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Diesel exhaust

Discussion in 'Technical Discussion' started by Gerdie, Nov 4, 2015.

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  1. rgsuspsa

    rgsuspsa Member

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    This post was entered in order to clearly refer to invention of the Diesel engine. Post No. 20 was insufficiently clear about this point.

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  2. K1W1

    K1W1 Senior Member

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    Surely if there is as much CO in a diesels exhaust as you would have us believe it would set off a detector even if the humans couldn't actually smell this component of the burnt hydrocarbon which is the exhaust.
  3. rgsuspsa

    rgsuspsa Member

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    KIWI: No statement as to any specific concentration of CO has been made by me. Every engine in actual service will expel CO when it is running, and the concentration will be variable as a function of numerous factors affecting a specific engine. Some of those factors include actual chemical composition of commercially available diesel fuel, diesel fuel having no specific molecular formula in practice, air temperature, engine temperature, engine load, fuel injector condition, gas leakage of engine valves, gas leakage of piston rings, fuel atomization by the injector(s), combustion chamber shape, combustion chamber deposits, and many other factors too numerous to list completely.

    Regarding whether a CO detector can detect CO in diesel exhaust, that will be a function of the sensitivity of a specific CO detector and the actual concentration of CO in the exhaust gas at any given time. What is a factual certainty is CO is always produced by a running, diesel fueled engine simply because no combustion engine of any kind ever built can completely combust, (Carbon + 2 atoms of Oxygen = CO2, which is carbon dioxide, the product of complete combustion of carbon) every carbon atom in diesel fuel, or any other hydrocarbon fuel for that matter.

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  4. K1W1

    K1W1 Senior Member

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    Go back and re read your post at No 9 then where you state it is as bad as gasoline
  5. rgsuspsa

    rgsuspsa Member

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    There was no statement in post No. 9 as to concentration level(s) of CO produced by combustion of gasoline, diesel, carbon itself, which is essentially coal, or any other fuel containing a carbon atom in its molecular structure. By definition, carbon monoxide (CO) is carbon monoxide, irrespective of the base fuel from whence it is produced.

    Your assertion that I stated, "...it is as bad as gasoline", is categorically false, I made no such statement. In fact, that phrase was written solely by you in your above post No. 24.
    Falsely attributing your statement to another person is unacceptable conduct. Persons
    worthy of credibility do not conduct themselves in such manner.

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  6. Capt J

    Capt J Senior Member

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    Carbon Monoxide is also absorbed through the skin as well as the lungs. CO can be very deadly and is admitted by anything burning any type of fossil fuel, whether it be gas, diesel, wood, coal, or anything else. Diesels do produce 28x less CO than a gasoline engine, however an accumulation of enough of it is still deadly given enough of it or long enough exposure. If a diesel engine is in poor running condition, it will also spew out more Carbon Monoxide than normal as well.
  7. Marmot

    Marmot Senior Member

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    Try this one:
    http://www.jabfm.org/content/21/1/55.full

    Post #19 "Installing an ultra sensitive CO detector in the area(s) of the strongest smell might be a good way to determine if the source of smell is an exhaust or a fuel issue."

    If there is a detectable level of CO present due to an exhaust leak the alarm will detect it. If there is no detectable CO present, the absence of an alarm condition should provide a strong clue that an exhaust leak is probably not part of the problem. No one said anything about using a CO detector to detect the presence of diesel fuel.


    Post #9 clearly states:
    Given that diesel exhaust normally contains less than 4 percent of the CO content of a gasoline engine of equal power, the danger posed by CO from the diesel engine is actually quite a bit less ... about 96 percent in fact.

    There is ample support for the fact that diesel exhaust is highly toxic and even more so than that of gasoline engines. However, this is mainly due to particulates and other chemical emissions. Carbon monoxide is a very low risk component of diesel engine exhaust, particularly in a recreational marine propulsion environment.

