ORIGINAL: opjose
ORIGINAL: Gray Beard
Other then a little more tuning on the low end they all worked pretty good in my four strokes. The idle was a bit rougher with the 5% but I'm sure if I spent a little more time on it that wouldn't be any problem. The few added RPM I get with the 20% and 30% isn't worth the added cost. They are easier to tune with a higher nitro fuel though.
That is exactly what I've found as well.
There is quite a hike in fuel prices going up to 15%-30% compared to the lower nitro contents.
Many of the magazines have gone into nitro requirements, and the findings are that higher nitro serves best on the fairly small engines. .40 and below.
I've only used Castor on an engine or two, where it was recommended for break-in.
Other than that I run all brands without it to good effect.
BTW: The articles also discuss that as displacement increases oil content percentage requirements are lessened and will even rob power.
I had a friend that no longer flew and he had gallons of different flavors under the bench he wanted to get rid of. Free fuel, no problem!! That was why I decided to do my own testing. I was always told that the high nitro fuels were made for those that didn't know how to turn the needles, seems there is a lot of truth in that. I did get more RPMs out of the 30% but the couple of hunderd wasn't worth the added price. The engines did idle better or were easier to adjust, again, at what price?? Maybe if I was flying pattern or something? The 5% did give a rougher idle and I didn't bother fooling with it. I ended up blending the 5% with the 20% and the engines were all happy with it. All I need now is some more free fuel or a really good sale. Brand to brand I haven't seen any difference either. I fly with four strokes in glow engines, a mix of OS and YS with an odd Saito tossed into the deal every so often. Don't you just love seeing how a YS just has to have 30% or they won't run.
They did OK on the 5%, not as well as the OS engines but OK.