jimmyjames213

My Feedback: (2)

can i run this engine ( http://www3.towerhobbies.com/cgi-bin...?&I=LXHSL2&P=0 ) mag .70 4 banger
with this fuel ( http://www3.towerhobbies.com/cgi-bin...?&I=LXGHP1&P=0 ) omega 5% nitro
and a MAS 13x6 prop
????
i havnt bought the engine yet just wandering if ill need fuel as well (i have a few gallons of ^^^ fuel)

Arceenut

Engine will run on this fuel but you might find it a little easier to tune for idle with a little more nitro (10% -15%)

Jetdesign

My Feedback: (8)

I think the requirements for the engine are poorly worded on the website. It looks like they're not suggesting a total oil content, rather a percentage ratio of castor to synthetic oil. It says that the recommended fuel is Powermaster 10% (not carried) so Powemaster 5% should be just fine.

I believe there is a "Club Magnum" or something like that in the Glow Engines forum. I'd hang out there and read about what others are using for fuel for future use.

Last summer I tried switching between 10% and 15% nitromethane, and really only noticed a difference in fuel consumption and maybe a slight change in power. With 5% nitro you will use less fuel, probably not notice a difference in performance, and maybe have a little less room for error in tuning (noticeable?).

I also switched brands of fuel toward the end of the season, and the newer brand had 20% oil content, which means 2% less methanol content, and thus less energy. I really felt I noticed a decrease in power, but not sure how much of it was do to the change in energy content and how much was do to a different manufacturer's fuel.

As a side note, increasing nitromethane does not mean an increase in energy. Nitromethane acts as an oxidizer in the fuel, meaning you can increase the fuel to air ratio in the engine, and thus burn more fuel for more power.

bkdavy

My Feedback: (1)

The identified engine is a ringed engine. Magnum recommends for their ringed engines that your fuel contain no more than 10 percent nitro and at least some castor oil. The low nitro number is to prevent preignition on the high compression engines. The castor is recommended in order to varnish the ring and cylinder walls. This will further improve the compression of the engine as it breaks in.

The coolpower fuel contains all synthetic oils, and will not give you the varnish the castor will. I run the Morgan Fuels Omega 10 in my magnum engines. It has about 2-3 percent castor, the rest synthetic.

Brad

Jetdesign

My Feedback: (8)

I'm pretty sure it's just the green Coolpower that has no castor. The fuel in the link has a high percentage of castor oil, and is pink.

Gray Beard

My Feedback: (-1)

5% works just fine but you may either have to run a bit higher idle or adjust the low end so it will idle smoothly. Idle is about the only thing anyone would notice running 5%.

jimmyjames213

My Feedback: (2)

i think morgan and coolpower are the sames fuel, green is all synthetic, pink it a synthetic/castor blend

i run 5% because i dont need more power, at all. i run at half throttle 80% of the time, i only increase when i go vertical.
also if i idle a little higher its no big deal, as long as it is reliable. i have a guy at my field that knowes engines inside and out, he should be able to get it to idle nicely.

Gray Beard

My Feedback: (-1)

Then by all means run 5%, why spend the extra money. I tested the 5%, 10%, 15%, 20% then the 30% all using a YS 1.10 and an OS 1.20 and the idle was the only thing that changed at all. All the fuel tested was Power Master except for the 30% and that was a brand of Heli fuel. I run the 15% myself but that's just because I have always gotten it at a good price. All the fuel I tested was a gift from an old modeler that had it under his bench for years and was just getting rid of all his stuff and getting out of the hobby. So much for that old age fuel thinking too.

Clay Walters

Here's what the Magnum folks say:

http://globalservices.globalhobby.co...ic.php?t=21074

Regards,

Clay

Campgems

The color is not a good indicator any longer. I stoped into the LHS a couple weeks back to pick up fuel and almost picked up Cool Power rather than the Omega I burn. I'm not sure when the changed the color of the Coolpower, but it now comes in pink. Going to have to pay closser attention to the lables.

I differ with some of the post earlier, 15% nitro Omega is what I've been running for the last three years in my four strokes, most are Magunm, but an O.S thrown in. The lower nitro hurts the idle, expecially if the engine is inverted. I like the castor/synthetic blend of Omega. I've pulled down s couple engines after crashes and the rust is a myth. They may be some red stain on parts, but because it is red doesn't make it rust.

All personal preferences aside, most of the fuel today will work without damaging engines.

As long as this can of worms is open, I'll add this. I never pump fuel back into the jug. At the end of the day, I cap off both fuel lines to the tank and what is left stays there until the next fly day. If the weather look like I may not get out in a few weeks, I fill the tank and then cap the lines. What I've been bad about not doing is putting the plastic plug back in the jug, I've just put the fill line back into the top of the cap. If I've been slugish about draining a jug, say a couple month or more, the last couple tanks don't idle as well in my 4 strokes. Thats about the extend of it.

An aside, When I was first starting out, my instructor was a full synthetic oil guy. Every time I had issues with the engine, he would make quips about "I smell castor" or the likes. Once I learned to tune engines, he still smells my castor, while I'm flying and he is tuning. Bottom line, what works for you, keep usning it.

Don