Cat 3208 Natural exhaust risers

Who is your source for replacement exhaust risers for Cat 3208. They're old and will soon be pulled for inspection. I want to know where to get them and lead time.

I will be contacting Greenwater Marine Exhaust and my local Cat dealer. Looking for other sources.

And a question. Greenwater offers dry risers with insulation. How / where does the water enter to keep from burning up the exhaust system?

Thank you.

Just by coincidence, the boat I'm buying has a single 3208na with dry risers. The exhaust is stainless and insulated as it leaves the engine. The two exhausts combine into one with a single riser at the point where it exits the engine room. After that the insulation stops and normal rubber exhaust hose continues to the transom. Works great!

Years ago we had our 3208na exhaust on our GB50 made by National Marine Exhaust in Marysville, WA. They are still there. We were very happy with their work.

Later, Tator

heysteve said:

Just by coincidence, the boat I'm buying has a single 3208na with dry risers. The exhaust is stainless and insulated as it leaves the engine. The two exhausts combine into one with a single riser at the point where it exits the engine room. After that the insulation stops and normal rubber exhaust hose continues to the transom. Works great!

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Where / how does the water enter? Without cooling the rubber and fiberglass parts of the exhhaust will burn up.

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Tator said:

Years ago we had our 3208na exhaust on our GB50 made by National Marine Exhaust in Marysville, WA. They are still there. We were very happy with their work.



Later, Tator

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Thank you. I'll reach out to them.

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Portage_Bay said:

Where / how does the water enter? Without cooling the rubber and fiberglass parts of the exhhaust will burn up.

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The riser is just like the one that would have been on your engine only it's in a remote location. It takes hot exhaust in one side, adds the raw water exiting the engine and cools it so a rubber exhaust hose can handle it. The engine raw water hose is routed to the remote riser. By "remote" I simply mean it's about 5 feet from the engine instead of mounted to the engine. Does that help?

I also have dry risers (stainless and insulated). Each riser has a raw water entrance (split from the raw water cooling system exit) followed by a rubber hose to a stainless Y that combines them before the lift muffler.

Portage_Bay said:

Who is your source for replacement exhaust risers for Cat 3208. They're old and will soon be pulled for inspection. I want to know where to get them and lead time.

I will be contacting Greenwater Marine Exhaust and my local Cat dealer. Looking for other sources.

And a question. Greenwater offers dry risers with insulation. How / where does the water enter to keep from burning up the exhaust system?

Thank you.

Click to expand...

Your Cat parts store will have them. The part numbers are 8L3453 and 8L3454 per engine. I replaced mine about four years ago. Don’t forget to order the spray rings that go with them.

The cast iron parts are getting hard to find. I was quoted $6000 for 4 risers in 2019. I replaced the wet risers on our 3208NAs with custom stainless steel dry risers a few years ago (Greenwater Marine). Direct replacements. Half the price and no danger of sea water leaking into the engine.

It's looking like custom stainless is the way I'll have to go. The usual trustworthy Cat dealers can't find the cast risers. I have little interest in paying $6000 for cast risers even if the dealer can locate them when there are other options available.

gsholz thanks for the pic showing how / where the cooling water gets into the exhaust when using dry stainless risers.

Give Greenwater Marine Exhaust a call. I was very pleased with their product/delivery/etc. Just a happy customer, no other connection.

I finally heard back from my Cat dealer. Cat now wants $2252 each for the cast risers that include the spray rings. No, that's not a typo, making it $9,008 for all four. I'll be calling fabricators for quotes. Greenwater Marine Exhaust in Texas, National Marine Exhaust in Washington and Marine Exhaust Systems in Alabama. The last recommended by my dealer. If they are all about the same $$$ and lead time I'll probably go with National Marine Exhaust because they're in my hood. I can see their shop, talk face to face and resolve any minor issues easily.

Thanks to all who posted here for your suggestions on vendors and pics of your installations.

This is all proactive sourcing and pricing for work I anticipate doing this winter. I let the zincs in the risers go too long.

This is a steep climb up the learning curve. I come from the world of dry stack keel cooled boats where this sort of thing was never an issue.

I fitted the Greenwater exhaust elbows two years ago after advice from this forum, and very happy with the quality, fitment, advice from manufacturer/owner and the fact raw water can’t get back to the cylinders, unlike a failing OEM version.
Even after our poor dollar exchange rate, freight and horrendous multiple government import tax’s, the Greenwater product was a big cost saving over the poorly designed Cat OEM option.

The pics show the raw water plumbing system I chose to keep any potential leaks away from the top of the engines, and low into the bilge. The exposed small diameter hose barb at the bottom of the plumbing fittings, connects to the red plugged hose supplying raw water to the prop shaft stuffing box.

Southern, Thank you for the pics. Makes it easy to understand.

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The raw water plumbing system that best suits your own arrangement will be the biggest decision to make.
I copied the SS T fittings idea from gsholz originally and adapted it to suit my own exhaust arrangement.