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-   -   Exhaust waterline question? (http://www.sailnet.com/forums/general-discussion-sailing-related/93824-exhaust-waterline-question.html)

ltgoshen 11-05-2012 04:04 PM

Exhaust waterline question?
 
So when I am under way using the 2GM Yanmar on my 1980 C&C MK1 at 2300 rpm's the exhaust port starts to go below the water line? Is this normal? I would think it would be better on top of the water line? Instead of under it..
Any thoughts on this?


I was also wandering if anybody had a like boat and engine that can give me a "SWAG" of the fuel burn? This boat seams to go for ever without burning much fuel. I have been 15 or 16 times out this summer on day sails, with little or no wind sometime and the tank has barely moved. I was Just wandering. I donít need a hard answer to many variablesí involved for truth. Something close would be close.
Thanks again.
Curtis

SchockT 11-05-2012 04:31 PM

Re: Exhaust waterline question?
 
Some boats, mine included, partially submerge their exhaust port under full power. It is not an issue as long as the exhaust hose has an adequate riser, which it should. On your boat it may be that you are carrying too much weight aft causing her to "squat" under power. I seem to recall a lot of C&Cs have their exhaust ports at the very bottom of their transom.

As for fuel consumption, you can expect to burn somewhere in the neighborhood of 1/2 gal per hour. If you have been motoring as much as you say and your fuel gauge hasn't moved, you might want to confirm that it is working. I don't have the luxury of a gauge so I use a dipstick which leaves no doubt as to how much fuel is onboard!

rugosa 11-05-2012 04:35 PM

Re: Exhaust waterline question?
 
We have the same engine in C & C, power out from winter layup to sail about 9 miles to home port, power half way to race start weekly, power out of channel to do a couple of Sunday races too, same for pleasure sails weekly and then back to layup in October. We topped up $40 diesel in September and another $10 before lift out. We pay $1.43/litre. They sip the fuel, rather than guzzling it.

We also submerge the exhaust when crew of 5-7 is in the cockpit, but the exhaust runs high to the underside of the deck by the transom so we are not concerned. Changed that 25 year old hose and fuel lines this year, sleeping better at night now.

chef2sail 11-05-2012 04:41 PM

Re: Exhaust waterline question?
 
OUr 35 MKIII C&C usually runs with the exhaust under water. It does have a water muffler and riser. Our 3GMF Yanmar uses approximently 1/2 gallon per hour at 2700 rpm. Make sure you run your Yanmar at minimum suggested rom...usualkly 3500-2700 to prevent carbong buildup in exhaust elbow.

Dave

msmith10 11-05-2012 06:03 PM

Re: Exhaust waterline question?
 
Normal for exhaust exit to go a couple of inches underwater in the C&C 30-1. The boat "squats" under power. Doesn't hurt anything. As stated above, just make sure you have a loop in the exhaust hose between the waterlift and the exhaust exit. In my boat the exhaust hose loops up high into the transom before going down to the exit point.

ltgoshen 11-05-2012 10:13 PM

Re: Exhaust waterline question?
 
There is a water muffler and going out of it there is a long hose, newer looking that goes high between the cockpit floor and the transom. So it sounds like it would be plumed correctly and I should not worry if it is gurgling. I did only notice it when we had 5 or 6 in the cockpit and pushing it a bit.
Thanks for the insight,

On the other question RPM's, how would I find out what the Minimum recommendation is for the 2GM 13 hp engine? Would you recommend running it at the top side of that setting to help clean carbon out? Like my Dad use to say he was doing with his old dodge dart?
Thanks again for the help
:o
[IMG]http://i148.photobucket.com/albums/s...t/DSCN2435.jpg[/IMG]

ltgoshen 11-05-2012 10:13 PM

Re: Exhaust waterline question?
 
Quote:

Originally Posted by msmith10 (Post 943513)
Normal for exhaust exit to go a couple of inches underwater in the C&C 30-1. The boat "squats" under power. Doesn't hurt anything. As stated above, just make sure you have a loop in the exhaust hose between the waterlift and the exhaust exit. In my boat the exhaust hose loops up high into the transom before going down to the exit point.

Thanks Mark.

msmith10 11-05-2012 11:17 PM

Re: Exhaust waterline question?
 
From the picture you posted that's a very nice looking C&C 30. I wish mine was that shiny.

chef2sail 11-06-2012 02:22 AM

Re: Exhaust waterline question?
 
lt....my exhaust is actually undermeath the transome facing down at the water below the boot strip. Oour ransome is a bit smaller and lifted out of the water though.

Dave

ltgoshen 11-06-2012 07:02 AM

Re: Exhaust waterline question?
 
Quote:

Originally Posted by msmith10 (Post 943671)
From the picture you posted that's a very nice looking C&C 30. I wish mine was that shiny.

Thanks Mark,
That photo was after her bottom job and buffing job back in march of this year, She is a fine looking boat. She sails real nice when you get her in her grove I can almost, just let her go. if she gets too much air she will try to go to weather. Ease her main ever so slightly and she's back in the grove. I didnít quite know what I was getting in for when I got this boat but, Iím beginning to fall in love all over again!!!!
I dont if you sean how bad she was when I found her. tak a look and you can tell she is looking better than she was.
S/V East Coast Lady: Photos of the progress


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