Announcement

Collapse
No announcement yet.

zinc in motor oil?-gctid816337

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    zinc in motor oil?-gctid816337

    Another thread got me thinking about this again. Last spring, I went to buy Mercruiser 25-40w oil for my mercruiser gas engines at the local marine store. The owner was there and he said that about a year ago, Mercruiser had changed the formulation of their motor oil so that it no longer had zinc in it. He said it was because of concerns it could interfere with the proper operation of the catalytic converters in new marine engines. He recommended Sierra 25-40w marine engine oil as it has kept the zinc in its oil formulation. Makes sense as zinc is very important especially in salt water and the zinc in the oil helps to protect the internal metal engine parts as well. I went with Sierra as they are about the same price anyway. First time I had heard of this and curious what others think about it.
    1998 3587 Bayliner, Port Orchard, WA

    #2
    "baylineguy" post=816337 wrote:
    Mercruiser had changed the formulation of their motor oil so that it no longer had zinc in it. He said it was because of concerns it could interfere with the proper operation of the catalytic converters in new marine engines.
    It was an EPA mandate to reduce phosphates in all oils, and the zinc and phosphorus were used as anti-wear ingredients. The phosphorus also combines in newer cat-equipped motors and clogs them up. You can buy additives that replace it where needed.
    Custom CNC Design And Dash Panels

    iBoatNW

    1980 CHB Europa 42 Trawler- "Honey Badger"

    Comment


      #3
      Zinc in oil was an anti-wear additive as SS states. Back when I was building my truck engine, zinc free oil was fairly new and people were experiencing a high number of wiped cam lobes on new engine builds during break in. It was mostly on engines with aggressive cam profiles and higher than stock spring pressures. The fix at the time was a zinc additive or to use diesel engine oil for the break in period.

      I wouldn't worry about it in your motor, as long as there aren't any reports about engine failures due to the new formulation.
      . . .It places the lotion in the Basket. . .and that basket happens to be in a 1987 Bayliner 3870 w/ Hino 175's

      Comment


        #4
        http://pqiamerica.com/

        Go here and dig. You'll learn more about oils than you ever thought to ask!

        Comment

        Working...
        X