    If you lock 50 people into the sealed cabin of a small boat and direct the total production of diesel engine exhaust directly into the cabin for an hour or more, then yes, chances are the mortality rate will be high. This does not represent a typical recreational boating scenario.
  8. MYTraveler

    MYTraveler Member

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    It is not necessary even with Detroits, but many boats suffer from this problem, so to that extent it is normal. There is no reason that either diesel or exhaust should be present even in the engine room, let alone migrating from there to the salon or staterooms. The fuel system should be entirely enclosed (at least within the boat, vents overboard are necessary), precluding any chance of unburned diesel fumes. But, if injectors, etc., are leaking, the distinctive smell of diesel will be present in the engine room, and from there it will permeate the interior of the boat if the engine room is not well-sealed. The same applies to exhaust -- no need for a leak, although backdrafting may occur, depending on engines, and boat design and conditions.
    Plugging all of the exhaust and fuel leaks, together with a thorough cleaning of all surfaces in the engine room, should eliminate the problem. If interior surfaces have become absorbed these odors, they may persist for months/years. In that regard, judicious use of an ozonizer may help.
  9. MYTraveler

    MYTraveler Member

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    CO is odorless, carbon chains are not.
  10. K1W1

    K1W1 Senior Member

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    The highlighted words or less dangerous read to me that there is the same risk of CO poisoning by anyone who inhales a Diesel Engines exhaust as to anyone who inhales a Gas engines exhaust.
  11. Marmot

    Marmot Senior Member

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    CO emitting from the (untreated) exhaust of a diesel engine will be accompanied by the other 96 percent of the emissions which have a quite distinctive odor.

    The purpose of the CO detector is to act as an indicator that exhaust is or is not present. If there was a diesel exhaust smell detector on the market I would have suggested that instead. However since CO in this context will not exist on its own then when used as suggested the detector should provide a clue that an exhaust leak may exist. Think of the CO detector in the same way a doctor uses an antibody screen to detect or eliminate conditions that are not otherwise readily apparent.
    Last edited: Nov 8, 2015
  12. Capt J

    Capt J Senior Member

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    I think we're splitting hairs here. Diesel exhaust from a CO standpoint is much less dangerous than Gasoline engine exhaust, however all of the other hydrocarbons in diesel exhaust make it more dangerous to humans than gasoline exhaust as a whole. Either way, it's not healthy to humans to have exhaust inside the boat from any engine.
  13. Marmot

    Marmot Senior Member

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    I don't think anyone has claimed otherwise. In fact that point has been very clearly stated in several previous posts.
  14. rgsuspsa

    rgsuspsa Member

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    What an intellectually dishonest, evasive comment.

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  15. NYCAP123

    NYCAP123 Senior Member

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    Actually it's neither dishonest nor evasive. It was accurate. Take a look at post # 19 where he said:
    "The other nasty stuff in diesel exhaust has a well documented history or causing health problems and that should be the driving force behind finding and eliminating exhaust leaks."

    CO production from diesel is nowhere near what it is for gasoline. That doesn't mean Diesel exhaust is safe nor that its CO content is good for you. K1W1 and Marmot pointed out that the emphasis on CO instead of the other chemicals is misplaced. It's like saying that people die in car crashes because of children in backseats distracting the driver. True they're distracting and crashes do occur because of them, but you're ignoring texting while driving, DUI, bad tires, and the things that are actually shown to cause many more car crashes than the kiddies.
    Last edited: Nov 14, 2015
  16. Bamboo

    Bamboo Senior Member

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    IMHO the exhaust fumes are most likely not the issue since you detect the odor days after the engine was last running. Does you fuel cell vent routing come close to where the smell is strongest?
  17. Marmot

    Marmot Senior Member

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    Not to mention post #27"

    "There is ample support for the fact that diesel exhaust is highly toxic and even more so than that of gasoline engines. However, this is mainly due to particulates and other chemical emissions. Carbon monoxide is a very low risk component of diesel engine exhaust, particularly in a recreational marine propulsion environment."
  18. NYCAP123

    NYCAP123 Senior Member

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    Good for YF for editing out the insult rgsuspsa tried to throw. Unfortunately they came across on my phone uncensored. I'm not real thrilled with the caliber of YF members I've encountered here lately. I don't like their baiting nor their personal attacks on me and others, including the deceased. People like I've encountered here lately belong on Craigslist, not a Forum such as YF used to be. Therefore I'm resigning my membership.
  19. MYTraveler

    MYTraveler Member

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    Although I have never had occasion to use it on this site (as I am pretty thick skinned), and therefore cannot confirm that it even offers the capability, on least on some similar forums it is possible to "ignore" a user. It greatly improves the user experience -- you might reconsider your decision to resign your membership, especially since I don't think you are getting even a pro-rata refund.

    Update: The ignore feature is alive and well on YF.
  20. Bamboo

    Bamboo Senior Member

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    life moves on. Still looking to find out if a fuel cell vent line is close to where the smell is strong.