Originally Posted by Rafael23cc
If you think price is worth more than aggravation, go ahead. You will quickly learn one of two things. You will learn to properly and accurately tune a nitro engine, or you will learn to heed advise from people that have been doing this way longer than you. Do you want to fly? Or do you want to experiment?
On the other hand, if you are worrying about nitro price, this hobby might not be for you.
Sorry if I was harsh. But the reality cannot be covered with a blindfold.
Or get an electronic ignition system. You can get rid of ALL Nitro without fear of heat issues, without any tuning issues (you still need to tune but it is VERY easy).
The ignition system will typically compensate for at least 10% Nitro, AND it will save you even MORE fuel. (the fuel saving from fitting a CDI is approx equal to changing from 25% Nitro to 0% Nitro, but with only half the power loss)
Fitting the CDI needs to be done as you see fit for your particular helicopter.
Ignition timing has to be set at 34 degrees.
Fuel: just use 0% Nitro, and either 20% Castor, or 15% full synthetic
(or whatever your taste might be in lubricants, don't want to start a discussion here, fact is, you can reduce oil content by in cases as much as 1/4 compared to glow ignition)
Tuning is easy: Give your engine one or two tankfulls to adjust to the new lubricant content, gradually leaning out a one or two clicks at a time. After that, turn in the main needle until the power drops in a punch-out. Back out main needle 2 clicks and never touch it again.
Close midrange needle until power drops in hoover. Open it slightly and never touch it again.
Close idle needle until engine idles smoothly. leave it at that.
No need to do acceleration tests: the engine WILL accelerate immediately when you open the throttle, regardless of fat or lean idle (too rich, it dies, too lean, it dies, but over a wide range, the engine will pick up regardless of mixture)
You will see, that despite much lower oil content, and much leaner carb setting, you can still touch the backplate for 10 seconds immediately after a hoover.
You can (if you can reach it) even touch the heatsink for several seconds after that hoover.
When running 30% Nitro with glowplugs, for example an RCExl system will have paid for itself within 2 or 3 gallons of 0% Nitro fuel....
It will have paid for itself after approx 10~15 broken glowplugs too.....
At least, that is my experience (non-3D).