Water Jacketed Risers

[tgotch]

Trying to educate myself a bit on Detroit Diesels, since I know nothing about them.

I have seen discussion about not wanting water jacketed risers on these engines (8v71TI).

Can anyone post a picture of insulated risers?

Is this a water jacketed riser?

 

[SKYCHENEY]

All I see in the picture is the collector elbow, no riser

 

[Captain Ralph]

I have seen discussion about not wanting water jacketed risers on these engines (8v71TI).

It could help if we found this discussion to ensure we are talking about the same component.

Exhaust risers (from the exhaust manifold or log before turbo) are usually not water cooled on 71-TIs because not needed with a dry turbo.
Wet risers are recommended on 71-TAs because of a wet turbo. There are other examples back and forth but these are the basic beginnings.

A riser is needed (water cooled or wrapped) to ensure the turbo outlet and its plumbing to a mixer can*, have a minimum height over operating sea (river & lake) water levels to keep any of these waters from flowing back into the engine. Further designs help keep the water and hot exhaust gases from flowing back into the engine.

*Mixer can, Dump can, exhaust shower nozzle and other terms; Is a device where the hot engine exhaust gasses are mixed with water. These now cooled gasses can exit further down hill to an exhaust system (collectors or mufflers), with the water, at a temperature that will not damage the plumbing material (rigid tubing and/or rubber hose).

 

[tgotch]

I was reading Pasco's article on yactsurvey.com.

"Most of these boats through the early 80's had upsweep, water jacketed risers. Which means that if the riser leaks, as it eventually will, the water runs into the engine."

 

[Captain Ralph]

I was reading Pasco's article on yactsurvey.com.

"Most of these boats through the early 80's had upsweep, water jacketed risers. Which means that if the riser leaks, as it eventually will, the water runs into the engine."

Well, there is the problem; Pasco..

A general, quick and poor comment on most all naturally aspirated engines, including Detroits.

IMO, lot of his reading should be questioned (as you did).

 

[whoover]

I had jacketed exhaust on my 42c built by K Industries in Detroit and the port side did finally leak. It lasted 47 years with a life spent mostly in fresh water. I bought new mixers from Tony Athens at SB Marine and had a high pressure pipe fabrication shop build me new risers with the mixers attached. Now there is no chance of water entering the engine. I would like to add that service from SB Marine was excellent.

Walt Hoover .

 

[Captain Ralph]

I had jacketed exhaust on my 42c built by K Industrie

Those were Cummins or Detroits?

 

[whoover]

Cummins 903 Ralph. No turbos.

Walt Hoover

 

[cww]

Trying to educate myself a bit on Detroit Diesels, since I know nothing about them.

I have seen discussion about not wanting water jacketed risers on these engines (8v71TI).

Can anyone post a picture of insulated risers?

Is this a water jacketed riser?
View attachment 55112

Far as I know none of the turbo 871's hatteras ordered came with wet risers, this is only an issue for the naturally aspirated ones. If you have ti's then you are immune to the problem. I have never seen ti's with wet risers. My other boat had them though (853 na's) and they weren't a problem. I had them removed and inspected when I got the boat and they were fine, and they're still fine 7 years later.

 

[Captain Ralph]

Cummins 903 Ralph. No turbos.

Walt Hoover

Was wondering if Tony even looked at a Detroit.
Yes, Seaboard marine is a great shop.