50%?!?

[Zach_406]

Hey everyone. I just figured id run this by you guys. last weekend me and a couple guys went to out gravel pit to run our savages, and I got out ran by a bone stock x 4.6! My truck has the picco .28 with the buku pipe and the high speed third gear, and 17\47 gears. the only thing my buddy had done, was that he used his "home brew" 50% nitro. The thing was insanely fast! and to my surprise it actually ran fairly cool, like 220 to 230. Now everyone I have talked to has said that it might be fast, but it wont run very long. What do you all think?

 

[XxxNate's SavagexxX]

i think to beat you he had to be over revving.....his engine his gonna blow up soon.....IDEA: ask him to race a long race and see if his enginell blow! hahah no no JK but still id much rather have my savage be slower and richer and have my engine for longer...so if he wants to have insane power for like maby three or less(just a guesstmation)gallons than so be it... i want to get at least 15 gallons out of my lrp....so i tell him but if he is making nitro fuel he probably knows already..

 

[SunkenMetal]

I am not an expert on this subject so take what I say with a grain of salt and please anyone if I say something that is incorrect, let me know...

Running higher nitro content does produce more power, but it can shorten the life of your motor.

Nitro methane combusts in your motor do to a catalytic reaction with the element inside your glow plug and compression. So if your nitro content is higher than what the motor is designed for it will predetinate causing damage to the motor. Predetonation can be avoided buy lowering compression in the motor by shimming the head, and using the correct glow plug.

Nitro Methane content can effect RPM’s generally more Nitro equals mote Revs.

Also another factor with the temperature is oil percentage and type of oil used in the fuel. Most popular fuels use a combination of Castor Oil, and Synthetic Oils. Castor Oil Actually lubricates better as it heats up. As Castor oil heats up it breaks down and creates a film that bonds better with motor parts and its lubricity increases. I cannot say much about the synthetic oils as it is a proprietary information of the fuel manufacturers.


Size of the motor is also a factor, larger motor handle heat better because there is more mass to absorb heat, also types of metal in the motor can affect heat temperature readings. Different alloys absorb and dissipate heat at different rates…

Hope this helps you out… But like I said these are my opinions on this subject...

 

[XxxNate's SavagexxX]

ya i think he is running the stock 4.6 so that engine does not have much longer...he might be over revving to like 40,000or something and when he puts the least amount of strain on that engine it will pop..

 

[SunkenMetal]

ya i think he is running the stock 4.6 so that engine does not have much longer...he might be over revving to like 40,000or something and when he puts the least amount of strain on that engine it will pop..

Well i can't really say anything about that, his motor and his money.....but i give him props for trying out his own blend of fuel....

 

[Tom H.]

i give him props for trying out his own blend of fuel....

We're gonna start seeing this more and more as Nitro becomes more expensive and harder to buy.

 

[Shaun]

sounds like he has a rocket on his hands thats for sure but i agree with what was said above, it will affect engine life I'm sure!! the question i have is are you 100% sure the motor is stock? what i mean is it might be the stock engine but has it had any modding done to it? "porting,polishing"

 

[SunkenMetal]

We're gonna start seeing this more and more as Nitro becomes more expensive and harder to buy.

There is a guy here in Houston that makes fuel for R/C i Haven't tried it yet cause i have 2 gallons of Odonells, but once i use all that up I'm going to give it a try, ive heard nothing but good things about it, and its half the price of the brand name stuff...

http://www.ritchsbrew.com/rb.html

 

[Shaun]

There is a guy here in Houston that makes fuel for R/C i Haven't tried it yet cause i have 2 gallons of Odonells, but once i use all that up I'm going to give it a try, ive heard nothing but good things about it, and its half the price of the brand name stuff...

http://www.ritchsbrew.com/rb.html

i think it would be cool to make your own aslong as you don't manage to blow yourself up lol

 

[SunkenMetal]

i think it would be cool to make your own aslong as you don't manage to blow yourself up lol

lol boom i guess do it in a well ventilated area and make sure you aren't loaded with static electricty like when you work on a computer.

