How much castor??
 

I am using cool power 10% and 15% and I want to add some castor to it. What would be the appropriate amount to add?

RE: How much castor??
 

Morgan fuels typically have 17 or 18% oil in'em. Can't quite remember which, but no matter. 128 oz in a gallon of fuel, and we'd like to bring it up to 20-22% total oil, typically. If you're flying only "normal size" engines, then 20% is entirely adequate (actually, so probably is what's in there to begin with, but this is about insurance, not current needs). If you fly anything 1/2a, 21 or 22% would likely be better. Since we're looking to add 3-4% total oil (.03 x 128 = 3.84), 4 oz would be about right for a gallon, or 1 oz to each quart.

J

RE: How much castor??
 

HI I add 2 oz. to every gal. of fuel. That is a little less than 2 percent.

RE: How much castor??
 

Irish,

I usually add 2 ounces of Sig Castor to every gallon of fuel, both Omega and Magnum (which is what the two hobby shops I usually deal with carry). I fly both plain bearing and ball bearing engines with the same fuel and want to make sure the plain bearing engines are well protected.

Hogflyer

RE: How much castor??
 

There are some online spreadsheets and java applets out there which will help you out but I don't have my links here in the office (it's lunchtime).

What engine are you using and in what type of application? I'm a old control line flyer and have always used either all-castor or a generous blend of synthetic/castor. Even my modern OS ABN engines (such as the FP or LA) like 22% total oil. The 17% or 18% RC fuels just don't work well for that application.

When I fly RC with a ABN or ABC ball bearing engine, I like at least 18% total oil with at least a 80/20 synthetic/castor ratio. Wildcat Premium Plus fits that requirement perfectly.

RE: How much castor??
 

When I add castor I figure in bumping the total oil up to about 20%, erring on the side of more oil.

128oz fuel at 18% total oil has 23.4oz oil. Adding 4oz castor to a gallon of fuel gives you 27.4oz oil, and a total oil content of 20.75% (85%synthetic, 14.6%castor).

Don't forget that adding oil also reduces nitro content, though not by a noticeable difference. If you have 10% nitro fuel, and add 4oz of oil, you end up with 9.55% nitro.

This is pretty convenient, at least for me, as Price Chopper sells 4oz bottles of castor oil for $2.75.

*note: someone above talked about running OS engines on 2x% oil; the manual does say MINIMUM oil content of 18%, so I agree that 2x% is pretty good.

RE: How much castor??
 

Why not just buy omega?

RE: How much castor??
 

I will next time, but I have 3 gallons of cool power. I run 52 to 180 4 stroke and 46 to 75 2 stroke. All 4 stroke magnums and OS 2 stroke

RE: How much castor??
 

I add extra castor to Omega too. Why? Because Omega also only has 18% total oil, part is castor. That's not enough to make me feel comfortable when running (especially) 1/2a engines on.

Goirish, with your mix of engines, I'd tend to squeeze towards the 20% mark, not much higher. 4 strokes can be sensitive to excessive oil content. It impacts their tuning, or so I've read. Still saving for my first 4 stroke.....

J

RE: How much castor??
 

I throw a splash of Castor in my Wildcat Extra, too, just for peace of mind.

RE: How much castor??
 

You can order a gallon of caster for about $28. 4 oz at $2.75 comes out to about $88 a gal. we just order two gallons and split it.