Castor oil for Cox

Matt1967 Tue May 28, 2013 2:51 pm

I was under the impression that Cox engines need 100% or nearly 100% castor oil in the fuel mix.

Tower Hobbies shows that the Cox brand 1/2a fuel contains: This is the quart (946ml) Bottle of Super Power 1/2A Fuel from Cox.

FEATURES: Premium blend 25% nitro formula is ideal for model airplane, car, or
boat use
Special 18% oil package consists of 90% synthetic, and 10% castor
lubricant blend

What's the deal?

**RknRusty** Tue May 28, 2013 3:50 pm

I just looked at the tech notes on that.
http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXDBNH&P=8#otheritems

Cox engines are long known, dating back to Leroy Cox to need more castor than that. I've never been sure exactly how much oil, some say 17% and others say 20%, but always at least half of that must be castor. There's never been any disputing that among Cox employed engineers or just plain Cox expert users. I thought I remembered reading the Tower Cox notes before and seeing a reasonable mix, but maybe I was mistaken. I sure wouldn't run that stuff in my Cox engines. Or any brand of small 1/2A size engines. They spin too fast and hot not to have a good supply of castor.

fredvon4 Tue May 28, 2013 4:51 pm

The Tower hobbies HCAP2900 I bought a while back (in pints only) is not offered any more

May be what you remember Rusty:

Search of the product has this tech note

"This is a 1/2 pint of Hobbico Super 1/2A 25% Nitro Fuel.

FEATURES: Designed for 1/2A category of model airplane engines, and Cox model
airplane engines, as well as boat and car engines
Special Klotz oil formulation helps lubricate and cool engine
components
25% nitro offers benefits such as more RPM, better throttle response,
smoother idle, and reduced needle valve sensitivity compared to
15% nitro fuel
18% lubrication content"

Because it was %18 lube I add a wee bit of Sig Castor...no formula..I just add an oz or three...

I had assumed the Klotz was mostly if not all Castor blend because they reference Cox model engines

JKinTX Tue May 28, 2013 6:46 pm

If you want it to last- castor is king. It isn't just the ball and socket at the piston; except in a few cases the case itself is the main bearing material and a steel shaft turning several thousand RPMs without an adequate cushion effect wears REAL fast.
If you like your motor- keep the castor and a generous level as well.

JK

dckrsn Tue May 28, 2013 8:10 pm

Well put JK.
Also welcome to the forum.
Bob

Mark Boesen Tue May 28, 2013 10:04 pm

Welcome to the forum JK!

Like they say, never Assume.

This subject was brought up last month on the .049 Collectors site.

Hobbico owns the rights to the name 'Cox' and can put it on a can of Bull Sh*t if they think it will sell. The fuel formula is basically R/C car fuel. Apparently the 1/2a market is too small to mix up a big batch of fuel, yet potentially profitable to whip up some labels.

If you want you engines to last you need about 20% oil with 17-20% being caster, to run more your performance will suffer, to run less the engine will.
Castor oil for Cox Fuel10

coxaddicted Wed May 29, 2013 5:36 am

JKinTX wrote:If you want it to last- castor is king. It isn't just the ball and socket at the piston; except in a few cases the case itself is the main bearing material and a steel shaft turning several thousand RPMs without an adequate cushion effect wears REAL fast.
If you like your motor- keep the castor and a generous level as well.

JK

I guess this is a good point too. My cox does not run on full speed every time because it is build in a rc car. In the 90ies rc car fuel was based with some castor but not enough. I didn't had the problem with the ball and socket due to limited rpm's but the engine case was worn out very quickly (much fuel leaked out between prop-plate and casing).

I didn't thought about this point yet btw: i am using the correct ammount of castor since i have signed in here (Thank you Forum).

The manual of my Kyosho car says only : use Car Fuel with minimum 16% Nitro.

For the next winter I will spend this destructed engine case a ball bearing for the crankshaft.

dinsdale Wed May 29, 2013 7:06 am

I mix my own:
25% nitro
12% Klotz castor oil
8% Klotz synthetic oil
The remainder methanol

My engines go forever - one at least has been well used (abused) for 15 years, and that's nearly forever Laughing

**RknRusty** Wed May 29, 2013 10:48 am

That sounds like a good healthy blend, Dins.

JKinTX Thu May 30, 2013 7:11 pm

coxaddicted wrote:
JKinTX wrote:If you want it to last- castor is king. It isn't just the ball and socket at the piston; except in a few cases the case itself is the main bearing material and a steel shaft turning several thousand RPMs without an adequate cushion effect wears REAL fast.
If you like your motor- keep the castor and a generous level as well.

JK

I guess this is a good point too. My cox does not run on full speed every time because it is build in a rc car. In the 90ies rc car fuel was based with some castor but not enough. I didn't had the problem with the ball and socket due to limited rpm's but the engine case was worn out very quickly (much fuel leaked out between prop-plate and casing).

I didn't thought about this point yet btw: i am using the correct ammount of castor since i have signed in here (Thank you Forum).

The manual of my Kyosho car says only : use Car Fuel with minimum 16% Nitro.

For the next winter I will spend this destructed engine case a ball bearing for the crankshaft.

Your English is better than my German is- and half my family hails from there, and some of the extended family specimens still are there.

JK

coxaddicted Fri May 31, 2013 5:10 am

Your English is better than my German is- and half my family hails from there, and some of the extended family specimens still are there.

JK[/quote]

Thank you Very Happy

! I do my best. I had english in school over a decade ago. Beside my interest in cox engines, this forum is a ,,training'' to become not rusty in this language.

fredvon4 Fri May 31, 2013 5:19 am

I took the plunge and ordered a gallon of Nitro and a gallon of methanol from E-bat Torco yesterday

High priced but free shipping

My search locally (no close racing or speed shops) found some technical Nitro but at a horribly high price for a 5 gallon can ..$327.99

Is there a compelling reason to order up some Klotz?

...I have a few quarts of Sig 100% Castor Oil

Planning to formulate for 15% 25% and 35% in quarts, all with 20%~22% oil

Wish I could find Pint or Quart Metal Cans with opening in end instead of center

Moisture and light are the killers and metal cans are the preferable storage for me

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