The only thing I've ever heard that is a flat out no-no is to use detergent
oil in an engine after it has had non-detergent oil in it for quite a while.
Any good brand oils (Quaker State, Castrol, Shell, etc,) should work well
together. It isn't supposed to hurt to mix oil weights, if you still are
within the weight applications for your uses. I don't know abt using
synthetic oils with non-synthetic oils. I asked Castrol abt the drain interval
with synthetic oil. They said the same as standard oil, but you have more
protection. I used to know a gent in the navy who used to run a quart of
kerosene through his cougar engine (spark plugs out to allow easy turn-over)
with the starter prior to putting in new oil. He would drain the old oil, take
out the spark plugs, put in the kerosene, run the engine with the starter,
then drain the kerosene. Then he would put in a quart of new oil, run that a
few seconds to flush the kerosene. Next he would install a new filter, fill
the engine with oil, and re-install the spark plugs. He changed his oil at
3000 miles. I have never done this (kerosene flush), as I change the oil in
my cars at (abt) 3000 miles, and think this is enough. But if I had an old
engine I didn't know the history of, I'd consider flushing the engine. There
are also fluids made just for flushing engines, available at the car parts
stores. Just use a really good brand oil. And change the oil often. There are
even services that will analyze your oil, and tell you what components in the
engines are wearing, based on what metal traces are in the oil. Aircraft
owners (and the military) have been doing this for years. Well, my soap box is
starting to totter, so that's abt it. Bob K in PHX,AZ
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|