exhaust fumes on fly and aft cockpit

[ianainge]

Can anyone confirm they have the same problem and how to remedy it or is it a charactaristic. When i accelerate up to about 20 knots the exhaust smell is very apparent on the flybridge and aft cockpit as if the motion of the boat forward is causing a vacuum and the exhaust is being pulled back into the cockpit and up the ladder to flybridge.

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[jfm]

It's not a characteristic of boats generally, but might be of a specific model. Our Phantom 42 used to get soot on the tender and transom after a few hundred miles, kind of estate car effect, even if the engines were well tuned and running as clean as they could. Current boat doesn't do it at all.

But we could never smell diesel on the flybridge even on the phantom, so maybe you do have a problem. It could be engine tuning (fixable) or boat aerodynamics (not fixable much). There's also Soltron.....


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[miket]

No.........!!!

Don't mention the dreaded S word!!

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[DepSol]

Re: No.........!!!

Why not? /forums/images/icons/smile.gif

<hr width=100% size=1>Dom

<A target="_blank" HREF=http://www.soltron.co.uk>the website</A>

 

[tcm]

hi ian.

tis most certainly a known prob for tall-profile boats to have the back-eddies which land exhaust on the transom. On any boat, the ciggie test will show a solid flow of air from the stern towards the bow, and hence lots of boats with white carpets need their carpet cleaning cos they go grey unless the patio doors are kept shut.

But even with this backflow, it should not be a right old stink.

Soltron is a spanner-free option to try, although i think it should be done in conjunction with a damn good thrashing - ie a long long run. Oil change (or even an oil flush and then a change) together with new filters. If this doesn't work in getting rid of the dieselly smell, you may need injectors looking at as you are smelling unburnt/part burnt fuel.

Aerodynamically i am not at all sure there is much that can be done, but it might be worth a try here and there. The name of the game is to try and leave the airflow to run behind you smoothly, rather than trudnle bricklike through the air. Carwise, they do this with quite small adjustments - noticeably on frexample an Allegro estate with that little upward turn at the back of the roof, for example. If you can sharpen and lengthen the trailing edges of the boat and put the exahust into that airflow it will leave you. I used to be invloved in modelling airflows (dead boring aftyer a few weeks!) and tiny changes to baffles/forms utterly change the airflow. Tape a piece of flat cardboard horizontally on top of the rear transom frexample would separate that area from the exhaust but not increase drag. Same for the radar arch - deeper (fore and aft) radar arches with tapered edges will leave the air less disturbed and hence less backflow.

t'other way around is to move the exhaust fumes away from the backflowing air in your wake. Anything to turn them to the side, or further behind will help. A simple baffle (sticky-out bits of plastic or rubbber just a few inches ) on the stern at either side would make the exahust less able to join the backflow. More expensively, the exhaust specialists will certinaly be able to help with more serious gear to dump the exhaust underwater or out to the side, or both. But i wd try with lashed up bits of plastic first - and of course try and make it so that teh exhauist doesn't pong like mad anyway.

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[Nick2]

Ian

Are you actually getting a deposit of soot or just the smell?

Nick

<hr width=100% size=1><A target="_blank" HREF=http://arweb.co.uk/argallery/Nick2>http://arweb.co.uk/argallery/Nick2</A>

 

[Col]

Wondered how long you would take to chip in /forums/images/icons/laugh.gif

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[ianainge]

no soot just smell, once up and running no smell at all, only really on excelleration, exhaust outlets are on the side already.

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[jfm]

In which case ian it sounds like an engine tune-up rather than an aerodynamic re-work is needed.

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[hlb]

Re: Smoke. Did Some One Say Smoke!!!

<hr width=100% size=1> <font color=blue>Specializing in marine sanitation since 1997.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[Freebee]

Re: Smoke. Did Some One Say Smoke!!!

so thats why you call it mucky farter!!

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[solent_hazard]

Re: Smoke. Did Some One Say Smoke!!!

Thats what my 35 looks like each morning - tried injectors (650 quid) etc etc - told that next thing is to adjust the timing - anyone know how to do that on the green 200's ?

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[hlb]

Re: Smoke. Did Some One Say Smoke!!!

That was taken on one of it's better days. On a bad one there would be no picture at all!!

<hr width=100% size=1> <font color=blue>If you thought my boat was dirty. You want to meet my girl friend!!
Haydn

 

[Col]

Re: Smoke. Did Some One Say Smoke!!!

That's actually just the Eberspacher, the engines are much worse....

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[hlb]

Re: Smoke. Did Some One Say Smoke!!!

Ok. So I told you the tale of the Eberwatsit starting up at the fuel barge in Falmouth. But I never told the attendant to jump ship!!.../forums/images/icons/laugh.gif

<hr width=100% size=1> <font color=blue>If you thought my boat was dirty. You want to meet my girl friend!!
Haydn

 

[deborahann]

Re: Smoke. Did Some One Say Smoke!!!

oh yes does "mucky farter smoke" yes, yes, yes, all boats smoke. but to varying degree's. just be glad its not at MF level i.e. don't compain, unless you cause, by firing your engines up, complete marina blackout (the previous photo could only be taken, well actually seen, after some of the huge amount of smoke had cleared ) have been on a few boats when others around have been ready to call the fire brigade, but "its really only my ebberspacher firing up" - honest.

think boat are designed to embarass you really.

<hr width=100% size=1>deborah on delft (correct spelling)

 

[Talon]

Re: Smoke. Did Some One Say Smoke!!!

Wow, that is what ours looks like when we start the engines!

We all ended up down the jetty putting on our life jackets as we could not breath near the boat.

We have Volvo 31's, the engineer stood there in the smoke saying that "this is not that bad for these engines!!" We were amazed as it was exactly like the above picture.

By the time we get going it seems to be better, however when we reach our destination the back of the boat is black and need cleaning off, which is bloody hard work let me tell you.

So we did an experiment this weekend and removed all the cockpit covers so that back of the boat was open. Amazingly, only the swim deck got black on it, so the covers being on definitely cause suction behind the boat.

We are in the process of trying out this soltron additive, no results as yet, I will post up if it makes any difference.

<hr width=100% size=1>Alex

<A target="_blank" HREF=http://www.mad-als.com>http://www.mad-als.com</A>

 

[Wiggo]

Re: Smoke. Did Some One Say Smoke!!!

specialist job, I'm afraid, AFAIK. In tehory, it's just a case of loosening the clamp bolt on te injector pump body, and twisting it till it's set right, but how you tell what is 'right' is anyone's guess...

<hr width=100% size=1><A target="_blank" HREF=http://homepage.ntlworld.com/graham.wignall/boats/eulimene600x800.jpg>The old and the new</A>

 

[adarcy]

Ian

Do you shut the flybridge stair cover?

As has been said it is the backflow that is at least part of the prob. If you can keep some air flowing aft through the cockpit your problem will lessen. We don't need to keep the saloon door and side windows ajar, the opening over the steps does enough