A Little Advice Please

Hello guys hope you can help me again. Last yera my 3.0L Cobra had a good old drink on a large quantity of salt water.The whole engine ground to a halt and cost me a packet to put right. Anyway I had the engine re done and took the advice to change the manifiold and the elbow as the originals were in poor condition. The diagnosis at the time was something to do with a 'flap' that had malfunctioned allowing salt water to ingress the engine, though the engineer said that if the manifold was not changed the sooner or later the situation would re occur (hence my changing). Does anyone know what was meant by the flap, as this season I am a bit wiser and intend to do the maintenance myself.

Re: A Little Advice Please

I am not the best person to reply, I am sure there will be others shortly. I think your mechanic is talking about your exhaust flappers. Which will/can go bad....not to sure how you do the maintenance on them though. I know this didn't help much, but hopefully some.

Re: A Little Advice Please

I think you are on the right track.Apparently the water got into the engine via this/these 'flap (s)' ( not sure how many there are).I could do with finding out about maintaining them.Cannot afford a new engine every year thats for sure! Thanks anyway though.

Re: A Little Advice Please

That is not the USUAL way for water to get in like that. The most common reason is the riser, manifold or the gasket between them fails. The flappers prevent a large flow of water into the engine, but they can not and were not designed to be water tight. So if you are shutting your engine off at high speed and allowing your wake to hit the boat, the flapper (aka exhust shutter) even a new one may not stop the water coming in.

Re: A Little Advice Please

Thanks for the advice. Just exactly were will I find the flap, and is it easily accessible .

Re: A Little Advice Please

Howdy,

In the picture below from Doug Russell

#81 is the "flap" also known as an "Exhaust Seal"


This may not be the correct year for your application. You didn't indicate the year so I just picked a typical one...you'll have to select the right model and year for your application. Then you can buy directly from them or other companies that advertise on the web



It's simply a check valve that helps to prevent water from sloshing up into the elbow and over into the manifold (and then subsequently into an open exhaust valve)

Like Don said. It probably WILL NOT prevent water from coming up into the elbow if you shut the engine off while underway.

Cheers,

Rick

Re: A Little Advice Please

Thats great.The diagram does apply to my set up.Mine is a 1989 engine. I have relaced the manifold but I am not a lot wiser as to the perils of closing down the engine too quickly whilst at sea..Thanks again.
Bill.

Re: A Little Advice Please

Not to mention the fact that Volvo put out a bulletin not to replace them as their benefit was negligible compared to the problems they caused. At least on the SX series. Don could clarify further if they are not in any of the newer lines

Water ingestion through the exhaust is more of an operational error than a mechanical one. Slow down and idle for a bit before you shut down and flapper or no flapper you'll be fine.

I agree that risers/manifolds are the usual suspects

M