 

[YeahYeah]

I have talked to a guy who said he used to make his own nitro fuel, but now he just buys it from the store because it was getting more and more difficult for him to get nitromethane to make it with.

As for the 50% fuel ... I've never heard of anyone using something high really than 33%, so even though it seems to make his ride scream, it really is probably destroying his engine - otherwise why wouldn't pros use the stuff? (or is there a nitro limit at sanctioned races?)

 

[nickmind]

Couple things come to mind. First we are talking about a k4.6 vs. picco .28 . The last time I seen a picco .28 was in a revo, and I was killing that truck with my savage that had my cheapo SH .28 . The reviews of picco big blocks are not the greatest. Not saying the are bad. But B grade to say the least. With some right tuneing (using normal 25% to 30% fuel). I can easly see the k4.6 beating out picco .28 . We are not talking about two different classes of engines, is pretty much what I am saying.

And two, I can not see the engine staying that cool. 230? How did you measure that? If it is true he was using 50% nitro, i can not see the temps staying that low at all. Think about it, if he's using fuel that is that high in nitro content, you could not get enough fuel (meaning the oils needed to lube the engine, and keep the engine cool) without bogging the engines power. So no matter if your have a rich tune settings. Even at the higher rich setting, the engines will see less oils, meaning the engine will get hotter period. Not saying it will create a fire ball. But should be over 250 if not 280. Something is not adding up.

Because this is the case, less oil = more wear.

My mind at work!

 

[Bankrupter]

Couple things come to mind. First we are talking about a k4.6 vs. picco .28 . The last time I seen a picco .28 was in a revo, and I was killing that truck with my savage that had my cheapo SH .28 . The reviews of picco big blocks are not the greatest. Not saying the are bad. But B grade to say the least. With some right tuning (using normal 25% to 30% fuel). I can easily see the k4.6 beating out picco .28 . We are not talking about two different classes of engines, is pretty much what I am saying.

And two, I can not see the engine staying that cool. 230? How did you measure that? If it is true he was using 50% nitro, i can not see the temps staying that low at all. Think about it, if he's using fuel that is that high in nitro content, you could not get enough fuel (meaning the oils needed to lube the engine, and keep the engine cool) without bogging the engines power. So no matter if your have a rich tune settings. Even at the higher rich setting, the engines will see less oils, meaning the engine will get hotter period. Not saying it will create a fire ball. But should be over 250 if not 280. Something is not adding up.

Because this is the case, less oil = more wear.

My mind at work!

+1 with the oil content. what % meth is he running? As he may have bumped the oil as well but Nitro acts as a "super charger" its O2 content is twice what a carb can bring to the table. So it will add a ton of power if it can keep from melting plugs. Get us the full blend %'s Nitro is one of 3 parts. I do disagree with a K killing a a P3. I have had both and the K does not have a chance. The SH is a sister mill to the LRP and she is a slayer. Why do you call it a cheepo ?

 

[nickmind]

+1 with the oil content. what % meth is he running? As he may have bumped the oil as well but Nitro acts as a "super charger" its O2 content is twice what a carb can bring to the table. So it will add a ton of power if it can keep from melting plugs. Get us the full blend %'s Nitro is one of 3 parts. I do disagree with a K killing a a P3. I have had both and the K does not have a chance. The SH is a sister mill to the LRP and she is a slayer. Why do you call it a cheepo ?

Picco is better, but not by worlds. Plus, I meant with the high nitro contect fuel.

I don't know why, I do like my SH's (have two). I have gotten beat with them before, (could have been my driving I guess.) But what do you mean the SH is a sister to the LRP. LRP kick straight tail! Are the manufactured from the same plant?


