I had never tested because they were only a couple years old when I bought the boat with almost no time. Thought about skipping this year as well, but it was a rainy day so I spent a few minutes pressure testing. Starboard header on Port motor leaking.

Only reason I thought about skipping was because they are Big Tube headers with very little run time, this one is leaking at the Top, not down at the bottom where it bolts to the head. Strange.

A good reminder for sure.

I added 1/4 turn 316 stainless valves at the end of the water distribution tubes on all 4 of my headers, so that after flushing and cooling down to ambient temp, I can drain the headers, at least avoiding filling a cylinder while sitting.

Would a good internal ceramic coating as a heat barrier help guard against cracking? To me, keeping the heat away from the stainless would be a good thing. Anyone here tried this?

Are they on a stag motor setup?

I install -4 drains on all tube headers for just this reason. They tie together and dump out of a common thru-hull fitting (one per motor). The amount of water dumping off is not enough to negatively impact water pressure, but it's piece of mind for me knowing that if a header does develop an internal crack, it's not going to fill a cylinder with water.

Mine are on a side by side setup.

Skater, can you post a picture of your drains..?

Haven’t tested my CMIs since they went back in the boat. I’m afraid to say how old they are - not leaking.

But….

I also installed ball-valve drains at the junction from the heat exchanger to the distribution tube. After she cools down, she gets drained.

Interesting… when running, the valves can be open but will not drop water until they shut down. Have throught about converting to drains out of the transom using a similar setup to Skater’s.

When you say top do you mean at the collector?

As for drains I were going to put small 12V SS valves in wired to a switch so I could just drain, but it took 20 years for my E-tops to leak.

Skater, are you saying you dump a little water even when running?

Just get a nice set of stainless marine manifolds and never have headeraches again.

For me that would me no plug changes, PITA for a lot of other work. I am good with 20 years out of exhaust.