fhm101

I think coiling pressure line on cars is simply a way to keep it out of harms way. Pressure line length however is important, at least in car applications.
I'm sure there have been reasons for this already posted, but I'm new here so I'll tell you what I've heard, read, and experienced first hand on the subject. The late great Ron Paris said pressure line length was a useful tool for fine tuning transitional response in onroad cars. He also said it was a tiny gain and best left to expert tuners. My own personal experience with this has been that a short pressure line will cause a big (.21 and up) car engine to run lean below half a tank of fuel and also has an effect on how these engines idle. A longer line will help a car engine fall to idle faster which is critical to clutch engagement, or rather disengagement when you come off throttle. Also, the smaller engines used in 10th gas cars and trucks are more prone to flameout with a short pressure line. Why? I don't know, it's just things I've learned from experience.

Hobbsy

My Feedback: (102)

There used to be a so called RCV expert frequent these pages who claimed that using more than 15% lube would put the engines on the verge of hydro-lock. I didn't buy it. I ran my RCV .58CD and .90SP on Wildcat Premium 10%nitro with 16% 80/20 lube and then on 15% WildCat Premium Extra 15% nitro with 18% 80/20 lube, they both ran exactly the same on both except there was noticably more oil comming out of the breather. I know that isn't exactly scientific, but it proved my point, at least to me. And, I don't think it was my imagination that the gears in both were quieter on the 18% lube.

Fuelman

My Feedback: (6)

FHM 101:
I appreciate your sharing the above info on fine tuning the exhaust pressure line. Maybe with that post, a few folks could really put the theory to work and jump to the next higher level of engine tuning knowledge. I have given that same theory some thought and previously dismissed it as not enough difference in running characteristics after I did my simple test (which of course was not a hard data collection experiment). Thank you for sharing that.


Hobbsy:
I am far less experienced with the RCV engines than the person you are reffering to which operates the RCV USA Service center. However, I have run them extensively in developing fuel blends that best maximize the RCV's potential and have discovered that Otto is absolutly "on target" with his recommendation of a little less oil also, the manufacturer of RCV does suggest lower oil contents than most of the model engine world suggest and this is for a reason. They will tend to experience detonation much easier when using fuels with more oil than they recommend and run hotter. Castor oil is also very important in the operation of these engines, a slight varnish on the piston is necessary for optimal running habits, longevity and power of these engines. This is not to say that runnig the engines on off the shelf high oil fuel can not be done, it can, you just need to be aware of the detonation gremlin and take steps to eliminate it if it creeps up.


Fuelman

tailskid

My Feedback: (34)

Hey Fuelman....it's Jerry here, a long way from Alabama! Moved here about 6 months ago....gotta go, no time for chatting - it's flying time. Oh, did I mention it will be about 70 degrees and sunny today? Too bad about the Michigan weather this time of the year

Jerry Festa

Fuelman

My Feedback: (6)

Nice to hear from ya Jerry.
shoot me an e-mail with your phone number. I would assume you're out of Nitro Scent and Fuel by now.

leandro

what is the most popular fuel for nitro cars and trucks out there?????

Fuelman

My Feedback: (6)

Leandro;
Since you are in the UK, I would not be as familiar with your selections since I'm in the US. Ask around and see who is having the best satisfaction with which fuels available to you.

locolobot

Thanks for all the god information. I just need one more item solved. What is the best ARO to use in my four stroke engines? If I am going to store them for weeks at a time (like over the winter) can that same oil be used safely? I have heard that most ARO's and marvel miracle oil cannnot be safely used when storing your engines over the winter as they soften the silicone seals and gaskets used in the engines. Is this true?

Dr Nitro

locolobot,
Rislone engine treatment works great and almost any air tool oil out there, when you have engines that are not pumped like the YS's or anything like a it. The above listed products work great in your typical OS, Enya, Saito, TT, Magnum and ASP 4-strokes. Just squirt it into the crankcase breather nipple and flip it over to distribute the oil.

If you have a pumper engine, I use Cooper's Formula 49 ARO/PRO, but it is expensive. Otherwise, get some Mobil One or Castrol Syntec, past experience has shown me that they do not cause problems in YS engines.

hatnikman3

Fuelman,

I'v seen Tower hobbies selling 4 stroke blend fuel advertized w/ more oil. I have a new O.S 1.20 that still needs breaking in. I purchased Morgan Omega 10% nitro for my O.S 46 2 stroke (readily available to me) & was wondering if it is OK for the 1.2 four banger. The Omega label says nothing at all about oil content!! From what I have read here, Omega is castor/syth. mix. If Omega is not suitable, could you recommend a fuel for the 4 stroke. Thanks in advance for any info, Nick

Hobbsy

My Feedback: (102)

I have opened engines up after sitting for 5 years with Corrosion X in them and the inside of the engine and the C X look like the day I put it in there.

markcobb

What is the difference between heli 15% and regular 15% and can you run heli 15% in your airplane. Will it hurt the engine.

