coolant system, overheating?
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

coolant system, overheating?



At 09:59 AM 4/21/2002 -0700, you wrote:
>I agree that running in the 200 degree plus range won't hurt an engine, if
>the gaskets and seals have been replaced with modern materials in the last
>10 years or so.

DB, there is some possibility that the "overheating" 440 was partially 
rebuilt in the past 20 years, and modern seals were used.  However, it has 
survived the worst.

>The danger comes from localized boiling, which can cause vapor pockets in
>the heads, ...  Uneven heating is what causes warping of heads etc., not 
>simply
>high temperatures.

Actually, excessive temperature can hurt the engine on its own virtue.  The 
heads are hotter than the block, and the differential expansion can damage 
the head gasket, even if no warping takes place.  That's why aluminum heads 
are more venerable.  In my case, the 16 psi cap, the small amount of 
antifreeze, and the rust mad apparently prevented the local boiling that 
you mentioned.  Another problem with excessive temperature is that the oil 
looses viscosity, and the wear rate of the rings can increase.  I am always 
using Mobil 1 15w50 that has very high viscosity index (meaning maintains 
viscosity at increasing temperature) which is perfect for this 
situation.  I even ran the engine at WOT at that condition reaching 
240F.  The car refused to go over 125mph, probably because the super hot 
radiator heated the under-hood air causing loss of air density and thus 
performance.  No engine damage though...  In retrospect, I shouldn't have 
pushed it, but apparently these old 440's are tough.

D^2




Home Back to the Home of the Forward Look Network


Copyright © The Forward Look Network. All rights reserved.

Opinions expressed in posts reflect the views of their respective authors.
This site contains affiliate links for which we may be compensated.