1Eye

My Feedback: (2)

In their instructions, HPI gives this stern warning about not using "model airplane fuel" since it may not have the proper lubrication qualities ... What kind of weasel-worded BS is that? [:-] Here are a couple of more directly worded questions:
1. What percentage of lubricating oil (castor, synthetic, etc.) - by volume - is a good number to have with, say, 15 to 20% nitro content?
2. What variety (brand/nitro content) are you guys using in your HPI trucks?

Mike

Savage545

I've been using Odonells 20% nitro, and it's been working great for me.

Dale Gribble

My Feedback: (4)

Good question. Airplane model fuels typically run an incorrect caster/synthetic blend content for nitro cars because they don't rev as high or run as hot and typically have lower nitro content. Not saying there aren't 'crossover' fuels that can be used in both (e.g. Powermaster), but it's better to stick with specially Nitro car formulated blends.

I can tell you that most .21s and above do not like 18% oil mixture fuels like Traxxas and Blue Thunder Sport. Those fuels seem to be better suited for hotter running 'small blocks' like the Traxxas 2.5.

I swear by Trinity Monster HP 20%. It is basically all I use. 13% oil content and a good mix of quality lubes for most engines. Two words- Consistent and predictable. They way I like my fuel.

Haulin bass

Shoot for 10-13% oil for extra protection(and cooler weather), Watch out with byrons fuel as they mesure by weight not volume, personnally I wont touch anything with over 13% oil as they tend to run warm and genrally just goop things up.
make sure when chosing your fuel to be aware of the castor content, its what protects at high heat but if you have to much of it your owb could start to slip.Also fuels with allot of castor gum up faster.
I recomend you stay away from house blends and traxxas/powermaster fuel and go with Sidewinder,trinity,odonells(not rtr),maxys,werks, or a few others I cannot remember. There are only about 4 places in the US that make the fuel so check the label on the bottle to see who made it.

1Eye

My Feedback: (2)

I don't disagree with what you said but it almost sounds counterintuitive. By that, I mean ducted fan engines (from .45 to .91 in size) run anywhere between 18K and 23K+ RPM and they seem to "like" around 20% oil content with some of it being synthetic. At least that's been my experience 'cause I've run/flown many gallons of ducted fan fuel!
So, it would seem that fuel with 20% nitro and 13% oil is the all-around choice?

Mike

thunderw0lf

Going by weight is the best way to blend something because the weight isn't affected by tempurature expansion and contraction which makes it much more consistant, that's why all the food makers go by weight and not vloume.

Haulin bass

yes thats true but when every one else does it a diffrent way it makes for confusion.

Kanza

The lubricants and chemicals in the fuel play a major role in cooling the engine. Most of your airplane fuels use different chemicals that are designed for that application. An airplane is always moving, so there is a constant stream of airflow going over the head. A car or truck engine on the other hand, is designed to stay cool when sitting still. Using airplane fuel would cause the engine to overheat, thereby breaking down whatever protection the oil in the fuel would provide. The result would be one toasty paperweight.

My Savage runs on Trinity's 20% Platinum, if that helps.

alvinl

I currently use Traxxas 20% fuel in all my trucks. I have been thinking about switching to Byrons 20% because everyone says it is a better fuel and it's basically the same price. Does anyone think there will be a problem switching? I know I will probably have to retune, but I have to do that almost everytime I run anyway. Also, will the Byrons be good in the Revo with a stock TRX 2.5r?

Sorry for the hijack!

1Eye

My Feedback: (2)

I think your logic may be a bit flawed as stated but I understand the point you're trying to make. Thanks for sharing your fuel "flavor" I think I'll try to find some.

Mike

Kanza

Only as flawed as the chemists and engineers who make my life difficult.

Good Luck.

tmodlin

I use whatever my LHS sells the most of in 20%. Last fall was blue thunder this spring will probably be trinity since they stopped stocking blue thunder. I have yet to see a difference in performance based on brands when they have the same nitro/oil content.

cchrider

I run Trinity Monster fuel. I really like it. Little bit pricy but o well. My friend run the HPI fuel, and I like it also. I have ran BK Racing fuel also, and its alright.
cchrider

1Eye

My Feedback: (2)

Some of the preferred fuel flavors being reported have oil content all the way up to 20% - especially the so-called "break-in" fuel - with most falling in the 15-17% range. So I have to wonder since many of the so-called car/truck fuels sell at a premium compared to airplane glow fuels having essentially the same content [>:] But hey, the labels on those bottles of car fuel look cool if nothing else.

So far I've run a couple gallons of garden variety 15% (nitro) with ~18% synthetic oil model airplane fuel through my Savage 25. That stuff costs ~$16/gal at my lhs compared to the roughly $40+/gal cost of "car fuel." My sons/grandsons beat the living crap out of that Savage and the HPI motor seems happy. The engine is needled for power (i.e., doesn't gag on the low end and gets good "smoke" on the high end) and I've never had any high cyl. temp issues. Am I missing something other than bragging rights on paying a lot of moola for fuel or ... ? [&o]

I just got a new 24.7 Pro (*very* sweet) for mine and I'll install it after the HPI 25 wears out/pukes or Spring comes - whichever happens first!

