Wet diesel exhaust hose

I need to replace 1 wet exhaust hose (but also the other while there) on my Perkins Range 4, 200 HP engines.
They both are 3 foot in length from the riser to the muffler with a small bent into the mufflers. In looking into flexible wet exhaust hose, they seem to all have different temperature ratings, say from 200F to 600F or more. Being a turbocharged motor, although a wet hose, I would assume the higher heat rating the better?

Goldenstar38 said:

Being a turbocharged motor, although a wet hose, I would assume the higher heat rating the better?

Click to expand...

Yes

The sea water flow thru the engine into the exhaust should always be high enough that it does not go above 140F or so.

This is so the components do not clog up with salt deposits.

No need for higher heat rating. My Turbo Perkins has had the same std exhaust hose on it for 18 years. Invest the difference in a seawater flow alarm, b/c if you loose your flow either hose will be gone in moments.

Brooksie, I think this makes the most sense for my application.
Thank you.

I know nothing lasts forever, but I have to ask why you need to replace the hoses?
If they are damaged due to heat, you may well have other issues to solve, or you will just be frying the new hoses too.
If this is a fairly straight run, I would consider using fiberglass tubing connected with short couplings of rubber hose.

One hose is collapsing in the center. The PO had tried to place a hose clamp around it to open (make round). While I have been in the maintenance mode, wanted to just replace them both as they are the easiest chore I have to do. I have no idea as to how old they may be, so if replacing one, just do them both together.

Using a higher temperature rated hose doesn't always have to do for when things are working normally.

The Eagles exhaust can be wet or dry by opening or closing a through hull. However what comes out of the exhaust tail pipe is not as important as what goes thru the exhaust manafold and or engine. The Eagle had dry exhaust when we bought her, very hot and noise. So the exhaust system was changed to a hybrid design by an marine exhaust shop and myself. We did not like hated the dry exhaust, so we modified to a preferred wet muffler and water muffler, which also allow for optional dry. We have never used the dry option. Wet made the boat and engine room cool and quiet. The water muffler is mounted high so it self drains. Since we prefer wet keel cool was not considered.

As mentioned before what is more important is not having raw water cool the engine or manifold, so we have dry fresh water engine manifold and wet exhausted where exhaust and water comes out of the exhaust pipe. As on old school rule hoses belts clamps should be replaced ever 10 years.

Keel cool after being on the commercial dock and yard I would not covert to. First they are expesive to install and have to be sized correctly. There are 2 through hull holes rather than one. I had all the thru hulls filled in except the gen set and engine in takes.

OPPS post to wrong discussion should be wet vs dry exhaust. Oh well!

The exhaust system has no issues, other than a collapsing hose. I have run it for 2 years in this condition, but I want to take care of these issues now.

Goldenstar38 said:

The exhaust system has no issues, other than a collapsing hose. I have run it for 2 years in this condition, but I want to take care of these issues now.

Click to expand...

Before the water pump the hoses have to be reinforced or solid so the pump is sucking. After the pump the hoses do not have to be as the pump is pushing. Also make sure the thru hull filter are not clogged restricted.

Sorry I posted to the wrong discussion. What can I say, but I an OLD.

What you want is labeled "marine wet exhaust hose" which is an SAE designation. Just buy that; the silicon stuff is best, but $$$, not listed on this Defender page.

Marine Flex Wire Reinforced Exhaust Hose on Sale

http://www.starmarinedepot.com/trid...Z4uFHhPTpbxfdkp93Lqx_JhICGQv2BqsaEaAnpH8P8HAQ

Phil Fill, No worries. If my head were not attached to my shoulders, I know I would misplace it! BTW, the Roughwater is a beautiful boat! I remember looking at a 42 (?) years ago.

Sounds like your "small bend" into the muffler is the culprit, the outside of the bend is in tension, the inside in compression, add some heat, and it collapses.
You need a fiberglass piece made up to allow a straight shot from the elbow to the muffler.
Wire reinforced hose is better suited to bending without collapsing.
What is the orientation of the hose?
If it is horizontal, make sure that it has down angle and is adequately supported to prevent ponding, again much easier to accomplish with a rigid fiberglass tube.

Yes, do it in fiberglass. No more probs.

"Yes, do it in fiberglass. No more probs."

Be sure to specify FIRE RETARDING RESIN in any exhaust use of GRP.

I recently replaced my exhaust elbows, including the 90° bend to get the entry to the water mufflers strait. The new part was made of Fibreglass and readily available for about the same cost as the old rusted steel one.

FF said:

"Yes, do it in fiberglass. No more probs."

Be sure to specify FIRE RETARDING RESIN in any exhaust use of GRP.

Click to expand...

Be sure you have a knowledgeable glass guy either do the work or advise you. A lot of folks mix incompatible materials that appear to be firm but will soon start to delaminate. Also using a heat gun between processes makes for a more durable and harder surface.

Be sure to specify FIRE RETARDING RESIN in any exhaust use of GRP.[/QUOTE]

So are rubber hoses are immune to fire?
Most all boats have it in at least some portion of the exhaust system.
The fire retardant resin thing is incredibly overrated, just another issue that is designed to make stupid surveyors look good with a big sheet of discrepancies.
The most common cause of fiberglass exhaust tube delamination is overtightened hose clamps that expose fibers to water and exhaust gasses.

ALL GRP will burn. HOW much is the question.

The cheap stuff burns 5 times faster than oak.( The USCG burn yardstick) rating 500

F-R resin burns at the same rate as oak rating 100

A burn rating of 15 is easy to obtain if the part uses additives and is created 5% stronger than minimum.

Rated self extinguishing..J

A 15 burn rate is so cheap and easy to obtain , I have no idea why it is not a universal requirement for hulls and decks ..

kapnd said:

Be sure to specify FIRE RETARDING RESIN in any exhaust use of GRP.

Click to expand...

So are rubber hoses are immune to fire?
Most all boats have it in at least some portion of the exhaust system.
The fire retardant resin thing is incredibly overrated, just another issue that is designed to make stupid surveyors look good with a big sheet of discrepancies.
The most common cause of fiberglass exhaust tube delamination is overtightened hose clamps that expose fibers to water and exhaust gasses.[/QUOTE]

So I take it you will personally insure the OP if he takes your advice?