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Flappers on exhaust

T

tbrodes

Regular Contributor
"Hey guys,

My boat is a 19

"Hey guys,

My boat is a 1991 29' with twin FWC 454's. My exhuast ports do not have rubber flappers on the exhausts. The engine has plenty of rise above the water line, but I feel it would be good to install the flappers as another security against water intrusion. Who sells them, and how do you install them? My exhausts have fiber glass gelcoat all around then and are kind of molded into the boat (anyone understand cause I'm being vague)...

Any and all help appreciated!"
 
I see they attatch via a hose

I see they attatch via a hose clamp. But I do not think that would work on my exhaust ports....
 
How about bolting on an alumin

How about bolting on an aluminum angle and attaching a homemade rubber flapper to it? Did something like that on mine.

Jeff
 
yea not a bad idea jeff. I wil

yea not a bad idea jeff. I will have to look at them this weekend when I head down to the house. Would the flappers dampen the growl of the engine much?
 
"Hey Ted,
Brian from the

"Hey Ted,
Brian from the northshore here. I have a 29 Blackfin Flybridge with twin 454's FWC and rubber flappers on exhaust ports at stern of boat and still get a good growl out of them. They sound pretty good from my house! Hope that might help you a little."
 
..."Would the flappers dam

..."Would the flappers dampen the growl of the engine much?"

Yes! I was surprised at how much.

Jeff
 
"Are these flappers something

"Are these flappers something that really help this problem? I can add them to the exhaust ports on my exhaust as there is a bit of room but someone told me not to bother, any thoughts on that?"
 
"Install them. All it takes i

"Install them. All it takes is one sudden drop off plane to ram water up the exhaust pipes and into the motor!

Jeff

PS: I know you're too smart to go chopping the throttles like that (though some are not), but emergency stops do happen, and all it takes is once."
 
Jeff can you explaine this som

Jeff can you explaine this some... I have a 1980 Tiara 31 Open how would I "How about bolting on angle? attaching a homemade rubber flapper to it?"
thanks
jc}
 
"You need enough pipe sticking

"You need enough pipe sticking out to attach them. If your exhausts are flush with the transom, I believe there are flappers designed for that application as well. if not, it would be simply enough to make them: buy some 1/8 inch thick rubber sheet from mcmaster.com and attach it with sheet metal screws (and large flat washers).

Jeff"
 
In my neck of the woods Michig

In my neck of the woods Michigan (yes I'm laid off) we place a small rod accross the exhaust opening along with the rubber flap to keep the muskrats out! They have been blamed for chewing thru rubber exhaust hose and causing dock side sinkings.Brazing rod around .060 diam.works well. STILL SNOWING...
 
"My exhausts are on each side

"My exhausts are on each side of the boat and partially below the water line at rest. They also do not protrude so I can't use the clamp-on style of flappers. Inhaling water due to a sudden stop should not be a problem with them on the side. What is annoying is the water that gets splashed around while at the dock, getting water on my neighbors boat on one side and on the floating finger pier on the other. Attaching flappers to these ports would not be easy, but keeping them attached while underway would probably be even more difficult, although they may be higher above water line when on plane. Any suggestions?

Thanks,
Erich"
 
"When you really need these is

"When you really need these is adrift in heavy seas with engine(s) off. Or, any reverse action with one engine off. I don't understand the noise damping remarks. These are fully open during engine on. Are folks saying the flaps quiet the engine?"
 
"..." Are folks saying the

"..." Are folks saying the flaps quiet the engine?"

Yes, and surprisingly so. I installed them to keep the water out and was pleased to hear a noticable difference. The increase in back pressure is enough to reduce some of the exhaust roar.

Jeff"
 
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