Oil comparison

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The Tropics of Antartica
From the same site , their take on thin oils and cylinder glazing from oxidation in which is something I have not heard of until reading this " . Thin oils contain base stocks that are relatively light (about 25C’s). The lighter the chains are the higher the tendency is usually to under oxidation, this being a loss of electrons, or in simple terms, a change in the oils ultimate function, usually a deterioration. Thin oils can cause a “glazing effect” in the cylinders of pushrod type motors and those that also rev relatively slow. Although the glazing effect is strongly dependent on the metal composition of the cylinder an the type of oil that is being used. Glazing is where the cylinder has effectively gone ultra hard and just like super heated metal, it gets a pearly glazed appearance on inspection. Once this glazing has occurred, then oil consumption will increase as will emissions of white smoke and the compression and hence power will decrease. This is a problem often seen with 80’s –mid 90’s Mitsubishi engines. What causes the glazing?? Well, the glazing effect is caused by the premature oxidation of light HC chain molecules and the hardening of the metal surface of the cylinder wall. Thin oils are more susceptible to oxidation if constant heat is not supplied to the oil in the piston ring/cylinder setup. For example, 1.8l Honda motor that revs out to 9000rpm will satisfy the heat requirements, unlike a holden motor that revs out at 5500rpm. Even if both engines held at the same revs, the smaller capacity will always have more heat generated between the rings and cylinder, for more contact is experienced over the same area over time. More often than not, old design motors that have been designed around mineral based oil will experience this phenomenon more often than not in the long term. "
 
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Ephraim
quote:
Originally posted by Motorbike: Even if both engines held at the same revs, the smaller capacity will always have more heat generated between the rings and cylinder, for more contact is experienced over the same area over time.
Maybe maybe not! would you say that the SEATING of the rings based on a good break-in would more than likely ADD say at least 1/3 - maybe even at least 1/2 the problem? I can see faster is more heat, or can be, but I donno about the rings issue...>
 
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