Been there... this was the result. Destroyed the block too.

Those pictures look painful ...
I do hope that is not my problem.
I will tear into it tomorrow evening.

Thanks for all the input.

How many hours did your engine have on it when this happened? Thanks Scott

The engine has 256 hrs.

I started tearing it down last nite, I removed the header, & I did notice, what appears to be a small (3/8") hair line crack. It's at the bottom of the flange, where the the weld is. Both 6 & 8 show signs of water being in the combustion chamber, but I will know the whole story tonight when I get the head off. I hope this is something that just happened, & I've caught it before it destroys something.
I'm calling CMI this morning, hopefully they will be able to repair the header. It looks like it is very repairable, but looks can be deceiving ...

Do you boat in saltwater?

Biggus,
Thats the painful picture I was talking about we could put a quarter in one of the blocks damage !!!
Hard to tell how long it ran that way but must have been some time.
Hope its not the case for rangerrick63
Thumper

a couple of things to look out for... if water has been in those holes since last season, you are almost certainly looking at sticking the rings in those pistons . when you get the heads off you need to make a fixture and leak those two holes down individually before you have to have the heads off a second time. also.. it will often rust a valve in the guide and it will hang open slightly and you will see what you are seeing now...
brush research makes little mini valve guide hones that clean and refinish the guides beautifully and theyre cheap.

Got the head off...
#6 bent exhaust valve...
#6 & #8, signs of water in the combustion chamber, but it doesn't look like it's been for long.
It looks like I got lucky this time...
Would the water cause the bent valve?

I've called CMI to arrange to ship my headers to them to be tested & repaired. Hopefully I can get them out to them next week.

Heads are going to the machine shop in the morning for a valve job, springs, & most likely, valves.

I really appreciate all the input on this...The knowledge on OSO never fails to impress me

Is there any pitting on the valve stems???? Thats what happened to mine when Gils leaked. The water could cause a bent valve. Better a valve than a connecting rod.

Is the vale bent or tulip'd ? when they bend its more of a problem where it came in contact with something between it and the piston. Water could do this bit it usually tulips the valve and then it takes out the piston or it will drop the head off the valve and do real damage. These are problems that I have seem in my past.