern at this point is the use of baby oil. I was not too sure of it myself, but so far it has ran just fine on 4 bottles of homemade fuel. That is around 1 quart of fuel. It smokes a little more than normal, but engine temperatures are reasonable. I don't use a temperature gun, but instead I put a drop of water on my cooling head to check temperature. I have been doing this for decades and had no problems with motors. I tune them on performance, small smoke trail when at WOT, etc, not to temperature. Tuning to temperature is fine but not necessary. I have owned enough motors to know that operating temperature varies an incredible amount from engine to engine.

THe baby oil is working fine for now. If it wasn't lubricating enough I would have seen elevated engine temperatures.</p>

theRCreverend

Yes and NO. Not all brands are isopropyl alcohol. Do some research and you will learn that somebrands containmethyl alcohol. The methyl alcohol is the one you should use. Isopropyl alcohol willnot work.

Foxy

It's not the cooling you are losing from using a mineral oil, it's the metal protection. While you may not be seeing elevated temperatures, I'd bet my bottom dollar you are wearing your piston and sleeve heavily, slowly reducing compression and power. I bet your bearings are pretty unhappy too. Just get a castor and be done with it. I have to say I don't know much about mixing fuel, I buy my fuels, and would bow to anybody else with a better suggestion for the appropriate oil to try in your application.

Chris_RC

Yes, my modded Mach 427 with RB 45% fuel has more power than OS Speed's. Heck, my v-spec has more power than a Speed. That's why people run speed in buggy, and vspec in truggy. The speed just wears less and is smoother. Plus get runtime towards 12 minutes on my 427.

Exact opposite for me. I would run 30 then 45 then go to 20%. Temps would be 215 with 30%, 185 with 45%, then approx. 265 with 20%. Yes they are all different brands- Byron 30, Nitrotane race 20, RB 45, but it is a general conscience.

colmo-RCU

What is drygas??????

theRCreverend

Maybe I am wearing them, maybe not. There is no factual data that I know of to support either side of that argument as I don't know the lubrication properties of castoroil vs. baby oil. I have since bought more 0% fuel from the LHS. In doing the math it comes out to about the same price per gallon. Not having to mix it is fine with me, but in a pinch the use of gas dry and baby oil worked for me.

theRCreverend

Good for you. Now since you're so smart on the subject, explain to me why a drop of water won't boil off my cooling head when I'm running 0% nitro in my car? It runs like a champon 0%incredible bottom end power, and it has very good top end too.

lez1troubles

You can get caster oil no problem, its the caster beans that could be life threatening.

BuzzBomber

My Feedback: (4)

Folks have been mixing their own fuels for a long time, so there are obviously no inherent problems - good on you for doing something most are afraid to try these days.

If 0% nitro is so bad, then why is that the FAI spec for aerobatic competition? Car and plane glow engines are more alike than different. In my experience, car folks seem much more concerned with squeezing every last ounce of performance out of an engine, longevity a distant second, where in planes and helis reliability and consistent performance is more important than brute power. By and large, you won't find as many people flying high nitro content in a "sport" plane(usually combat and pylon guys use the high-zoot fuel), and several folks I know have engines with 20 or more gallons through them running on blends from zero to 10% nitro. These engines manage to make plenty of power on low/no nitro fuel without overheating, so that would seem to dispel the notion that too low nitro will singlehandledly cause overheating - state of tune and compression seem to be far more important. Just drawing some parallels here. I have also used 5% nitro fuel in my Monster GT when that was all I had on hand, no issues with overheating, minimal retuning required, and not very much of a power decrease from the normal 20% I used.

Back to the oil, you should be able to get castor easily from your drugstore. Any pharmacy grade castor will be fine for your engine. The important thing I've read about castor over the years is that it doesn't start to fully break down until about 650°F, so it will always be capable of lubricating the engine in normal running conditions, and the varnish that forms when castor falshes off at high temperatures helps with piston/cylinder wall sealing, as it has a high affinity for the metals.

ARUP

Hi- Ethanol (EtOH) is the endproduct of a moonshiner's labors if done correctly! Methanol is the stuff in moonshine that the moonshiner didn't want and is what makes you go blind! Since alcohols are sugars and the brain uses sugars as metabolites, alcohols readily cross the blood- brain barrier to be used by ... the brain! The visual pathway uses sugars faster than any other part of the brain. Ethanol causes you to get drunk when it is metabolized and some of the by products of this metabolism create the hangover effects. The by-products of methanol, amond other things, are formaldhydes and ketones. In other words your brain tissues, particularly the optic tract, get 'pickled', i.e. ya go freakin' blind! When a person gets methanol poisoning your ER doc will hook you up with EtOH to try and 'bounce' the MetOH off the receptor sites. Better a really bad hangover than blindness! Methanol is better fuel for RC engines because it is cheaper to produce. Good luck with your fuel.

