I am thinking about getting a glow helicopter and already own an glow airplane. I Know that you must get differeant fuels for each. My question is WHY? What is the difference between the two and are they interchangable? Any help is Appreciated.

Most (but not all) heli-fliers run higher nitro than is normal for fixed-wing planes, partly because they want more power and partly because there's a belief that higher-nitro equals lower running temperatures.

Some heli-fuels also have a higher oil content to provide improved protection given the more limited cooling and greater loads that heli-engines tend to endure.

You don't *have* to get different fuels for each -- most heli-engines will run just fine on as little as 10% nitro and many fixed-wing engines will run fine on as much as 20%-30% nitro.

I fly my heli with any fuel I have laying around. I just tune accordingly.

Slap a Venom temp recorder on your Heli (They are cheap at tower) and see the difference for yourself. I can't speak for the 30 size stuff but it sure makes a difference on the OS Hyper in my Raptor. To clarify a little what happens is you tune the heli richer on 30% giving you about the same power overall (Slightly more) but the extra fuel keeps the temp down. If you run it leaner like you would on 15% you can pick up power but the temps will be up as well. There is less air flow coming from the fan as compared to a prop and the airstream while in flight on a plank. On 30% my Hyper runs between 200 and 210 at 2000 rpm's head speed. (17,000 engine r's) I didn't have the Venom when I was running 15% in it, but I assure you it was running way hotter. When I would shut it down after a flight it would be smoking; it doesn't do that on 30%.

Also, most heli fuels do not contain any castor oil in the mix. They use 100% synthetics, mainly because the castor tends to varnish at the higher temps which could stick the rings and it also leaves brown stains on their big shiny mufflers.

On a ringed (heli) engine, fuel with no castor is tolerable but if you don't run castor in an ABC or ABN plane engine you run the risk of destroying the piston and liner with a lean run.