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Oil Selection F134

Discussion in 'Early CJ-5 and CJ-6 Tech' started by kenb, Mar 12, 2019.

  1. Mar 14, 2019
    Keys5a

    Keys5a Sponsor Sponsor

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    Call me old fashioned! Like I mentioned, the F134 is an old design engine with loose tolerances compared with "modern" engines, including your '77 Jeep engine. The 134 has a crazy long stroke, and big wide bearings to take the load. This design was from the days when thick oil was needed. This engine dates back to the 1930's. The engine hasn't changed, but oils have. Modern multi-weights are quite thin at startup, and in my opinion, not optimal for our old design engines. I have no issues with running a high detergent oil. Keep in mind that the spin-on filter (introduced around '64) is only a bypass filter, not full flow. Again, its not like those on a modern engine. Modern oils sheet off of the interior surfaces in a week or two. The old non-detergent clings for years protecting interior surfaces from large temperature swings that can cause condensation inside, so that is what I consider an advantage if you are in a high-humidity area.
    I don't want to start a huge debate on oils, so I just giving my opinions and why I use what I do. Others will have their views that might not agree with mine, and thats fine too.
    -Donny
     
  2. Mar 14, 2019
    kenb

    kenb New Member

    Detroit
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    Thanks for the reply. To be clear, the 1977 dated Jeep service manual I referenced with the 10w30 spec was listing that for the F134 engine. The manual covers 53-71 Jeeps. I'm still not sure how cold weather cranking ability vs being thick enough when it's cold. Complicated stuff
     
  3. Mar 14, 2019
    70cj5134f

    70cj5134f Member

    East Tn
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    In old design engines, it was common practice to run a summer
    Oil and a winter oil. But with modern oil u don't have too.
    I do like running thicker oils in my classics 10-40 or thicker, and
    I add stp or Lucas which thickens it even more, and adds cling to the oil.
    Bout the coldest I ever have to start was 18deg. It normally stays inside but shop
    was full. Turned over a little slower than normal, but with choke at max, it fired
    right up. I let it run 5-10min then off I went.
    In colder climates, I'd do the seasonal oil change?
    Ps-ever read a 40s-50s owners manual?
    Some recommend the seasonal oil change, and diff oil, and tranny oil.
    My 58 VW bug recommends tranny seasonal change.
     
  4. Mar 14, 2019
    Keys5a

    Keys5a Sponsor Sponsor

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    It is interesting to see 70cj5f134's brass government dash tag states above 32 degrees, 30W oil, and below 32 degrees, 10W oil. That's on a 1970 model.
    -Donny
     
    70cj5134f likes this.
  5. Mar 14, 2019
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    I'd use the 10W30 and regard the oil pressure. You need enough oil pressure to maintain the oil film in the bearings, typically spec'd at a minimum of 10PSI for every 1000 RPM.

    Modern multivis oils are no different from single weight oils in most respects. They all thin out at high temperature and thicken at low temperature. The muti-vis just gets less thin when hot and less thick when cold, but only when it's new. As the oil ages, the mutivis character deteriorates, so when you drain old oil from a hot engine, I expect you are seeing the thinness due to the worn-out multivis character of the oil. Synthetics are better in this respect.

    I use 15W40 Rotella or Delo dino oil in all my Jeeps. Seems fine, but I don't drive them when the weather is really cold.
     
  6. Mar 14, 2019
    Rick Whitson

    Rick Whitson Detroit Area Sponsor 2019 Sponsor

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    I use 30wt like the book says, I only run my Jeep in warm weather so I can get away with straight 30wt. I like Kendall oil, I have used it for years in my four stroke motorcycles, and was always impressed how clean they were inside when torn down.
     
  7. Mar 14, 2019
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    I know, apples to oranges, but I've always liked the chart in the owners manual for my Honda dirt bike.

    [​IMG]
     
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  8. Mar 14, 2019
    PeteL

    PeteL Member Sponsor

    Hills of NH
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    That's fine, but some our Jeeps were built before Honda was a thing.

    Very very different engineering.
     
  9. Mar 14, 2019
    colojeepguy

    colojeepguy Colorado Springs Sponsor

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    It might not leak so fast with non synthetic oil. I've run into this with several vehicles. Synthetic oil flows better, whether it's through the engine or through a leaking gasket!
     
  10. Mar 14, 2019
    Mcruff

    Mcruff Earlycj5 Machinist Sponsor

    Albertville, AL
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    Honda’s been around since 1946, in 1948 it was incorporated. Honda has given the world some incredible engineering during its time.
     
  11. Mar 14, 2019
    PeteL

    PeteL Member Sponsor

    Hills of NH
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    Not saying otherwise. But radically different mechanical philosophy. High rpm, for just one example.

    And Honda's first production automobile wasn't until 1963.

    So I'm hesitant to accept automatically their advice on lubricating vehicles gestated in the 1930s.
     
    Last edited: Mar 14, 2019

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