stevel

Water was in the exhaust manifold against the exhause valve. As you turned the motor over more water entered after each time the exhaust valve opened.
This water would still be in the inner manifold passage even after you drained the outer passage.

Two possibilities:

Bad gasket between your manifold and the riser that is allowing water to go from the outer passage (water cooling passage) to the inner passage (exhaust only).

Rusted or cracked manifold or riser. Very probably after that many years. Especially with any salt water use.

Make sure you check the other side. If one side went, the other side is usually not far behind.

Change the oil. Oil floats on top of the water so you will never see it on the dipstick. You will probably find at least a quart of water in the oil pan.

Your motor should be fine if you caught all of this quickly.

Stephen

Phazar454Mag

I haven't made a compression test yet ... need to buy a compression gauge first. I did not have time today to remove the elbow, but I do hope it could a small leak between the elbow and manifold. When I mounted the elbow I used an original gasket (silver) and torqued the bolts to the specification outlined in the Clymer Mercruiser shop manual. I am wondering whether I need to use any gasket sealant on the "silver" elbow/manifold gasket ? Also I am thinking may be the torque specification has changed when using the new gasket type ... anyone know what Mercury specifies as tightening torque for the elbow bolts ?
Thanks for the inputs ...... much appreciated.

Panther

I never followed the torque spec on that. I have used Aviation sealant by permatex to seal the manifold from time to time. Just tighten it up pretty tight.

Phazar454Mag

Update: I checked the exhaust elbow/manifold connection again and it was OK. Did a compression check and all cylinders were between 160-162 PSI except for one at 152. After every run I checked for water and only cylinder number 4 had a few drops of water, but after the last run and the boat had been sitting for a couple of days: Water in all cylinders again. This means that water was entering the engine after having been switched off, because I had pulled the plugs and done extensive cranking to get the water out of cylinder 4 after the last trip. I then decided to remove the cylinder head, and it was quite a challenge for me since I have never worked on my 454 Mag before this problem. It was not that difficult to remove the head, and after some time I found a very small hole (crack) in the exhaust port of cylinder 4. I used a small screwdriver to test the area around the hole and it quickly became much bigger. Can't believe how fragile it is. I find it difficult to understand if this could be cause by corrosion or whether it is a problem with the casting ? The rest of the head looks just fine.
A new cylinder head at the dealer is a rip off here in Denmark, so I need to think about my options now. If this engine should be repaired I would consider to replace: both heads and exhaust, intake and another cam.

Cord

iTrader: (2)

This is the result of corrosion. Because the head rotted out (which I never heard of) I'd be very suspicious of the intake manifold and the block. In all honesty, I don't know if I would spend the money to put this engine back together. Who knows when the block is going to fail? Shop for a complete engine over here and then arrange for it to be shipped over.

cuda

Corroded heads are not uncommon at all if you are in salt water. You can by rebuilt heads at a pretty good price.

cig1988

Phazer, Look in the parts swap section. 38cigmike has 2 sets for sale. You have the #990 castings which is the last 3 digits of the casting#. Do yourself a favor, pull the engine and freshen it up. If salt water has been in the crankcase chances are good you have rust contamination. You may have a rusty journal or over time your oil pump may pickup crap and wipe out your bearings. This is what happened to me recently.
Cuda is right, this is not uncommon. I had a set of merlin heads that rotted out in 5 years.

1989Phazar

Hey I have a 1989 Doral Phazar. I am the third owner and the original engine was a 454Mag 365 hp. Now the engine is dressed up a bit and had a stroker kit put in it and is bored out to a 502. It is running around 450 to 550 hp. She will run around 75 - 78 mph. Im just interested if you could send me some pictures of your doral phazar my email is [email protected]. If you want you can see some pics of mine.

Phazar454Mag

I sold my Phazar October last year, but I can tell you that I was real happy with it, I just wanted something bigger and newer. I ended up buying a Formula 292 Fastech. Because of the engine trouble as per this thread with the Phazar, I ended up installing a used 454 Mag MPI from 1999. Top speed was 68-69 MPH GPS just bouncing the rev limiter, and I think that is pretty good considering that it is bottom painted. I think a few more miles would be possible with a little lab work done to the prop. I sold it to a friend so I still see it around where I go boating. It looks great when traveling at high speed. And generally I think the Phazar is so much nicer than a Sea Ray Pachanga 22. I will be happy to email you some pictures.

1989Phazar

Yes the sea ray 22 pachanga is not near as nice as the doral phazar. I just bought mine 2 weeks ago and it has a new paint job also. But the top of the boat (white) is dull just from over time like it is still nice but I would like to bring out the shine, and from your pictures it looks like you had a nice finish. How did you keep yours nice. Also in mine there is no snap in carpet so I want to get one made. I'm surprised your upholstery looked really nice. Mine has some minor tears on the engine hatch (sun pad). It looks like you replaced a part of your sun pad. If you have replaced any upholstery could you tell me how much you paid because I'm thinking of getting the whole back sun pad redone. Thanks Alot