Turbo Riser Blowby

[Kevin Carlson]

I am replacing my risers and upon removing them I found significant blowby on the starboard turbo to riser interface.
I have included a picture of the starboard turbo surface and a picture of the port and starboard ‘turbo side’ gaskets.
I would like to know what caused the leakage. Do I need to pull the turbo and have it machined? Any input would be appreciated.

Topic

[firehoser75]

Exhaust Elbow Problem?

Hi Kevin,
I would strongly suggest that you remove your exhaust elbow(s) as it is 19 years old, and at least have it cleaned (at a rad shop) and inspected for leaks from corrosion. I had an exhaust hose overheat situation this summer on my new to me 15 year old Cummins 6BTA that was caused by a corroded “stock” Cummins elbow that looked similar to yours. Only caught the issue because I had just installed an exhaust heat alarm from Borel. It looks like you caught the problem before any real turbo damage was done.
Read Tony’s articles on exhaust systems and get a new dry elbow designed using all available height to avoid any seawater leakage in the future. Even the best elbows will eventually corrode through and you don’t want salt water in the turbo or worse yet the engine! A new gasket alone will not likely prevent this. I caught my problem just in time (luckily).
Either get Tony’s crew to design you a new exhaust or talk to Scott at NME.
I live near you (same weather), and just installed a Wolverine heater. Really easy to install and like it a lot so far.
Good luck,
Tom

[Kevin Carlson]

Tony, I pulled the risers because they were ostensibly 19 years old, so just for peace of mind. I think the rust is seawater leaking by the gasket since the port turbo has no rust.

Rob, I do not have any heat in the engine room, I will look into something this winter. Hopefully cleaning up the turbo surface will stop the leakage.

[Rob Schepis]

For sure if there is usable height in the engine room go ahead and use it. The higher rise is followed by a steeper drop and you always want to get the water away from the turbo as fast as possible. Seattle is top in the list as to humid regions, do you do anything to combat this in the engine room – Wolverines, low wattage space heater, etc ?

[Tony Athens]

1—————-What was the engine symptom or reason you decided to replace your risers? Let’s sort that out first

2——- For only 1400 hours, that’s quite a bit of rust in the flange area. You either have had external leaks above that ares dripping on the turbo, or some internal leakage getting to that area.. Luckily, is does not appear to be getting farther into the turbo..

3————-The newer graphite gasket will make for a better exhaust seal, but will not help if seawater is involved..

4———–if you are getting new risers or having them made, use all the height you have available to your advantage.. Anything less is wrong..

Tony

[Kevin Carlson]

I only have 1 poor photo showing the riser in place. It is a 37 Bayliner 1998 with 270 Cummins and 1300 hrs.
The risers are original from National Marine Exhaust here in the Seattle area.
I called them and asked if they could tell me the year and after sending him some photos of the stamping on the riser he said they were from the same era as the boat. (19 years). I have more room to have a higher rise in the riser but National Marine said I shouldn’t need it since I have water mufflers. The turbo blades look unaffected by water ingestion so I think the rust may be from leaking water.

[Rob Schepis]

Graphite Gasket

Here’s a link and pic

Cummins Graphite Turbo Charger to Exhaust Elbow Gasket

[Rob Schepis]

The graphite gasket is just for that, just block sand the mating face and you should be good to go. Why the rust? – Raw water leaking back due to improper exhaust design, poor (high humidity) ambient conditions, leaky deck above? What is the history (age) of the turbos and risers/elbows. Port some good pics of all hopefully to include the exhaust setup prior to removal..

[Author]

Replies