Bax

My Feedback: (11)

Don't worry about your fuel. Omega 10% 2-stroke fuel in your four-stroke engine is fine. If you set the engine properly, you'll get a lot of good use out of Omega fuel...and you'll only have one kind to worry about.

Tower Premium fuels are advertised as having 18% oil content.

iflynething

im using 15% sin. in a os 46ax wonder if 10% sin- caster would be better and what would be the
diff. ? i run it in a something extra most of the time at half throth .... how should i tune it being that i run most the time at half?

Fuelman

My Feedback: (6)

Thanks for everybodies patience, been a bit busy lately and have not been able to visit the forum.
Bax, thank you for stepping in and answering a question.


Markcobb,
15% airplane and heli fuel for most companies is the same thing. Every company I know of refers to heli blends as being all synthetic. some companies market 4-stroke fuel as all synthetic as well. properly tuned, you should not have a problem running heli fuel in an airplane. Keep in mind that heli fuels do not have castor in them so an ABC/ABN type engine or lapped iron piston/sleeve engine are not best served by an all synthetic fuel.

iflynething,
The 46ax is an ABN type engine, it would probably best be served with at least a little castor in the fuel. Going from 15% to 10% should not pose any tuning difficulties, but it will need some minor adjustments for optimum running.

iflynething

Well, I have noticed that since I switched to Byron, that something about the engine has change.....not for the bad but for the good.....There is just something that makes it seem to run better with that castor oil in the Byron....I have also noticed that I am having alot more oil noticable on the wings when it's cleaning time....

Ron Olson

My Feedback: (1)

Nice FAQ posting that you have here! I was just looking around and found this. Lots of great info.
Enjoyable meeting you last Saturday in Flint and thanks for the Nitro Scent sample.
I'm the Double-Cheeseburger Dude.
I'm going to Extreme and picking up some of your fuel to try in my boats.

Fuelman

My Feedback: (6)

Yes Ron, I remember you. thanks for stopping into the forums.

I was thinking of getting some posts together that would be of benefit to boat racers since they are operating in a unique environment.

Iflyenything:
Glad to hear you have something that is working well for you. Let us know if you need any further info. Bax, thanks again for jumping in and helping out, one of these days I'm going to give you a call.

Fuelman

mkrauser

My Feedback: (2)

Fuelman,

I currently run PowerMaster YS/Saito 20/20 in my Saito 100 4 stroke (aircraft). I asked our local hobby shop if it was OK to run this same fuel in my 2 stroke motors and the answer was absolutely yes. However - I was reading the PowerMaster web site and came across this quote "this fuel is formulated exclusively for 4-Strokes and should not be used in 2-Stroke engines." http://www.powermasterfuels.com/products/4-Stroke.html

It is certainly more convenient to run the same fuel in multiple aircraft engines...

Is it OK to run full synthetic 20/20 in both 2 stroke and 4 stroke engines?

Thank you...MK

Ron Olson

My Feedback: (1)

Most Hobby Shop employees should go back to selling Star Trek junk! Listen to the Saito web site.
Sorry, Fuelman knows who I deal with at my LHS's.

tiktock

hi,

I cant seem to find synthetic oil, is it ok to use castor oil for a saito 91?

Thanks.

Fuelman

My Feedback: (6)

Mkrauser,
Looking at the powermaster site link you gave, the other two blends mentioned on that page are the low oil 4-stroke fuels which should not be run in a 2 stroke. The YS 20/20 should have 20% oil in it.
Running the 20/20, if you correctly tune your two strokes and are not running 2-stroke lapped iron or bushing engines, you should be fine. For the record, I am a firm believer in a little bit of castor for the ABC type engines.

tiktok:
100% Castor oil fuel will gum up the four strokes over time. You can order synthetic oil from several places in the US. Cooper's, S&W, SPL Lubricants and others will ship you synthetic oil.

Fuelman

littlecrankshaf

My Feedback: (58)

Fuelman what can you tell us about Yukon(sp) sythetic oil used in some fuels? I can't seem to find out much about it through a search.

Thanks

Fuelman

My Feedback: (6)

I believe you are refering to UCON which is one of the trade names for a family of fluids from Union Carbide. From my experience, a couple of the UCON fluids were suitable as a lubricant in model engine fuels.
If you are looking for good proven lubricant to make fuel yourself, you can contact some of the model fuel companies and buy what they use. A few of us sell to the home blender. Of the fuel companies out there, myself (Cooper Fuels), S&W and Morgans sell their well proven lubricants to the home blender.

Dart373

My Feedback: (2)

Good post. Thanks for the awesome info. I have been trying to find more about 30% Heli fuel in a .61 ASP 4 stroke. A couple of my guys at the field have been flying for a couple of years now with ASP .61's just like mine on the Cool power Heli Fuel. Is it harmful for these engines? They admit they run them a little rich, but NEVER add oil. 2 Years on 2 motors with nothing more than valve adjustments... I am thinking about switching over. I ran one session on their fuel in mine this week. I did have to richen it up a little bit. It really really ran so much better and had a whole lot better idle qualities. I was running the Omega 4 stroke 10%. What are your ideas here. I only ran 1 tank of it through mine. Thanks.