Which would be the better fuel to use a 15% Synthetic or a 15% Synthetic
Castor Blend
- posted
18 years ago
Synthetic vs Blend
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- posted
18 years ago
Which would be the better fuel to use a 15% Synthetic or a 15% Synthetic
Castor Blend
===========================
You'll get equal opinions for either choice.
Simple safe answer - use what your engine manufacturer recommends.
Some fuel companies say use blend for ABC engines and synthetic for ringed engines.
Magnum four strokes are ringed and the book specifically calls for castor in the fuel or you have no warranty. Saito four strokes are ABC or AAC and they recommend Cool Power Helicopter fuel which is all synthetic.
I like synthetic oils. My engine is a Thunder Tiger 61 Pro which is ABC/ABN, and the instructions call for castor oil. I do not run the engine extremely lean and it runs just fine with synthetic. The slime is easier to clean off of my plane than when I used blended oil.
Simple safe answer - use what your engine manufacturer recommends.
Some fuel companies say use blend for ABC engines and synthetic for ringed engines.
Magnum four strokes are ringed and the book specifically calls for castor in the fuel or you have no warranty. Saito four strokes are ABC or AAC and they recommend Cool Power Helicopter fuel which is all synthetic.
I like synthetic oils. My engine is a Thunder Tiger 61 Pro which is ABC/ABN, and the instructions call for castor oil. I do not run the engine extremely lean and it runs just fine with synthetic. The slime is easier to clean off of my plane than when I used blended oil.
- posted
18 years ago
Depends on the engine and type of use.
-- Paul McIntosh
-- Paul McIntosh
- posted
18 years ago
Morgan's, among others, recommends a blend for ABC/ABN engines, and straight
castor for ringed or lapped iron engines. I've always followed this, and
haven't have any trouble.
Dr.1 Driver
"There's a Hun in the sun!"
- posted
18 years ago
Straight castor for ringed engines? Not likely. They recommend straight
synthetic (Cool Power) for ringed engines. I wouldn't recommend straight
castor fuel for anything other than old iron piston, steel liner engines.
-- Paul McIntosh
-- Paul McIntosh
- posted
18 years ago
Interesting. My preference has always been castor/synthetic for ringed
engines as well, though this is based on one particular experience. A friend
of mine and I were running an ST .35 (broken in) on synthetic and it was
unhappy no matter how much time was on it, needle fiddling etc. We switched
to castor/synthetic blend, same mfg, same nitro content, and the motor
immediately changed it's character totally, running stronger, consistently,
throttling, idling better etc.
Beats me what other factors could account for that, but to us it was apples to apples and the difference plain as day.
As to straight castor - I agree, no way. That I would tend to think is one of those archaic "play it safe" manufacturer's suggestions harking back to lapped engines. Has it not been demonstrated by many knowledgable engine people that a certain percentage of castor is sufficient to provide the benefits without the horrors associated with pure castor?
Mike D.
Beats me what other factors could account for that, but to us it was apples to apples and the difference plain as day.
As to straight castor - I agree, no way. That I would tend to think is one of those archaic "play it safe" manufacturer's suggestions harking back to lapped engines. Has it not been demonstrated by many knowledgable engine people that a certain percentage of castor is sufficient to provide the benefits without the horrors associated with pure castor?
Mike D.
- posted
18 years ago
Yup. That dates back to when Fox said use their fuel or void your warranty.
Dr.1 Driver
"There's a Hun in the sun!"
- posted
18 years ago
Mainly because if you DIDN't use their fuel, you would likely ruin their
engines! They were so crudely made that they needed the 25% castor to keep
the parts from grinding together.
-- Paul McIntosh
-- Paul McIntosh
- posted
18 years ago
We Ran all castor ( because thats all there was at the time ),in all our Mcoy
and ETA ringed engines and never had a problem. I tried using it in a new
Saito 130 twin and it did not like it at all. In my first YS120 i used a blend
of 3% castor and 12% synthetic and never had a problem with sticking ring or
carbon build up,motor ran for years on the original bearings and ring. DOUg
- posted
18 years ago
Agreed...we ran all castor in our ETA's, McCoy's, Doolings, MS29's...you
name it. I ran 25% all castor in my Enya 45 for more years than I can
remember and still use 25% in my ST G51. Not once have I ever had this
so-called stuck ring problem. I use all castor in my ABC, ABN and AAC
engines (all 2 strokes) because I KNOW it works.
- posted
18 years ago
I never had the stuck ring problem either, but the goop is certainly there.
I have had to devarnish cylinder internals before though. I quite agree with
the benefits of castor oil, but I'm pretty convinced that using a percentage
of castor is sufficient and gives you some of the benfits of both types. I
use 50/50 blend (20% total oil) in my 1/2A's and they run like a champ. I
use lower percentages of castor in larger engines.
Mike D.
Mike D.
- posted
18 years ago
They weren't crudely made! Well OK the needles and carbs were, but
the rest of the engines were well made. I have a Fox Stunt .35 that I
have ran 100% synthetic oil on. Ran OK but hard to start afterward,
not that the engine was overheated, its just that the thinner
synthetic doesn't provide enough compression seal.
- posted
18 years ago
IMHO FOX engines were/are a "Curate's Egg" - meaning some parts are
excellent. Others.. well.. ;-)
My old Hawk .60 ran like a bear, er, hawk. I liked the look of the tapered cylider fins, like that matters running-wise..
Mike D.
My old Hawk .60 ran like a bear, er, hawk. I liked the look of the tapered cylider fins, like that matters running-wise..
Mike D.
- posted
18 years ago
IMHO, the 'stuck ring' problem came from lean runs that burned the
castor in the ring groove.
David
David
- posted
18 years ago
Castor has a lot higher flash point than synthetic oil. we used
castor when thats the only oil for models, in ringed engines and never had a
stuck ring. I used some Cool power 30% heli fuel which is all synthetic in a
YS 63 4 stroke and after 3 gallons the valves were totally coked up with burnt
on oil. DOUG
- posted
18 years ago
They were about the most crude looking engines I have ever owned. That says
nothing about how they ran. All of mine ran great, once you understood
Dukies' methodology.
If the synthetic oil was too thin, then there was WAAAAAAY too much clearance.
-- Paul McIntosh
If the synthetic oil was too thin, then there was WAAAAAAY too much clearance.
-- Paul McIntosh
- posted
18 years ago
You didn't use the recommended fuel. What do you expect?
-- Paul McIntosh
-- Paul McIntosh
- posted
18 years ago
The only Fox engines that required castor oil was the lapped iron
piston models. Duke claimed that the lifetime warrenty was void if
synthetic was used on any of his engines. That didn't mean that they
would not run on synthetic oil. He just did not like synthetic oil. I
have a Fox Eagle from the 70's that I run occasionally on Omega fuel,
that about 30% castor and 70% synthetic. It runs about as well as my
K&B .61 and about the same weight but can be tricker to tune. Oh,and
the finish is ugly.
- posted
18 years ago
I had an Eagle IV .74 that almost refused to run on anything but Duke's Fuel
(10% nitro and 20% castor). Ran great on it and ran terrible on
Powermaster.
-- Paul McIntosh
-- Paul McIntosh
- posted
18 years ago
It is rather strange that I got a gallon of Duke's Fuel that has a
sticker on the top stating "100% synthetic". I still have the can
with that sticker!
David
David