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Used sportfish decisions

Discussion in 'Bertram Yacht' started by Mike Hall, Apr 20, 2009.

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  1. K1W1

    K1W1 Senior Member

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    Hi,

    What CAT's have u got?

    How high are the actual PPM Levels?

    Measure the Crankcase pressure when you run it for 5 hrs, if you got cylinder problems then you will have blowby and raised pressure

    Is it a single or twin installation?
  2. Mike Hall

    Mike Hall New Member

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    It is a twin installation with 3208/435hp. The readings are 60 iron and 12 aluminum on #1 and 50/9 on the other one..thanks.
  3. K1W1

    K1W1 Senior Member

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    Hi,

    Do you know what is in your oil when it's new?
  4. Marmot

    Marmot Senior Member

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    I would check with CAT and ask them specifically about that engine and its expected lifetime fuel burn. Their standard number for maximum wear metals is around 100ppm for iron and 15 for aluminum. But taking a single analysis alone without information regarding the trend and oil consumption, doesn't tell you much.

    An engine that consumes a lot of oil dilutes the wear metals so they read lower in analysis. An engine that is really worn might have polished liners and rings that no longer wear much metal off the surfaces. I would be suspicious about not being allowed to do a borescope inspection.
  5. K1W1

    K1W1 Senior Member

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    Hi,

    I endorse this statement 100%.

    I have recently had a battle royal with CAT over sky high Copper readings in new engines where there was a 2.5% F.O.Dilution. I was of the opinion that we were due for an imminent failure of bearings only to find that the sampling procedure on-board was about as sanitary as the underside of a bulldozer in a landfill site.

    This doesn't explain why one of the engines with 5120 hrs on it is now about to undergo it's 3rd Rear Seal replacement under warranty and each previous one has leaked as bad as it's predecessor right from the get go.

    I have had to insist that there is a full run out, bearing clearance and crank inspection done this time. It is a C18 so not even sure if they can do a meaningful set of defections with such a short stiff shaft.

    CAT say they need two men for 5 days for this, all that runs through my mind is things have changed since I was on the tools.
  6. Mike Hall

    Mike Hall New Member

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    thanks very much guys. I just got the second oil sample analysis..reads the same as the first after 5 more hours of running..I am currently scratching my head.
  7. K1W1

    K1W1 Senior Member

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    5 Hrs isnt really enough to tel you much, if you sw a big change in 5 hrs you would probably have an engine failure before the 5 hrs was up.

    Is t the same Oil Charge as the last sample was taken from?
  8. Mike Hall

    Mike Hall New Member

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    Yes the same oil. The same results as to ppm. I have had several people tell me that since the original oil sample was taken from a cold engine, the contaminants should be greater as they tend to sink to the bottom. Having warm oil yield the same results is confusing.
  9. Marmot

    Marmot Senior Member

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    An oil sample should always be taken from a running engine at normal operating temperature.

    Like K1W1 suggested, if you had a change over 5 hours I wouldn't stand too close to the engine.

    All of this discussion points to the reasons why an oil sample taken on its own with no history isn't worth what it cost to get it to a lab. A brand new engine is going to have high wear metals compared to a nicely worn in engine and a worn out engine might not be making metal because the liners are polished. You really need to know how long the oil has been run, how much has been added since the last change, what the TBN, soot, dilution are and weigh all those factors against the general condition of the engine.

    Even then one that checks out great can fall apart on the next start ...
  10. K1W1

    K1W1 Senior Member

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    Hi,

    If the engine is not fuming or showing a high crankcase pressure you can either take a punt and run it some more and do a further sample after 50 hours or cough up for a borescope inspection yourself.

    Not knowing the hours on the oil or the original Oil charge details it could also be worth your while to change the Oil, keep a little bit to get analysed to give you a baseline and then sample the oil regularly.

    I do not know how much running you do so am not sure how long it would take to get 50 hrs running but you need to have a reasonable runtime to develop a trend and get any meaningful results.

    The CAT Oil Sample routine is called SOS Scheduled Oil Sampling for good reason, the testing should be done at regular intervals and in the report sheets the results are normally displayed showing the previous results so it is easy to see trends at a glance. Some Labs will also show the results in a graph format for a few key components.