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Running cutting oil through the cooling system to keep it from rusting?

deejaycee_2000

deejaycee_2000

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Hi guys, I was wondering ... I use soluble cutting oil on my lathe at home and thought this might actually work. I have the 4.3L Mpi with open cooling system, even though I only use it on fresh water I always open up the 7 point draining system so it can dry out between weekends when not in use ... What is your opinion on running the same lathe cutting oil in a bucket through the cooling system before storage, this way it will coat the internals en wash right out with the next use?
 
Fist off...... I would not be interested in doing this myself.
Secondly, I would want to know if this oil would be chemically compatible (or non-compatible) with the material used for my seawater pump impeller.


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Ayuh,...... Why,..??..??

Yer motor will last longer than you will, if yer worried 'bout rust-thru,......
 
The block is nodular iron with additives that make it very resistant to the kind of flaking deep rust scale that you see on regular cast iron parts like the exhaust manifolds. The exhaust manifolds are actually a wear item that need replacement at regular intervals. Since they heat cycle thru a huge range, oiling the innards won't help much as the protection will fail pretty darn quick.
 
Wow, South Africa. I have to say that without any seawater in your cooling system, I wouldn't worry about rust. High quality cast iron used in most marine engine blocks is 10 to 20 percent nickle. There is a code on many GM blocks that indicate the minimum nickle content. I prefer a 20 percent in engines I build for race and marine. At 20 percent, GM often adds 10 percent tin, which is also okay. Although slightly less porous, perhaps, the nickle adds a margin of strength as well as corrosion deterrent.
In my opinion, keep the oil out of the cooling system, it will more likely negatively affect any rubber composition components, brother.
 
Interesting opinions, thanks guys! The main reason I started to worry about this is the amount of rusty water that comes out when I drain it. A few weeks ago I replaced my impeller on my alpha one gen 2 and there were big stones of rust that came out when I dropped the lower unit. So I assume I will need to replace my manifolds and risers very soon. I have the dry joint assembly. Temp is still running constant with no issues.
 
Got 9 seasons out of a pair of dry joint MERC OEM elbows on my boat that spends 5 to 6 months a year in salt water. My system is set up to be easily flushed any time I want to. In my case, I flush it with freshwater every couple of outings and with salt away once or twice a season. Before storing for the winter, I do another fresh and saltaway flush and then run anti freeze thru it. The system has a heat exchanger, so I'm only dealing with the heat exchanger itself and the elbows, not the block or manifolds. There was NO evidence of serious degradation on the elbows after 9 seasons, but I replaced them anyway.
 
That is exceptional maintenance, brother. I work on navy vessels when they call me....out at Charleston. The salt water damage is simply incredible. On the great lakes here, they stay so sweet.
 
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