Neglected Risers

Mahalo Moi has two Cat 3208 naturals. My engine temperatures have always been spot on. Both engines run between 175 and 185 degrees F.

A few months ago, one of my port engine risers developed a pin-hole leak; spitting raw water all over the engine room. The riser had corroded through after 30 years. I replaced those port-side risers and purchased a set of risers for the starboard side. I figured if the port side has blown through the starboard isn't far behind.

I replaced the starboard-side risers last Friday and captured a few images of their condition after 30 years. The flow of cooling water out the back of the boat has seemingly doubled! Don't neglect your cooling system.

My only regret is that I didn't take measurements of water temperature and flow before and after the riser replacement. I don't have quantitative numbers to share on the forum. But what a difference in visual flow!

Thanks go to FlyWright for his manual labor!

Greetings,
Mr. G. Holy restrictions Batman! Thanks for the heads up. Yet another thing to check...So, are we to expect a new series of pictures in 2047?

You guys are hilarious!

Consider yourself very lucky the leak was external and not into the exhaust costing you an engine. BTDT on a delivery run!

Archie,


Never thought of that. Good point.

Cat exhaust risers

Just a "Heads Up"-New risers from CAT do not come with the required stainless steel spray rings. Did you order or install the spray rings?

Timcat said:

Just a "Heads Up"-New risers from CAT do not come with the required stainless steel spray rings. Did you order or install the spray rings?

Click to expand...

No. Tell me about them, Please.

What, if any, preventative maintenance can be done to eek out a longer lifespan?

Greetings,
Mr. MS. Testosterone supplements? (post #3)

Ha!

Max Simmons,

The only maintenance item I can think of is to make sure our engines are galvanically protected and the zincs are changed regularly. The elbows on my 3208 have a zinc in the bottom of each lower 90.

CAT 3208 Ex. Risers

Mr. Ray,

If you look closely at your old risers you will notice a Stainless Steel spray ring in the outlet or hose connection area. The ring is pressed onto the neck of the riser. There is also a locating pin about 2" long that goes down into the riser jacket. The spray ring is required, as it is designed to spray water into the hot exhaust gases, thus cooling gases to prevent the exhaust hoses from excessive temperatures (1,000 f) Or, your "NEW" ? exhaust hoses will prematuraly fail if the spray rings are omitted. Best to order four new spray rings from Cat, as it is extremely difficult to remove rings from the old risers. Cheers!

Max Simmons said:

What, if any, preventative maintenance can be done to eek out a longer lifespan?

Click to expand...

At 30 years old, cast iron manifolds and risers in a salt water environment, you're way ahead of the game that they've lasted that long. I wonder when Cat says they should be changed.

Yikes! No wonder you haven't been boating much in months. First the leaking fuel tanks, and now this. Hope everything gets in order for the upcoming boat season. (Current conditions have been unfavorable for boating (high winds, heavy rains, and much flotsom), unusual for your and my location.

Timcat said:

Mr. Ray,

If you look closely at your old risers you will notice a Stainless Steel spray ring in the outlet or hose connection area. The ring is pressed onto the neck of the riser.

Click to expand...

There was an assembly with what looked like a set of stators and a ring mounted into the top end of the riser. Is that what you're describing?

A picture would really help. Got a picture?

Timcat,

I have found a photo showing the hose end of the elbow. That end only shows "slots". Is this where the stainless spray ring goes? Is there a Cat part number that you're aware of? Can the rings be installed with the risers in place or must they be removed and taken to a shop?

3208 Ex. Riser

CAT part # is 8L3498 plate assem. Yes, depending on access they can be installed in place. Usually assem. with never seize.

I just ordered the part (x4) from my local Cat store. Thanks for the "heads up"! You're the man!

After roughly year 3, you will need to start annual inspection and clean out of plugged holes in the shower head.

When my risers came out, I could push a screwdriver through the back side of the exhaust outlet. There was enough drop from the manifolds that the engine miraculously stayed dry.

I installed the spray rings which were brought to my attention by our very own Timcat! Thanks, Timcat...I owe you a cold one!