Mike
... not a chemist but your worst nightmare of a space systems engineer

itspuddingtime00

I run blue thunder in both my RB TM323 revo and my 4.6 savvy. I have been thinking about switching to O'donnel, but its like 5 bucks more at my LHS, and the ones they do carry usually sit on the shelf for a while.

Dale Gribble

My Feedback: (4)

You are probably right MrMike. it's one thing to say this or the other, but if you put in plane fuel, and it works, who can argue that?

I have always been a tool of effective marketing anyways. I ooh and aah at pretty labels. I just go off of what the market and rags tell me- I don't experiment like you did rather successfully. Of course, the most I have ever paid for a gallon of Trinity is $25-30 tops. $40 and I might start rethinking plane fuel too.

The only food for thought I will throw out to think about is this- You are at high altitude, and I am not sure how sea level or lower altitudes would respond? not my specialty. Would a Nitro Rc car guy be fine running your same fuel at 0'?

big savage man

I have been using trinity monster power in my savage 20% nitro it has good throdle response with this fuel so give it a shot

1Eye

My Feedback: (2)

Dale, at our altitude (just shy of 7K MSL) there's less O2 and we just needle accordingly; oh well. This just translates to less power (18-20% less depending on which chart you believe) and running less/more nitro or oil doesn't alter anything substantially at our higher altitude.

Mike

AJ DRAGON

Hi

Hay I have been using Tower Hobbies Tower Power 15% premium fuel in all of my nitro car's and trucks for over 5 years now and I have had absolutely no problems with it.

Frost_

My Feedback: (1)

Nitromethane is oxygen bearing, and you will notice the difference going from 20% to 30% fuel... I fly with a guy who moved here from Denver... he flys with a 10% blend now and it makes as much power now, at 200' above sea lvl as he made on a locally blended 30% fuel.
One of the reasons plane fuels are not reccommended (I fly too..) is that to get the engine to rev and "clear-out" requires a leaner setting. This usually makes truck engines run hotter. Remember, at a constant % of nitro, when you go up on oil content, you also go down on the methanol component. Also, if you use a roto-start (and this can happen to pullstarts too) the excessive oil will work it's way out of the engine backplate where the shaft protrudes and can make the one-way bearing slip. Many people have bought new $18 one-way bearings because they thought the ones they had were bad. In fact they were just slipping from the excessive amount of oil.

green river rc

My Feedback: (2)

I have ran 7 gallons of Wildcat 20-20 YS blend (total synthetic "airplane") and 1 gallon of Blue Thunder through my Savage, since I'm basicly an airplane guy. My instruction only said 20% nitro and nothing about not using airplane fuel. All I can say is that it takes longer for the engine to warm up with 20-20, all the extra oil just goes out the pipe. I'm not saying it's better but Wildcat 20-20 blend is $15 out the door at my hobby shop, and by the way...it still wheelies just the same. Synthetic oil doesn't gum up anything either, it's the castor oil doing that just ask any of the older control line airplane guys that one.

Just my observations.

1Eye

My Feedback: (2)

I don't use castor oil anymore either. I run a blend of RedMax 30% nitro fuel with 18% synthetic oil in all my (airplane) Sato 4-cyc. engines and I may just give that a rip in the Savage's stock 25 and see what happens. I know I'll have to re-needle it and keep an eye on head temps. while doing that.

Also, this baloney of "the engine will not run right if you switch back to a lower content of nitro" fuel has me puzzled. Maybe deposits on the glow plug element ... who knows? The engine doesn't have a clue of what sort of fuel is being delivered to it - it's just parts & parts is parts ...

Thanks for all the feedback and tips so far. I'm gonna continue to run airplane fuel for a while at least.

Mike

zavzilla

hi you say you cant use airoplane fuel well let me tell you some thing after 10 years with planes and 5 with cars most fuels are the same ie senthetic or caster bashed fuel ,difrent fuel makers use difrent oil in therefuel to lubricate if you ran 10percent fuel you will have less power but tone of lubrication . most brands ie dynoglow, model technecs, tornado, make fuels for difrent parts of the hobby ie flying or cars . hope that helps

1Eye

My Feedback: (2)

Me? I never said anything about not being able to use airplane fuel, vis a vis car fuel - that's been the point of this entire thread: As I know and as you and others have pointed out, the basic stuff in the fuel is the same whether it's branded car fuel or airplane fuel or has a cool/kid-appealing label on the jug ... [>:] It just happens that, unlike model airplane fuel [which might be the same], the car-branded fuels seem to be marked up to a rip-'um/gyp-'um price level. (hello?)
Obviously, many have broken the code and know they can run cheaper (probably indentical model airplane) fuel without any harm to their engines or significant tradeoff in performance.

Mike

zavzilla

hi mrmike i did not say it wos you . i just pointed it out that most fuels are the same .