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F Head Oil Survey

Discussion in 'Early CJ5 and CJ6 Tech' started by kenb, Feb 17, 2023.

  1. kenb

    kenb Cleverly disguised as a responsible adult

    What kind of oil is everyone running in their F head? I have been using VR-1 10W30. The issue I've noticed is that in the hot part of summer I get oil pressures a bit lower than I like after extended driving. I'm considering trying Rotella 10W30 to see if that does better.
     
  2. Jw60

    Jw60 That guy 2024 Sponsor 2023 Sponsor 2022 Sponsor

    I ran 10w-30 Castrol GTX in my f134
    I tried something else in the 4.3 and it ran hot so it's Castrol GTX 10w30 and some additives when I remember (85 with flat tappets and towing cam)
     
  3. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    10-30 house brand from my FLAPS, but I add ZDDAP zinc.
     
  4. Dave Deyton

    Dave Deyton Member

    10W-30 Castrol also in mine. Rotella in the Kubota diesel.
    Time to change the oil in the M38A1's now. Got the oil and filters.

    Dave
     
  5. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Rotella.
     
    tcfeet likes this.
  6. oldtime

    oldtime oldtime

    Rotella 10W40
     
    dozerjim likes this.
  7. Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

    Straight 30wt from Tractor Supply same as I use in my older tractors. I buy it in the gallon jugs, and I also add the zinc additive.

    Good 10-30 oil is probably a better choice in colder climates than the sunny South, but my oil pressure is fine cold or hot.
     
    Rick Whitson likes this.
  8. 59cj5

    59cj5 Member

    Rotella 30w. I only drive in the summer.
     
    Ol Fogie likes this.
  9. compostwerks

    compostwerks Sponsor

    30W, non-detergent, Rotella. Year round and my oil pressure does not fluctuate.
     
    Ol Fogie likes this.
  10. jeepdaddy2000

    jeepdaddy2000 Active Member

    I live in a temperate climate and run multi vis dino in all my rigs with the exception of the wires Z3M. I prefer Rotella 15/40. You can even run it with wet clutches like your quads and motorcycles.
     
    Ol Fogie likes this.
  11. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I use straight 30 wt. but don't drive my Jeep in the winter. Same as my small air cooled motors.
     
  12. kenb

    kenb Cleverly disguised as a responsible adult

    Thanks for the replies. I'm curious for those of you choosing a 40 wt oil, why are you going heavier than the book calls for?
     
  13. oldtime

    oldtime oldtime

    My cheap appropriate oil of choice is Rotella 15W40 No such thing as 10W40.
    I choose that because at the time I contacted Rotella (a couple years ago) they claimed the 15w40 had the highest levels of ZDDP for all their oils. It’s still up around 1200 ppm. I estimate 1200 ppm
    As minimal. Other Rotella viscosities may be more like 1100 ppm.
    With any milt- viscosity oil the base oil is onlh as thick as the lowest number. The upper number is used to show protection provided from addatives.
    So 15W 40 is actually 15 W viscosity and the additives provide protection as the heat from friction raises.
    Around these parts (St Louis) we oft see summer temps over 100* . So 40 wt is appropriate.
    However the 15 wt base is s as lil thick when it drops below 10*.
    In your area you may be better off with a 10W30 viscosity.
     
    Last edited: Feb 18, 2023
    ojgrsoi likes this.
  14. jeepdaddy2000

    jeepdaddy2000 Active Member

    Shell makes a T5 semi syn 10/40
    [​IMG]
    Many of the modern multi vis oils weren't available when the "book" was written. Oil back then didn't have many standards and the selection of straight oils put the 30WT as the go to weight. As stated, personally, I like either a 10/40 or 15/40 and Rotella seems to have the highest zink levels. I also like the diesel additives, especially for engines that sit for longer periods of time. You can also choose some of the "high mileage" oils as well.
    [​IMG]

    Given older engines don't run the tight tolerances of modern mills, a slightly thinner oil for startup and cold climes with a slightly thicker mix for operation at temp seems to be the ticket.

    Colder weather can push you into a 5/30.

    My briefly owned Tundra ran a 0/20 oil. It poured like water. I literally had to do research for peace of mind before I did the oil change.
     
  15. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Just to throw a wrench in the works... (do we have an emoji for that?).

    I grew up hearing that older (well used) engines should use Non-Detergent oil, and I often follow that rule. ND seems doesn't seem be available in multigrades so I'd use SAE30.


    :watch:
     
    Rick Whitson likes this.
  16. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Yes if they haven't been running detergent then you don't want all the built up crud breaking loose & plugging passages up but I'd say there's very few engines around these days that fit that description, pretty much everything from the per-detergent era has had a rebuild or got dosed with detergent a long time ago.
     
    Ol Fogie likes this.
  17. Jw60

    Jw60 That guy 2024 Sponsor 2023 Sponsor 2022 Sponsor

    With aircraft you don't add detergent oil unless provided with the aircraft on rental by the owner. The issue is if you add detergent oil to a non detergent base it can free up crud and cause issues. Also aircraft weights and octane are on different scales much like a 30w is not the same as a straight 30.
     
    Ol Fogie likes this.
  18. oldtime

    oldtime oldtime

    I don’t think the T5 has the same ppm as T4 but not fully up to date on their current specs.
    So I run this in both F-134’s and D225’s.[​IMG]
     
    Ol Fogie likes this.
  19. kenb

    kenb Cleverly disguised as a responsible adult

    I went with Rotella T5 10W30. Couldn't find any current data on the exact specs so I figured I would go for a semi synthetic. Will see how it preforms this summer.

    How much oil are you putting in the engine? My service manual says 4qt, add 1 more with a filter change. If I add 5 it shows over full on the dipstick. I have a vertical spin on filter, not sure if it's draining back to the pan after shutdown and that's why it shows high.
     
    Ol Fogie likes this.
  20. Greevesman

    Greevesman Member

    Local speed shop sells Brad Penn 30 wt. They claim it is good for flat tappet motors. It is green.