What are this white spots on the cylinder.
#1

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Location: Illinois, USA
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Hey guys, I disassembled my engine today to do some clean up and to check the state of it. When removing the cylinder I found this white spots (they look yellow in the pictures but those are white),



Those weren't there 4 weeks ago when I reassembled it after the cleaning because it was stored for more than 10 years, also they feel smooth.
I have been looking around the internet but I haven't found any info. I have a theory that is probably rust from the crankshaft that was already there when I bought this car 14 years ago in Colombia, the previous owner had the car stored for 5, I used it for about 1 year, and I stored it for 10 because of a couple broken parts and in Colombia back in those days the parts where no easy to get and too damn expensive. The crankshaft now looks almost pristine, the fuel manage to remove 90% of the rust (Torco Air 20% Oil 25% Nitro-methane) that probably went up to the combustion chamber and some how attached to the cylinder. The engine is the OS Max 12 CV and I ran 6 tanks after the cleaning, the last run was today and before that 10 days ago. As extra info, I checked the glow plug, it have the right grey color, and the coil is not deformed or anything and still glows great. The engine continue to work flawless but I had to tune it again (lean the mixture) because of the weather change. (from 45F ~ 55F the last 3 weeks to 90F today). The piston is clean it doesn't have any spots on it. The body of the engine looks cleaner and the bearings are running much much better with this fuel (I fell in love with it). Also when I disassembled the engine I didn't find any debris inside.
I just hope those white spots doesn't mean anything wrong.
Thanks for the help.



Those weren't there 4 weeks ago when I reassembled it after the cleaning because it was stored for more than 10 years, also they feel smooth.
I have been looking around the internet but I haven't found any info. I have a theory that is probably rust from the crankshaft that was already there when I bought this car 14 years ago in Colombia, the previous owner had the car stored for 5, I used it for about 1 year, and I stored it for 10 because of a couple broken parts and in Colombia back in those days the parts where no easy to get and too damn expensive. The crankshaft now looks almost pristine, the fuel manage to remove 90% of the rust (Torco Air 20% Oil 25% Nitro-methane) that probably went up to the combustion chamber and some how attached to the cylinder. The engine is the OS Max 12 CV and I ran 6 tanks after the cleaning, the last run was today and before that 10 days ago. As extra info, I checked the glow plug, it have the right grey color, and the coil is not deformed or anything and still glows great. The engine continue to work flawless but I had to tune it again (lean the mixture) because of the weather change. (from 45F ~ 55F the last 3 weeks to 90F today). The piston is clean it doesn't have any spots on it. The body of the engine looks cleaner and the bearings are running much much better with this fuel (I fell in love with it). Also when I disassembled the engine I didn't find any debris inside.
I just hope those white spots doesn't mean anything wrong.
Thanks for the help.
Last edited by Mr.Alvaro; 05-24-2018 at 11:56 PM. Reason: Some grammar corrections.
#2


The nickel plating in/on the cylinder is peeling off due to poor manufacturing. This is a common problem with OS engines nickel plating technology. Use the engine while it runs okay, and plan to toss it afterward. The only way to repair it is to replace the piston/liner or have the liner stripped and re-plated. The former will be expensive due to parts availability and the latter even more because the best way to re-plate is with hard chrome and that is expensive due to many parts of the world not allowing it due to environmental concerns with pollution.
#3

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Sh** It is going to die sooner than expected. I am going to order the new engine and start to work on the mod for the slide carb. I just hope that the engine don't die until I get the 3D printer.
#4

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I would not run that engine in a plane at all
You have worn out the engine as you are looking at the brass layer of metal coating under the old piston liner that is nickel
When this starts to happen it will cause heat issues and could knock out the glow plug
You are looking at a dead stick situation so why chance that
Sell the engine for parts that someone could use
It is not cost effective to replace the liner when a new replacement engine is a better investment than putrchasing the cost of a new liner
Flying only Glo for 23 years
Enjoy
You have worn out the engine as you are looking at the brass layer of metal coating under the old piston liner that is nickel
When this starts to happen it will cause heat issues and could knock out the glow plug
You are looking at a dead stick situation so why chance that
Sell the engine for parts that someone could use
It is not cost effective to replace the liner when a new replacement engine is a better investment than putrchasing the cost of a new liner
Flying only Glo for 23 years
Enjoy