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WFE
12-21-2002 20:25:08
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Re: Re: Re: Re: 1855 Gasser in reply to Adam Suess, 12-21-2002 14:53:03
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Good info, Adam. As I have been taught, electrolysis is a phenomenon which can occur in all engines, but is most common in diesel engines and modified gasoline engines under higher compression ratios. It helps to imagine a wet sleeve engine with coolant in the water jacket surrounding the sleeve. During the ignition of the fuel (the power stroke of an engine) intense force is created in a small period of time resulting in a shock wave if you will. This shock wave is transmitted to the wall of the cylinder/sleeve (as well as the piston of course). The shock waves from the several ignition cycles that occur every second result in the sleeve resonating. It is a very small and rapid movement, but it is occuring, again particularly in diesel engines and higher compression gasoline engines in which the ignition is more powerful and violent. Anyway, as the sleeve resonates, the coolant surrounding the sleeve does not have enough molecular adhesion to maintain contact with the sleeve as it is resonating. As a result, tiny air pockets are formed around the sleeve which form and burst in the blink of an eye. As these air pockets burst, their effect, over time, will result in the pitting and eventual weakening of the materials with which it comes into contact, be they cylinder sleeves or sleeve counterbores or block gussets, whatever is resonating as a result of the detonation of the fuel to a significant extent. The use of coolant conditioners (silicate additives) or coolant rated for diesel engine applications which already has the necessary conditioners, alters the chemistry of the coolant to increase its adhesion to the sleeve, preventing the air pockets from forming and subsequent electrolysis damage. I have removed sleeves so weakened by electrolysis that they literally crumble when removed from an engine. Then again, there was a 310 I did a while back that had 4600 original untouched hours on it and the sleeves were in great condition. Owner changed coolant regularly.
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