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What is ''normal'' DD 71 series oil pressure?

Discussion in 'Technical Discussion' started by cleanslate, Jun 4, 2019.

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  1. cleanslate

    cleanslate Senior Member

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    Been meaning to report back with hot idle oil pressure....Starboard 18 or so psi, port 12 or so psi 700 rpm. Thank you all for your input.
  2. rtrafford

    rtrafford Senior Member

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    Replaced all gauges and senders, Murphy switches at engines and lower helm. These buckets of steel will always scare the hell out of you with oil pressure ratings. You drop to idea, and they'll drop to zero. They don't generate a bunch of oil pressure because, as I understand, they pump bucket fulls of oil up top and let gravity rain it down. Critical is the temp. If they're running cool, they're getting oil. If they're running hot, you'll be running for a loan.
  3. rtrafford

    rtrafford Senior Member

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    And that's good pressure for the 12's. Also watch for oil consumption. They eat when they aren't leaking.
  4. cleanslate

    cleanslate Senior Member

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    Both engines burn a little less tha a quart of oil on a 10 hour 1500/2000 rpm day.
  5. cleanslate

    cleanslate Senior Member

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    I just installed two mechanical oil pressure gauge is at the engine .
    Got them both along with the fittings for $20 each at the automotive store .
    I did have to purchase two 1/8” tees and two close 1/8” nipples, $15.

    I ran a hose clamp behind the mounting bracket on the gauge and clamped both gauges to the oil filler tube on the engines . Done deal ! Yay works great. $55, and 1 hr time to install.
  6. cleanslate

    cleanslate Senior Member

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    48EECF9F-593D-4470-9BE7-9F38236FE4D6.jpeg
  7. rtrafford

    rtrafford Senior Member

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    Chevron Delo 100. Rotella, a terrific oil, will see the consumption increase. Stick with Chevron Delo 100 for these old DD71's.
  8. Capt J

    Capt J Senior Member

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    I too prefer either Chevron or Mobil oil for the old DD's. I too have noticed that Rotella drops a lot of oil pressure (hot) and consumption goes up once it gets 50 hours on it with the old 2 strokes.
  9. rtrafford

    rtrafford Senior Member

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    Yes, all of this. Truck mechanics tell me that the lower levels of ash content in the Chevron Delo 100 is the difference maker. I took their word for it and saw a difference worth paying attention to...
  10. Capt Ralph

    Capt Ralph Senior Member

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    I've been pushing the NAPA fleet CF-2 oil for years in Two Stroke Detroits. Part number 75118.
    Have no idea about the ash. Always been very happy with it.
    There is always a NAPA store close by.
  11. rtrafford

    rtrafford Senior Member

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    I've read forums where the ash content was shown as the underlying component of a trend towards better longevity of the Chevron Delo 100. I know that's not a scientific explanation, but it does appear that there is at least some science to this. Lower ash amongst 40 weights......
  12. cleanslate

    cleanslate Senior Member

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    It's Valvoline 40 weight in a blue NAPA 5 gallon pail, btw. I'll give it at try if the price is right.
    I don't see a difference with any of them, . I always run straight 40 weight, I've use Rotella T1; Pennzoil ; Chevron Delo 100 all with good results.
  13. Capt Ralph

    Capt Ralph Senior Member

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    I did not realize Pennzoil offered a CF-2 oil.
  14. rtrafford

    rtrafford Senior Member

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    The Napa CF2 is Valvoline, and it’s low ash, .80%. Rotella is 1%. DD want low ash content.
  15. cleanslate

    cleanslate Senior Member

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    CR ! Yup I used it . my mechanic got it for me I still have the bucket in the bilge for old oil and fuel I’ll take a look and double check the ratings .