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MTU/Cat Monitors

Discussion in 'Electronics' started by NEO56, Sep 17, 2014.

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  1. NEO56

    NEO56 Member

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    Does MTU/Cat have CHT's on their monitors? I've never scrolled through their Menu's. If the answer is negative, is there a system available in the after market that will provide that information to the helm station?
  2. Capt J

    Capt J Senior Member

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    What are CHT's?
  3. HTMO9

    HTMO9 Senior Member

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    Maybe Cylinder Head Temperature. A very important item to be checked and monitored on air cooled (aero) engines. On liquid cooled engines normally exchanged by monitoring the coolant temperature.

    The CHT is also monitored on the big 2-stroke diesel engines individually for each cylinder, as this temperature measurement point indicates a comming up problem earlier and faster than just monitoring the coolant temperature. Many more features are checked on the exhaust side of the engines for the exhaust gas aft treatment and the energy recovery parts of the exhaust, like EGT, TIT/ITT, just name it.

    As I said before, on modern cargo vessels, the exhaust side of the engine is almost bigger and more complicated than the engine itself.
  4. K1W1

    K1W1 Senior Member

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    Both have the ability to report Exhaust Gas Temp at each cylinder port or head in their software ..........as long as the engine itself has the facility to install an EGT Thermocouple in each location.
  5. Marmot

    Marmot Senior Member

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    Which for reasons I have never been able to comprehend, are not normally fitted.

    EGT is probably the best indicator of load (second only to a torque or power meter) and combustion condition available but seems to be one that is never requested by the engine purchaser or made standard by the engine builder, at least on the size engines fitted to even very large yachts.

    When you get used to having individual bearing temperatures and full on indicator readings for each cylinder available in real time plus trending it seems like using candles for lighting when operating a yacht engine.

    Forgot to mention, HTM09 is correct, the coolant temperature leaving each cylinder is monitored. Since the temperature at any given spot on the cover (head) might vary, using the coolant as an indicator of cylinder temperature is generally more useful for operating purposes. The common pipe that collects the coolant from all cylinder jackets is monitored separately.
  6. K1W1

    K1W1 Senior Member

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    CAT can't even tell me the Lube Temp on a C 18 without a 3rd party sender unit.
  7. Marmot

    Marmot Senior Member

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    Won't is the working word ... I don't understand that.
  8. K1W1

    K1W1 Senior Member

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    I have had some very heated arguments with the Dealer I have to deal with and have caught them lying a couple of times.

    They will tell you something you ask about is impossible then try to back pedal when you show it to them in one of the manuals they have supplied.

    The ET Monitoring straight out of the box for the C18 is minimalist at best
  9. NEO56

    NEO56 Member

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    Yes, CHT=Cylinder Head Temperture. I would think that would be something every Captain would want to know. EGT's are also important, but it's after the fact. I would want to know CHT's without having to go into the ER with a heat gun. So what I'm hearing is that CHT's aren't supported by the manufacturer. I guess I'm going to have to contact an Aircraft instrument builder, and get a custom made unit.
  10. K1W1

    K1W1 Senior Member

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    Hi,

    I would say that EGT Display and an understanding of what they mean would be every bit as good and beneficial as spending a large sum on something that can only tell you what the mass of the cylinder head is doing.

    What engines are you going to use?
  11. Marmot

    Marmot Senior Member

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    Unless you have individual cylinders ala a Gardner, a CHT readout is not going to do much good at all. Even in the case of a Gardner, by the time the coolant temperature reaches some useful differential with the others you have probably lost that cylinder anyway.

    CHT works very well on air cooled engines because the mass of the head is small, the temperature change is rapid, and there is thermal separation between cylinders. You are wasting time and money trying to use CHT to obtain useful information on a water cooled diesel.

    That is the job of EGT instrumentation. Even with EGT, unless you record trends you are only getting a snapshot. You need individual cylinder EGT with trend monitoring of that and other parameters to really develop information from raw data.
  12. NEO56

    NEO56 Member

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    I don't know yet...with all my talk about a new build, I'm putting that project on the back burner. I can't find exactly what I'm looking for in the secondary market, although a 98 ft. Ocean Alexander named jelly bean ll came really close, I'm going log some time (for insurance purposes) on a Viking enclosed bridge. While I fully intend on building what I want, I don't want to spend the next three years, maybe four on a new build. Living here in Houston provides great offshore fishing. Oil rigs make for great artificial reefs! Anyway, since the 92 is now in production, there's a bunch of 74's on the market that appeal to me. However, I've seen a couple of '06 and '07 models, one of which has 469 original hours. I'm scared of that one, she's been a dock queen, and that spells trouble...yes?