BuzzBomber

My Feedback: (4)

Leave it to the guy from Kentucky to weigh in on moonshine. I'm just kiddin' ya, ARUP. That's an interesting perspective on fuel costs/hazards and component chemicals, actually.

theRCreverend

There is more to it than just the cost of producing methanol over ethanol. They are similar in the sense that they are both very simple alcohols, but their physical and chemical properties are very different

kaiser01

mmmm....moonshine.

methanol evaporates at a lower temp, so it comes out first. it's known as the "heads" and it's tossed away or labled as poison and used as paint thinner/parts cleaner.
next comes ethanol which is what we drink. after that is the "tails" or the stuff that gives you a hangover.

cheap booze has alot of tails in it, thats why it hurts your head so much. lol


none of this pertains to the topic at hand, but it's more fun to talk about.</p>

HPI_Savage_RC

I have to disagree. The cooling effect of Nitromethane has nothing to do with the rate of evaporation, and the fact that there is little unburnt fuel in the exhaust means nothing. The cooling effect is a result of Nitromethane's high heat of vaporization, or in other words, the heat energy required to convert a certain mass of liquid to the gaseous phase. The heat of vaporization of Nitromethane is much higher than that of methanol, roughly twice as high. This means that the Nitromethane has a significant cooling effect on the engine, as the incoming fuel charge will absorb substantial amounts of heat energy from the metal components. Assuming compression ratios are properly adjusted, these engines do run cooler on higher nitro % fuel.

Nitromethane is also NOT a catalyst in this reaction, as it is burned and produces heat energy and additional moles of gas. The speed of reaction has nothing to do with why Nitromethane increases the power of an engine. I suggest you look up the definition of catalyst before using terms incorrectly.

Nitromethane increases the power of an engine by increasing cylinder pressure, which is a direct result of the slight increase in reaction temperature (Note the difference between temperature and heat), and the substantial increase in gas production. Methanol produces 6 moles of gas at ~1900 degrees C per 5 moles of reactants in a stoichiometric reaction with oxygen, while Nitromethane produces 12 moles of gas at ~2400 degrees C per 7 moles of reactants. This equates to a cylinder pressure ~1.75 higher with Nitromethane.

Don't jump into technical discussions if your knowledge of such matters consists of internet hearsay and illogical speculation.

earlwb

I would suggest using a good grade of 70 weight motor oil if you don't use olive oil or castor oil.

Gas dry is a good idea. But Baby Oil? Tough call there. I would useclear Olive Oil first (maybe even virgin first pressed), Olice oil hasall the same characteristics of Castor Oil plus it has a higheroperating temperature before varnish starts to occur. The model dieselengine people have already used Olive oil with success in their dieselfuels.

Now baby oil is not just a pure oil, the manufacturers add in extraingredients to enhance it, some of these ingredients may cause problemswhen burned and heated up in a model engine.
For example: JOHNSON'S^® Baby Oil Lavender is enriched with lavender andchamomile, ingredients shown to have calming and relaxing properties.Use this gentle oil for a soothing baby massage as part of your baby'snighttime routine.

So we don't know what happens inside the engine with the other ingredients a company may add to it.

Now the classic homemade baby oil was to use a refined light mineraloil and add a drop or two of lavender oil (essential oil) to enhance it.

A more complicated baby oil formula is this one: Purified Water, Mineral Oil, Cetyl Alcohol, Triethanolamine, Aloe Vera Extract, Fragrance, Calendula Extract, Vitamin E Acetate, Methyl Paraben, Chamomile Oil, Propyl Paraben, Butyl Paraben

The problem is no one has any specific information about "mineral oil" itself for useage as baby oil or anything.
So the mineral oil could be anything in the baby oil. We don't know. other than it is a petroleum distillate.

Chris_RC

Nitro burns cool. Oil burns hot. I would like for you to record a video of your car running.

What is the oil mixture? Since you are running low temps, I am guessing approx. 5-9% oil?