Just a side note, I'm about to pull the trigger on the newer OS v-spec .21 for my buggy and truggy

 

[Double-O-Zilch]

One thing I learned at the LHS yesterday is that more nitro equals a cooler eng. Running 50% may be cooler but at what cost to the eng?

 

[Larsenracing]

The LRP and the Sh are very simular mills and are from the same facility.

I also disagree the Picco P3 is a machine. It is built of better materials with tighter tollarences and is actually faster than the LRP by a touch. However it is not near as easy to tune. Like everything thought some of them are duds.

 

[Bankrupter]

Thanks for answering that Larson. +1 lol
And yes Parkermarsh it does add cooling too. But the energy it will give off at 50% I would think<--- offsets its cooling effect. BUT THAT IS GUESSING !!!

 

[nickmind]

Thanks for answering that Larson. +1 lol
And yes Parkermarsh it does add cooling too. But the energy it will give off at 50% I would think<--- offsets its cooling effect. BUT THAT IS GUESSING !!!

Back you and Larson brothers? J/K Well I have my opinion of the picco .28 mills, and you have yours, so please enjoy. You have missed my point. I was not saying they are bad. But does not matter. I would buy my $160 engine over the $210 engine any day of the week including Sundays. 🙂

On the topic of heating. This is true Nitromethane is a cooler element (meaning when you touch our rc nitro fuels, and it feels cool to the touch. That's what you're touching, the nitromethane in the fuel.) Which in turns cools the engine down. But again we have missed the point in my previous post. So let me try to explane it a different way. If i can.

Why does the engine heat up? answer: (glow plug igniting nitro, which causes FIRE! correct) and another answer is when the piston is moving up and down the sleeve (high rpm) causes friction. Friction is one of the heat sources of the engine. If we do not cool this friction down, it does not matter if nitromedthane is cool, going through a hot piston, sleeve and crackcase (remember we're not cooling down friction), by the time the nitro hits the glow plug, its warm, and then ignites, and more heat is created.

So what do we do, we add different types of oils to prevent friction, in turn less heat. This is why i have to say that the temps would have to go up. By playing with higher nitro % we are in turn robbing the engine of the oils, the lubricants the prevent friction.

So bottom line, less lubes = more friction, more friction = higher temps. More friction and higher temp = killing the engine's life.

But I still say if you are running higher nitro % your temp will be higher then 230. Thats it, i am going to bed. 4:10 in the morning for me.

 

[Zach_406]

we actually checked the temp with three differant temp gauges. and i think if I remember right he was saying that he had 50% nitro, 18% oil and the rest methanol. I know how crazy this stuff sounds, which is why I figured i'd run it by you all, but ill see the truck run again this weekend, and ill let you know if its still together or not. thanks for all the info and ideas.

 

[SunkenMetal]

Your welcome Zach.........keep us informed....

 

[Bankrupter]

we actually checked the temp with three different temp gages. and i think if I remember right he was saying that he had 50% nitro, 18% oil and the rest methanol. I know how crazy this stuff sounds, which is why I figured I'd run it by you all, but ill see the truck run again this weekend, and ill let you know if its still together or not. thanks for all the info and ideas.

Yep plenty of oil! Castor oils don't burn. So I don't know where nick is trying to go saying it getting robbed by adding more nitro. But one way or the other and back to the main question. I don't think this mill will last long with that mix. Just from the extra strain. Not heat or any other reason. I think the con rod will go long before it loses pinch. Or detonation will kill it. Time for bets!!! 10 bucks on 2 gals... Zack start a poll on gals for fun 1,2,3,4 gals. Keep us posted and this is neat stuff. Thanks for sharing and asking!

 

[nickmind]

Yep plenty of oil! Castor oils don't burn. So I don't know where nick is trying to go saying it getting robbed by adding more nitro. But one way or the other and back to the main question. I don't think this mill will last long with that mix. Just from the extra strain. Not heat or any other reason. I think the con rod will go long before it loses pinch. Or detonation will kill it. Time for bets!!! 10 bucks on 2 gals... Zack start a poll on gals for fun 1,2,3,4 gals. Keep us posted and this is neat stuff. Thanks for sharing and asking!