    But to finally answer your question K1W1, all of them have MTU's or Cats. On the MTU's they are M91's and M93's. Which is the better powerplant? I meant to put this on a new thread...but here is fine (Right Carl?) Anyway, being a non mechanical individual, I think I'd be more comfortable knowing CHT on each cylinder. I'm inclined to go with the 12 cylinder MTU's vs. the 16's just for lower fuel consumption. I'm going to visit the boats with the Cat's first. They are cheaper to maintain, and I don't need to run 38 knots in a boat that big. I'm actually putting my decision into your hands when it comes to power in the secondary market.
  13. NEO56

    NEO56 Member

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    Marmot, isn't there a third party software program that will track EGT on an ongoing basis? I'd like to have visual database of that information.
  14. Marmot

    Marmot Senior Member

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    You have to have the EGT reading before it can be tracked ... the elephant in this room is that few yacht size engines provide a place to install a temperature sensor.

    An EGT measured before the turbo gives an overall reading but does not tell you anything about individual cylinder operation which is what I thought you wanted because you asked about CHT monitoring.

    What are you looking for anyway, and why?
  15. NEO56

    NEO56 Member

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    Marmot, I don't have a "trained" ear like you guys have. I can tell when engines are out of sync, but that's about the extent of my talents. I'd like to have as much information at my fingertips as possible so that I could possibly see trouble before it comes a Holy Cr*p situation. Your assessment of not needing CHT sensors are understood. One less thing I'll have to pony up for. I don't relish the idea of burning the kind of fuel that big sportfishman's like Viking do. I can tell you this much...MAYBE on the way back in, I'll spool up the turbos just to keep them happy for a few minutes...otherwise she'll be run at displacement speeds. 3,000 gallons of go juice don't last very long in these boats.
    I would be interested in knowing about 3rd party solutions to finding any information on individual cylinder operations.
  16. K1W1

    K1W1 Senior Member

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    Hi,

    Choose an engine that can have EGT Thermocouples fitted and use this information as a part of over all supervision.

    If you want the full cover look first to the engine manufacturers offering, then add things you need.

    If you want to have a good cover in addition to EGT you could look at Ambient Air Temp, Air Temp After Turbo, Boost press before the charge air cooler, boost after the charge air cooler, air inlet restriction, coolant temp into the charge air cooler, coolant temp out of the charge air cooler, raw water temp, raw water press and or flow this last one is very important if you have water cooled exhausts and rubber bellows, oil press, oil temp, and the list goes on.
  17. Marmot

    Marmot Senior Member

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    It sounds like you would be better off spending your money on fuel.

    A sportsfish doesn't run far enough long enough to generate the kind of data that would do you much good even if you did understand the relationships of what you are looking at.

    Most turbos come with an outlet elbow that will allow you to fit an EGT thermocouple to show the turbine outlet temperature which is good enough for a small engine on a small boat that doesn't run at constant power for days at a time.

    If you are a data freak, the sky is the limit. Instrumentation suppliers are happy to provide every kind of sensor you can imagine along with the dataloggers and software to analyze it.
  18. NEO56

    NEO56 Member

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    No Marmot, I'm not a data freak...and even if I was, I doubt that I have the background or the knowledge base to be able to interpret that kind of data. I probably wouldn't even understand what I was looking at. Is that correct? Awhile back Simrad had a 3-D bottom plotter, that when you installed it, the hard drive (for lack of a better word) was blank. Let's say you always fished in a 200 sq. mile area, every time you went over the same area it would paint a better, more precise contour of the bottom till you had hyper accurate bottom contours, reefs, drop offs, wrecks, etc. Isn't there something akin to that concerning engine performance parameters?
  19. Capt J

    Capt J Senior Member

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    No. Who would even look at the data over and over again. EGT temperature gauges at the helm are more than enough monitoring in this situation. If you scan them like every other gauge at the helm it's enough info IMO. EGT gauges are very good for a couple of situations, such as if you decide to tow a larger tender, or if you do have that 1200lb Marlin baking in the sun on the aft deck.....or some unusual situation where you're putting a lot more weight on the boat, such as carrying fuel drums in the cockpit......

    But to monitor the temperatures of each individual cylinder or even record EGT on a 4 stroke diesel in a yacht is a waste of time IMO.
  20. PacBlue

    PacBlue Senior Member

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    If you purchase "Classed" engines, they will usually come with individual EGT monitoring. Commercial and Naval users, and others who operate their vessels or fleet of vessels professionally would not consider anything else.

    It comes down to more of a sense of ownership's perspective, extending TBO's or developing condition based maintenance programs
    Last edited: Sep 17, 2014