Now, run an engien for 10 gallons and see what happens. I can say, " I ran my engine for a quart at 350 degrees and nothing was wrong with it!" But can I say, I ran my engine at 350 degrees for 10 gallons? No

richardcranium

This is starting to get real confusing. I think I will stick to backyard basher from my local hobby store. Cheap enough at $25.00 a gallon. Especially since most of my time is spent fixing my RC rather than running it. Got a heavy finger! (Thats what she said) </p>

savagecommander

this whole thing is out of control- why does it always turn into a "battle of the brains" and usually somebody is name calling. dont ever get into racing... all i know is after a pull down the 1/4 mile my intake manifold is drippy wet like a cold beer- and i run WFO with my gasser on nitro and i never worry about temps...

Foxy

Rather than use the layman's term 'catalyst', which I quite agree is not the scientifically correct term, I (and you) should have used the term 'reaction medium'. Do you think a 12 year old kid reading this is going to understand what that means?

Anything that explodes more violently under compression than alcohol is going to increase cylinder pressure, that's completely irrelevant. I don't pretend I understand what all that crap about moles is all about. Moles are brown furry animals that don't see very well, nobody wants your 6th form chemistry class, all they want is to know why nitromethane develops more power, which you have patently failed to explain in a way 99.95% of the world can understand, so let me have another stab for you... Nitromethane makes more power due to the fact that it does not 'need' large quantities of oxygen to burn, and therefore adds another reactive (sic: explosive) element to the methanol and air fuel mixture without requiring the introduction of additional oxygen. Since the only way to get an engine to develop more power is to burn more fuel, and to burn more fuel, you need more air. We are limited by the air intake on RC cars and real cars, as to how much air we can mix (and therefore how much fuel we can actually burn), nitromethane goes some way toward providing a means of gaining more power without adding more air.

By the way, the vaporisation process you refer to, is also known as evaporation (laymans terms again). It feels cold because it evaporates fast, that's the simple way to explain it and is perfectly acceptable.

I also said nothing about unburnt fuel in the exhaust, what? I was simply debunking the fact that the nitromethane itself is an any MEANINGFUL way responsible for cooling the crankcase, or at least to say that any such cooling effect is quickly cancelled out by the explosion that comes immediately after contact with a glow plug element. In fact there is an optimum for cooling effect/power gain, I don't know exactly where it is, but it's between 20 and 45%.

Internet hearsay? Illogical speculation? Grow up, please. What a surprise that someone who needs regular disciplinary action is trying to call out a mod.

Guys, it's only confusing because someone wants to confuse the situation in order to feel that he got 'one-up' on me, even though it's perfectly clear and understandable what I'm trying to say in the original post, even if the terminology isn't 100% spot on. If it had been, nobody would have understood anyway. God I hope they never let you write an instruction manual...

By the way, hpi_savage_rc... This is not a technical discussion. Perhaps you should look up the meaning of the word 'technical'. lol You want to have a technical discussion? Let me tell you about internet security protocols...

Bottom line guys, if you run a lean tune, more nitro isn't going to cool you down. If you run a rich tune it will, but then if you run a rich tune, what's the point of increasing the nitro content of your fuel since you'll have to reduce engine compression accordingly?

theRCreverend

<span lang="EN">


I&rsquo;ll ask again, why isn&rsquo;t my motor hot enough to boil water when I run 0% nitro? You&rsquo;re the one who said it would overheat and run like crap with no nitro, remember?:</p>

</p>


My engine is running incredibly well, imagine that. There are even others in this thread who said the same of their motors on little to no nitro.</p>

Record a video for you? I&lsquo;m just a &ldquo;newb&ldquo; who puts oversized engines in truggies, remember?:</p>


</p>

Why should I provide video? Do you think I really care what a person like you thinks? You&rsquo;re a know it all, and the more you post, the more it becomes apparent that you have a lot to learn.</p>

As for the oil mixture, I already answered that question in this thread, so find the answer yourself (Hint: your guess of 5-9% is WAY off). Again, you obviously haven't read the thread, but you&lsquo;re so quick to jump to conclusions.</p>

Arrogance isn't working for you, so try something else.</p>

Quote:

ORIGINAL: Chris_RC
Now, run an engien for 10 gallons and see what happens. I can say, " I ran my engine for a quart at 350 degrees and nothing was wrong with it!" But can I say, I ran my engine at 350 degrees for 10 gallons? No

</p>

Who said my engine was running at 350&deg;? Seriously, can you read?</p>
</span>