You still don't get it, that is whats in the gallon, thats.... Oh man, Nevermind!!!

 

[Bankrupter]

You still don't get it, that is whats in the gallon, thats.... Oh man, Nevermind!!!

What don't I get? Its a custom mix. Not Nitro added to pre made stuff. You add the 3 parts yourself. Your saying that the oil will suffer form adding nitro. I don't know why or where your going with that. That % oil is more than enough for any mix. Ten % is plenty. From the last post this has more oil than most on the market and less meth. So Oil has be compensated for. What are you trying to say. don't get frustrated over a forum. I want to know what your saying please continue...

 

[Purenitro]

Running high nitro is not as bad as you may think, when I ran my boats I bought over the counter 65% nitro, 20% oil with 15% alcohol. Yes with that high of nitro the plugs wore out quickly 15-20 minutes, due to the lack of alcohol and heat of nitro. Now the other thing to consider is higher nitro needs a more rich setting thus more cooling.

With regular 20%-33% nitro and 8%-16% oil you have roughly 60%-65% alcohol. Alcohol has the most cooling effect on an engine, up to 70% of the cooling is from the alcohol in the fuel. The cooling head takes care of the rest. As for the internal friction, when an engine is new it has a mechanical pinch at the top of the sleeve and this pinch causes heat from friction. This is why we have to run an engine kind of (not slobbering) rich, to overcome this heat buildup. Once an engine is fully broken in, there is a film of lube that prevents the piston from making mechanical contact with the sleeve so there is very little heat generated at this point, unless running very lean.

If you have ever switched from 20% to 30% nitro, you should have had to richen up your needles a bit. You have to tune the engine to the nitro content you are running, the more nitro the richer the setting. Power generates heat so yes you have way more power but you have way more cooling agent flowing through the engine. The thing is, you can run higher nitro with a richer setting and not burn up plugs, where as if you want a race tune it will for sure burn them up fast.

The lifetime of the engine is not realy affected from running higher nitro if you keep a few things in mind, don't over rev it! it can grenade even with stock timing profiles, don't run it with a race tune as that will lead you to let it wind out (over reving) The connecting rod usualy goes from extended high rpm, not from extra power. Keep an eye on your temps, temp it "right after a pull" as the needles may become more sensitive.

"Bearings" This will lead to premature engine failure!!! Although the common theory is that the front bearing is what seals the engine in the front, this is incorrect. Just behind the front bearing the case is milled to very tight tolerances with the crank and this is what seals the front. Now with the extra power comes extra wear and tear on the bearings, once the front or rear bearing starts to go the crank starts to wobble and will wear out this tight fit, the engine will start to leak at the front and tuning will go out the window. If you have ever looked behind the front bearing, you will see a little hole, most people think that this hole is for lubrication of the front bearing. They are partly correct, the thing is, the lube enters the bearing from between the crank and block. It is then sucked back into the engine via the hole as it always has a negative pressure from the intake of the engine, the little hole comes out just below the carb. If that hole gets blocked it will cause the front bearing to leak as well. Change the bearings every gallon, two is pushing it.

Any questions fell free to ask.

 

[BIGDAN89]

so you saying i should change my front bearing every gallon heh i dunno about that but i do know the higher nitro content is made for boats not rc trucks so safe to say hes blowing his motor up as its not made to run 50%

 

[Purenitro]

so you saying i should change my front bearing every gallon heh i dunno about that but i do know the higher nitro content is made for boats not rc trucks so safe to say hes blowing his motor up as its not made to run 50%

No, not with regular fuel, maybe 3-4 gallons if you want to be safe, some bearings last many gallons, some go in the first gallon. The difference between boat and truck engines is very minimal, liquid cooled head and maybe higher timing is the only difference.