Castor vs Synthetic - 4 stroke problems

Castor vs Synthetic - 4 stroke problems
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Castor vs Synthetic - 4 stroke problems - 5/23/2003 7:55:38 PM

GPutt33

Posts: 760
Joined: 5/29/2002
From: Sheridan, WY, USA
Status: offline

Hi all - I am new (only a little over a full year) and have gone from my LT-40 with an OS46 FX in it to my SIG 4 Star 60 with a SAITO 91.

The other day at the field I was told that the blend of 80% Castor to 20% Synthetic could be bad on my 4 stroke and make the exhaust valves stick after awhile. I was then shown the brown crude building up around the exhaust on the muffler. I thought this was normal for a little discoloration to start showing up.

Suggestion was that I go to an all synthetic fuel. What are everyone's thought's on this.

Also suggested I could drop to a 10% from 15% nitro and then only have one fuel for both engines.?

I don't know enough about it yet to tell the difference. I have 2 more gallons to go through before I need to buy more.

Thanks for any advise you can give me.

_____________________________

****** Gregg******
Rule one: No matter what else happens, fly the airplane.
Rule two: Fly it until the last piece stops moving.
You know you've landed with the wheels up when it takes full power to taxi.

Post #: 1

Castor vs Synthetic - 4 stroke problems - 5/24/2003 12:50:01 AM

hauckf

Posts: 188
Joined: 3/1/2002
From: Decatur, AL, USA
Status: offline

Try [URL]Saito-engines.info/fuel.html[/URL] . This is NOT an official Saito site, but a site run by someone with a lot of experience with Saito engines. Lots of info, should answer at least some of your questions.

(in reply to GPutt33)

Post #: 2

Castor vs Synthetic - 4 stroke problems - 5/27/2003 9:58:51 AM

Fuelman

Posts: 1017
Joined: 12/31/2001
From: Jordan, NY, USA
Status: offline

G Putt,
You stated:
"The other day at the field I was told that the blend of 80% Castor to 20% Synthetic could be bad on my 4 stroke and make the exhaust valves stick after awhile."

Over time, 80% castor / 20% synthetic fuel could cause (and most probably will) some varnishing up of the valves and ring land on a 4-stroke. This will be worse the hotter or leaner the engine is run.
If you are using a fuel with 80% synthetic and 20% castor (reverse of what you mentioned), you will not experience a severe varnishing problem. An 80/20 synthetic to castor blend would be just fine for most sport flying when properly tuned.

"Suggestion was that I go to an all synthetic fuel. What are everyone's thought's on this".

An all synthetic fuel is fine for 4-strokes and is quite common these days.
If you want one fuel for both of your engines, a synthetic / castor blended fuel is probably your best alternative.
A fuel with an 80/20 to a 90/10 ratio of synthetic to castor when the total oil amounts meet or exceed the manufacturers warranty requirements, will be fine for both your Saito and your 46FX when correctly run. That little bit of castor in the fuel will give you plenty of additional benefit for what little discoloration it causes on a muffler.

< Message edited by Fuelman -- May 27 2003 6:02AM >

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(in reply to GPutt33)

Post #: 3

YS 20/20... - 5/27/2003 5:40:45 PM

glowplugboy

Posts: 580
Joined: 12/26/2001
From: Pasadena, TX 77505/77508, TX, USA
Status: offline

I would suggest going to your favorite brand of YS 20/20 blend fuel. "20/20" stands for 20% nitro and 20% all synthetic oil content. I haven't had a four stroke yet that didn't like the nitro and oil content of this "blend" designed to cover YS's warranty requirements. Byron's is great, but then again, I am a dealer for Byrons.

