Exhaust hose dropping down below muffler

lipets · Aug 8, 2019

The PO replaced the exhaust elbow, the yard also installed a new hose from the elbow to muffler.

the first pic is the port engine which looks good as far as the hose (no so much the rust??? on the elbow)

It looks like I should shorten it to be a bit more level?

Also the new elbow appears to be turned away from the direction of the muffler, can those elbows be turned easy enough?

SoWhat · Aug 8, 2019

It all looks cosmetic to me. As long as the hoses are sloped down you're good. You might try loosening all the clamps and see if you can twist the hose up onto the elbow a little more.

Take a wire brush and some emery cloth to the rust. Spray it with high temp rustoleum.
The elbows are thick and won't rust through anytime soon.

kchace · Aug 9, 2019

If its minor, its probably not the end of the world, but if that's actually a low spot in the middle, I would try and get that out. Perhaps just shortening the hose a little will be sufficient or maybe a support would help. Not sure you can turn the elbow.

Ken

DavidM · Aug 9, 2019

Hard to tell from the pictures, but it looks like your exhaust elbow is not self draining, ie it retains a slug of water in it after shutdown that could rust out and drain back into the turbo. See the attached pic for an example. You can see the water level sitting inside. Tony Athens calls these elbows "doomed to fail".

Two solutions:

1. Replace the elbow every five years or so to prevent rusting out.

2. Redesign the exhaust system so the elbow is self draining.

David

ben2go · Aug 9, 2019

lipets said:
The PO replaced the exhaust elbow, the yard also installed a new hose from the elbow to muffler.

the first pic is the port engine which looks good as far as the hose (no so much the rust??? on the elbow)

It looks like I should shorten it to be a bit more level?

Also the new elbow appears to be turned away from the direction of the muffler, can those elbows be turned easy enough?

Have a read through this and check out Tony's tip section.

https://www.sbmar.com/featured-article/everything-you-need-to-know-about-marine-exhaust-systems/

https://www.sbmar.com/tonys-tips/

rclarke246 · Aug 9, 2019

As the guy that had to replace his turbos and then risers with less than 100 hours, take it from me, get the belly out of that exhaust hose!

Details can be found on:

http://www.trawlerforum.com/forums/s60/beneteau-st-44-potential-sea-water-intrusion-35913.html

and boatdiesel.com

lipets · Aug 9, 2019

Sbar is great source, please be mindful Benne didn't do this hose it was the PO who IMO just let the yard do the work never double checking it was done correctly.

That's pretty much why I do all my own work, unless it outside my limits being too heavy (like props & cutlass)

I looked today at the waterline and the elbow is way above it about 18"

David I'll get better pics.

but here's bad sketch for now elbow on left./muffler on right
the drop down is about 10"

AusCan · Aug 9, 2019

The hose should be sloping down to the outlet to ensure good drainage, and so water doesn't flow in if you have waves lapping against the transom.

Don't shorten it. Install a hanging support midway along the hose to lift the hose 20" in the centre.

lipets · Aug 10, 2019

djmarchand said:
Hard to tell from the pictures, but it looks like your exhaust elbow is not self draining,

David, ran the engine a bit, pulled the elbow hose it was dry inside elbow, all was self draining so that looks good.

I assume if I loosen the clamps I can rotate the elbow but maintain the height.

Get it aligned better and shorten that hose to straighten it out.

Ski in NC · Aug 10, 2019

Mixer could be rotated more downward and excess hose trimmed. That would likely allow mixer to drain. Worst case put a 45 or 90deg elbow to get a cleaner run.

No harm having a low spot in the hose, but it is kinda sloppy work. Not needed. plenty of room to do a clean run.

lipets · Aug 10, 2019

Sloppy is an understatement,

the PO paid a yard about $1800

for that work two years ago, if I didn't see the old bill I wouldn't believe it.

Exhaust hose dropping down below muffler

lipets

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SoWhat

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kchace

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DavidM

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ben2go

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rclarke246

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lipets

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lipets

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Ski in NC

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