Small Four Strokes and Nitro.
#26
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I may take the time to test both fuels on my larger engines. I was tempted to buy the 20/20 blend but it's $15 more. Go figure. I don't see the point in paying $15 for 2% more oil. Since the 20/18 was the same price as the lower nitro. I decided to try it and I've used about four gallons this summer. I add a little castor and burn it in my 1/2 A engines. The biggest surprise for me was that the OS ran away from the Saito on a 9X6 but on the 10X6 any small mixture adjustment could likely make them equal. I would guess 13,100 RPM is getting into valve float range on the OS. In my opinion if you're going to run that kind of RPM you might as well use a two stroke. I assume the lower nitro effectively oils more due to the greater volume entering the larger needle valve opening.
#27
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Both of these engines are an engineering marvel in my eyes. The Saito is well used but I think the test was quite fair because the OS is not completely broken in. If anything I set the OS a little more to the rich side. As for the price of glow engines the scale follows quite directly with displacement. I sometimes wonder if the larger, more expensive engines are less expensive to actually build. The machine work on a .30 has to be more difficult than it is on a 1.80 for example.
#28
I may take the time to test both fuels on my larger engines. I was tempted to buy the 20/20 blend but it's $15 more. Go figure. I don't see the point in paying $15 for 2% more oil. Since the 20/18 was the same price as the lower nitro. I decided to try it and I've used about four gallons this summer. I add a little castor and burn it in my 1/2 A engines. The biggest surprise for me was that the OS ran away from the Saito on a 9X6 but on the 10X6 any small mixture adjustment could likely make them equal. I would guess 13,100 RPM is getting into valve float range on the OS. In my opinion if you're going to run that kind of RPM you might as well use a two stroke. I assume the lower nitro effectively oils more due to the greater volume entering the larger needle valve opening.
#30
It will likely be more noticeable on a 2-stroke than a 4-stroke but indeed the mixture will need to be richer on more nitro. I suggest running 10% first, tach it to peak and shut it down. Empty the tank or switch tanks and run the 20% nitro and get the tach on it. I'll bet it will pick up a few rpm if you richen the needle from the peak setting on 10%. The "sweet spot" of the needle valve will be wider on more nitro so it may seem misleading as the rpm likely won't sag per sé on less nitro as the the higher nitro gives you a few more clicks of wiggle room on the needle. When I compare fuel mixes like this, I take note of how many clicks a given engine has rich to lean on each fuel I test.
#31
As for the Saito numbers the 20% didn't yield a whole lot more power on either prop.
Still the OS did even better on 10%
#32
It is when one increases the Nitro level that one also, usually, have to open the needle valve. With a higher nitro contents one will empty the tank faster...
#36
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On My OS 30 i have ran it over 14,500 on a 9x6 prop with an aftermarket carb. You can get the carb and carb manifold off the 30 car engine. they even have HD springs for it if you would like to run in 20,000 rpm range. But for most planes that will use this engine that is to high as i think i had to run a 7x6 prop to get that high. Now an 8x4 at 19,000 might pull well too. So in short in the two engines I messed with they were fine in the 14,000 range on the stock springs.
#37
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I flew for several hours today using both engines. I stand corrected. The higher Nitro fuel does require a slightly richer needle setting. I had it backwards on my original notes.
#39
It's been raining for 3 days here in Minnesota.. Just mixed up a half gallon of FAI fuel to break in an engine but alas the weather blows. Today it's supposed to stop raining but the wind speeds are said to be 25-35mph.
#40
#41
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I have flown in a slight drizzle but not in a full blown rainstorm, I worry too much about my electronics getting wet. If you mean my Saito 62 its on hold as I am busy with helping out some adopted kids
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I just ran my little .30 on the 10% with 18% synthetic, I think it likes it.
Saito .30
Prop==Bolly 10x5.5
Fuel==WildCat 2/4 10% with 18% synthetic
Max rpm 10,250, more stable shown on tach
Idle was very smooth==2,200= a little
Plug===Taipan 4c.
Saito .30
Prop==Bolly 10x5.5
Fuel==WildCat 2/4 10% with 18% synthetic
Max rpm 10,250, more stable shown on tach
Idle was very smooth==2,200= a little
Plug===Taipan 4c.