Regards,
GPB

(in reply to GPutt33)

Post #: 4

Opinions are like ******** - 6/3/2003 6:36:11 PM

jimo811

Posts: 54
Joined: 1/29/2002
From: Orange, TX, USA
Status: offline

Everyone has one. Go to your local field and see what everyone else is running, how much time they spend tweaking their engines, or how they seem to run in the air for them. I have acquired several engines over the years that were run with castor based fuels and after time, they are difficult to even turn over with the prop due to buildup inside as well as outside. I have ran CoolPower 15% fuel in every glow engine I own, and I add about 2 oz. of Klotz oil to each gallon, and all engines run great. I spend no time at the field setting or playing with my engines. I come to the field to fly, and with this fuel combo and proper initial settings, that is what I do. I run Saito 180's, OS46FX's, Supertigers, YS's anything, and they all run great.

(in reply to GPutt33)

Post #: 5

Castor vs Synthetic - 4 stroke problems - 6/3/2003 7:03:54 PM

downunder-RCU

Posts: 1125
Joined: 12/27/2001
From: Adelaide, South Australia
Status: offline

Well here's another opinion.
You guys in America must have some really bad castor over there. It takes me years of running before I'll even consider taking an engine apart to clean it and that's with 20% all castor

Not owning a 4 stroke though I'll reserve judgement on the best oil for them.

(in reply to GPutt33)

Post #: 6

Castor vs Synthetic - 4 stroke problems - 6/12/2003 1:32:32 AM

flapbreaker

Posts: 205
Joined: 1/16/2002
From: OR
Status: offline

The Castor vs synthetic "debate" is an interesting one. I too recently go into 4 strokes. I have a Saito .91 that runs great on 10% cool power (100% synthetic). But when it comes to fuel you will get all kinds of advice. Here is what I have come to understand.

Castor oil provides protection at higher temps than synthetic so theoretically the 4 strokes will benefit by having some Castor oil in the mix. In fact the Magnum 4 stroke engines say they should be broken in with a fuel that has Castor in it since the engine will run hotter with 100% synthetic.

There is also a new trend at my flying field, and someone mentioned it here and that is people are starting to add extra synthetic oil (aka Klotz) to their fuel. Not sure how this started or why people feel that more is better. Maybe someone here can address that.

As far as Nitro is concerned, the four strokes don't need very much since their power doesn't come from high RPM but from torque. The 10% should work fine for you 2 stroke unless you are flying something high performance.

Hope this doesn't confuse you to much. Otherwise just fuel them up and go fly. If the engine runs great with what you are using don't feel obligated to change anything.

(in reply to GPutt33)

Post #: 7

Castor vs Synthetic - 4 stroke problems - 6/15/2003 11:53:44 AM

Richard L.

Posts: 8775
Joined: 7/28/2002
From: Redmond, WA, USA
Status: offline

Here is an excerpt from Wilcat Fuel site:

quote:

Wildcat recommends the lubrication package be totally synthetic. The use of synthetic oil is important in four stroke engines to prevent gumming and varnishing of the lifters and coking of the valves. Varnishing will occur on castor based fuels. This can lead to sticking valves, which will cause the valve set to get knocked out of time. Coking of the valves will cause improper seating of the valves causing a reduction in compression and incomplete combustion. Four stroke engines also have high exhaust gas temperatures and the use of synthetics greatly reduces carboning at the exhaust ports.

Read more about it here: [URL]http://www.wildcatfuel.com/fuel_24cycle.html[/URL]

(in reply to GPutt33)

Post #: 8

Castor vs Synthetic - 4 stroke problems - 6/20/2003 2:16:52 PM

Flyboy Dave

Posts: 13375
Joined: 3/20/2002
From: San Bernardino County, CA, USA
Status: offline

quote:
--------------------------------------------------------------------------------
Wildcat recommends the lubrication package be totally synthetic. The use of synthetic oil is important in four stroke engines to prevent gumming and varnishing of the lifters and coking of the valves. Varnishing will occur on castor based fuels. This can lead to sticking valves, which will cause the valve set to get knocked out of time. Coking of the valves will cause improper seating of the valves causing a reduction in compression and incomplete combustion. Four stroke engines also have high exhaust gas temperatures and the use of synthetics greatly reduces carboning at the exhaust ports.

