[NSRCA-discussion] After run oil?

[Lance Van Nostrand]

Careful John, Marvel oil will thicken and eventually turn pretty hard, and 
be difficult to remove.  This takes several years of storage though.

The OS140 burns bearings faster than the OS160 so less precautions are 
needed for the 160.  Let me repeat what I've found after getting 
non-repeating results with other methods.  Run the engine on FAI (no nitro) 
fuel for 30 secs at the end of the day.  1/2 the corrosion problems are due 
to the combustion byproducts sitting in the engine (nitric acid is from 
burning nitro).  "rinsing" in this way and letting the engine get hot/up to 
temperature both flushes the nitric acid and coats the engine in oil.  The 
heat evaporates any methanol so there are no hygroscopic materials left.

Doing this will give consistently good results.

--Lance
----- Original Message ----- 
From: "John Ferrell" <johnferrell at earthlink.net>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Wednesday, May 09, 2007 1:46 PM
Subject: Re: [NSRCA-discussion] After run oil?


> Marvel Mystery Oil for Air Tools has a rust inhibitor.
>
> John Ferrell    W8CCW
> "Life is easier if you learn to plow
>       around the stumps"
> http://DixieNC.US
>
> ----- Original Message ----- 
> From: "Tom Simes" <simestd at netexpress.com>
> To: "NSRCA discussion" <nsrca-discussion at lists.nsrca.org>
> Sent: Wednesday, May 09, 2007 12:26 PM
> Subject: [NSRCA-discussion] After run oil?
>
>
>>
>> The list is a little quiet this morning, and I'm troubleshooting a
>> possible delivery issue with AOL, so I thought I would lob in a question
>> likely to spur some discussion :)
>>
>> For years I was in the "just run the fuel out and put it away camp".
>> However, I had the occasion to send an engine back to OS because the
>> cylinder plating had failed.  To their credit, they replaced the whole
>> engine gratis, even though it was a year out of warranty.  Their only
>> comment on the receipt was to make sure I was using after run oil.
>>
>> I don't think the plating failure was caused by not using after run, but
>> I do know that I replaced bearings in that engine very early in it's
>> service life and there was internal rust after < 2 gallons through it.
>> At the time I put in stainless bearings and didn't worry about it
>> further.
>>
>> Some things I *think* I know about after run oil....
>>
>> Hobbico AR is Marvel Mystery Oil (MSDS documents are the same) and it
>> has no particular anti-corrosion properties.  My understanding is it's
>> basically a combination of solvents in a light carrier oil.
>>
>> Silicone components in some engines (YS) may be damaged by some commonly
>> used AR oils.
>>
>> ATF seems to be popular and has good anti-corrosion agents.
>>
>> Rislone also seems to be popular - like MMO, lots of solvents but with
>> some added anti-corrosion agents as well.
>>
>> Synthetic oils (Mobil 1) seem to be safe for all engine
>> components (including YS?).
>>
>> When OS says in their instructions not to put AR oil in the carburetor,
>> they are specifically referring to not putting it through the needle
>> valve / spraybar.  Putting AR oil in via the carb barrel is fine, and
>> something like 1/4 - 1/2 tsp is an appropriate amount.
>>
>> So, if you are using after run oil, what kind are you using and how do
>> you keep it from making a mess in your field gear?  I've been using
>> Mobil 1 5W30 and applying it with an eye dropper, but I'm looking for
>> suggestions.
>>
>> Thanks
>>
>> Tom
>>
>> ======================================================================
>>   "Z-80 system stack overflow.  Shut 'er down Scotty, the system's
>>         sucking mud" - Error message on TRS 80 Model-16B
>>
>> Tom Simes                                       simestd at netexpress.com
>> ======================================================================
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