I was wondering if anyone knew the general temp range when the AL parts of the engine will start to brown due to overheating?

 

"AL"????????????

Are we supposed to guess what that is? "Aftermarket Lighting"?? "Aluminum Linkage"?? "Ambient Liquid"??

 

Sorry, beyond the capitalization of the L I was hoping people would recognize it as the element symbol for Aluminum. So for any further clearing up let me throw some more info in. When the aluminum housings brown on the bottom side it is said to be caused by the engine overheating. Does anyone know at what temperature range this occurs at?

 

Don't know when it the housing would brown but 1220.666 °F is the melting point

 

The browning is probably from the oil either being dirty or getting "baked" on. If you ever disassembl a motor with some miles on it, lots of the parts have a brown residue on them.

 

I agree that it's oil dirt. Aluminum is known for being rather invisibly hot - very hot aluminum looks just like cold aluminum (unlike steel which glows at some point around 900F).

A wire brush and some engine cleaner/degreaser should cut into that ugliness a bit.

Dave

 

On a couple motors I've seen this browning on the bottom but currently I'm seeing it on coolant passages in the housings and the thermostat housing and was wondering if was from the same thing.

 

That is probably corrosion since it is in the coolant passages. Or more dirt.

I think the temperature is largely unrelated to the browning.

-Max