Man, that's a riot....

I especially liked the one
about the "valve set....getting knocked out of time"..... :

We certainly wouldn't want that to happen....

_____________________________

An engineer says.... "That won''t work".
A mechanic says..."Oh yeah, watch this".
"Old Age, and Treachery will overcome youth and skill".
Revver Bro #4.

(in reply to GPutt33)

Post #: 9

Castor vs Synthetic - 4 stroke problems - 6/21/2003 8:19:13 AM

Wildcat Fuels

Posts: 79
Joined: 2/22/2002
From: Kentucky
Status: offline

Flyboy Dave,

When I write information to the end user I have to take into account the user and various experience levels of the modelers. To state that the engine is "knocked out of timing" is just short-hand. I have ghost written many articles for various magazines on engines and glow plugs over the years and many other well respected names also simplify their statements to a laymans level. Although, the intention is to point our draw backs of castor based fuels in four strokes the technical aspects could be better explained and will be addressed in the near future. Thank you for pointing this out.

Jerry

(in reply to GPutt33)

Post #: 10

Jerry.... - 6/21/2003 9:42:23 AM

Flyboy Dave

Posts: 13375
Joined: 3/20/2002
From: San Bernardino County, CA, USA
Status: offline

....thank you for the information.

Richard L. posted the "quote" from the Wildcat site....
and truthfully I didn't go to the site to check it out....

...but the thing is, you know alot of people come to this
site, and to the internet in general to get information. A
person unfamiliar with engines and fuels could garner this
from that post....

I you put castor oil in a four stroke motor, this can happen:

engine gumming....
varnishing of the lifters....
coking of the valves....
sticking valves....
valve set knocked out of time....
improper valve seating....
reduction in compression....
incomplete combustion....
carboning at the exhaust port....

Sounds like pretty bad stuff....

....personally, I've not
experienced those evils from using some castor in my
engines....but I only started running the four strokes about
14 years ago....and have been using the same brand of fuel
throughout.

Thank you for your reply, Jerry....

Flyboy Dave.

_____________________________

An engineer says.... "That won''t work".
A mechanic says..."Oh yeah, watch this".
"Old Age, and Treachery will overcome youth and skill".
Revver Bro #4.

(in reply to GPutt33)

Post #: 11

Castor vs Synthetic - 4 stroke problems - 6/21/2003 10:16:34 AM

Wildcat Fuels

Posts: 79
Joined: 2/22/2002
From: Kentucky
Status: offline

Dave,

I am glad you have had good sucess with what you have been doing. All of the things listed can and does occur in four strokes. The largest service centers biggest issue is the de-coking of motors returned for service. Like you I have been doin this for a while, around thirty years, and I have seen a few gummed up engines. Granted, not everyone experiences these problems, mainly due to experience in setting up a motor properly and not over leaning the motor. Since we manufacture for the many and not just the few we recommend what we know works the best in this application.

Jerry

< Message edited by Wildcat Fuels -- Jun 21 2003 5:58AM >

(in reply to GPutt33)

Post #: 12

Jerry.... - 6/21/2003 10:45:42 AM

Flyboy Dave

Posts: 13375
Joined: 3/20/2002
From: San Bernardino County, CA, USA
Status: offline

....well said. And I always say...."if it works for you....
stick with it". I have my 30 year hashmark also. One
thing I don't do....is bash any fuel brands....

....I will, however discuss the properties of different
types of oils.... :

And FWIW, I don't think I've ever heard anything bad
about Wildcat....

Good luck to you in your endeavors....

Dave.

_____________________________

An engineer says.... "That won''t work".
A mechanic says..."Oh yeah, watch this".
"Old Age, and Treachery will overcome youth and skill".
Revver Bro #4.

(in reply to GPutt33)

Post #: 13

Castor vs Synthetic - 4 stroke problems - 6/21/2003 10:48:58 AM