Water ingestion motor problem need help

[Aponte]

recently purcahsed a 2000 38 Sundancer from a cousin that upgraded to a 46. When I purchased the boat I was told new motors were installed 2 years ago due to this water ingestion problem. Then this past winter new heads were put on ago to correct the problem along with all the updates from Merc and Sea Ray. I was just informed by my Marina that I Still have this problem and Merc has washed their hands of the boat. Now I need new motors and don't want to put the motors in if the problem still will continue. and why should I have to go for all this money for a design defect. can anyone shed some light on this subject

 

[SAshton]

what engines do you have? why was in ingesting water? faulty risers?

 

[fwebster]

There was a water ingestion issue on 1998-2001 Sea Ray 310-380's with 7.4L EFI engines. More than one factor or a combination of factors contributed to whether or not water ingestion occurred. The most common ones are engine design, specifically valve overlap, and engine installation and or boat design, i.e.engine and exhaust elbow height above the waterline and degree of incline from the elbow exit to the muffler inlet as well as muffler design (choice) and mounting height.

Some other boat manufacturers and Volvo-Penta 7.4 EFI packages also experienced water ingestion problems.

As you can see and imagine, there was and is a huge finger pointing exercise going on concerning who is at fault. By now, almost all affected boats have been fixed. The most common fix is a combination of a different muffler design, spacers to raise the riser or elbow height and even a different timing curve in the engine control module.

Everyone who has had their boats repaired with the above method seems to have solved their problem. I would suggest you go to your Sea Ray dealer and discuss the issue with their service manager and ask for help with the repair. If anyone will go to bat for you it will be the dealer since he is the only one who can bring any pressure to bear on both Mercruiser and Sea Ray. Besides, a Sea Ray dealer is going to know the best method and what parts are needed to cure the ingestion problem.

Good luck with it............

 

[Aponte]

I have 7.4 Mercs. I also have all documents indicating all updates were done. Such as, new risers with spacers, new mufflers new 7.4 motors and so on. There is a correct pitch as per Merc specs of 11 degrees on the exhaust hose to the muffler. We are figuring that the 8.1 Mercs will not have this problem. Is this true?

 

[PlayDate]

recently purcahsed a 2000 38 Sundancer from a cousin that upgraded to a 46. When I purchased the boat I was told new motors were installed 2 years ago due to this water ingestion problem. Then this past winter new heads were put on ago to correct the problem along with all the updates from Merc and Sea Ray. I was just informed by my Marina that I Still have this problem and Merc has washed their hands of the boat. Now I need new motors and don't want to put the motors in if the problem still will continue. and why should I have to go for all this money for a design defect. can anyone shed some light on this subject

I'm a little confused.... If new engines were installed two years ago to correct the ingestion issue why did they replace the heads last winter? The heads really don't come into play for this problem unless something got damaged. For the most part, boat builders get the geometry right on exhaust components and angles. On your model, Sea Ray/Mercruiser pushed the limit and subjected themselves to a lot of warranty issues. I'm guessing that the orgiinal design had the engines sitting higher relative to the operating water line.

I am really curious whether or not the correct spacers were installed on the exhaust manifolds two years ago to raise the riser height. Can you post a picture of one of your exhaust manifolds?

-John

 

[Aponte]

Here are some pics.. Aparently the problem was never really corrected even after Sea Raysigned off on the repair. I'm haveing trouble uploading pics. Maybe might be better to send over email...

 

[Sublimetime]

I have been battling the same problem for four years now.Are your motors the horizons with the half fresh water cooling system,meaning motor is fresh water cooled but manifolds and elbows/spacers are raw water cooled

 

[Sublimetime]

Frank, I have a 1989 390 ec that was repowered with these suspect 2000 big blocks.What would your solution be????? I already have the six inch spacers,aqua lift muffs way below the motor bottom line,with plenty of down angle in exhaust tube,

 

[Aponte]

Yes I have the 7.4 Horizons. I was told that the 8.1's do not have this problem. I have decided to go after Merc and Sea Ray this should have been corrected years ago. Something is really wrong when a boat has new motors all the updates required by Merc and Sea Ray and still the problem presists. I think their should be a class action suit against both Merc and Sea Ray....

 

[fwebster]

I wouldn't think you would have an ingestion problem with a 390EC. I owned the same boat for a number of years and loved it.....would still own the old girl had she been diesel powered.

For some reason, (the dealer thinks traffic and waterway crowding) we have never seen a water ingestion issue in our area. The thinking is that the traffic keeps boaters from chopping the throttles and stopping rapidly. The 390EC has exhaust outlets out the side of the boat and not where a stern wave can wash past the boat and cause water to run back into the exhaust seldom. With the distance your engines are from the mufflers and the angle down you have on the 390, even with radical valve overlap on the newer engines, I think the water stays far enough away from the riser exit that you are pretty much exempt from the problem.

 

[rondds]

what protects the older 390 EC? is it the straight drives (engine position) or the lack of underwater exhausts, or both? and if it is theunderwater exhausts, is it feasible to bypass them, create larger (4") above water-line exhausts?? cheaper than new engines i would think.

 

[Sublimetime]

believe me I am far from exempt previous owner installed motors spring2001 fall/spring 2001 merc warranteda longblock port side.spring 2002 froze valve in guide/broken push rod. on starboard. spring2003 froze valve broke pushrod starboard side.At this point they insist i'm not winterizing properly.(from first year to present I always winterized according to their bulletin about special fuel mix in seperate container)spring 2004 froze valve and totally rusted out seat.everytime I have removed the manifolds you can see the water/rust damage on the inside of the exhaust side of the manifolds,even after they have been replaced with brand new onesjust a few months later all rusted inside exhaust side(definetly not riser gaskets leaking) I think the raw water cooled manifolds and long nowake zone back into the marina causes manifolds to cool down greatly(motor at 185degrees but i can keep my hands on manifolds as long as I would like to they are so cool)thus the slightmist of water being sucked back in because of the valve overlap does not steam off out of the exhuast ports and then runs downinside of manifolds and collects on valve stem and seats.never enough to hydro lock but plenty to keep it moist in chamber and ports and cause all kinds of rust and seizing

 

[Sublimetime]

It seems that the damage is done during the summer but does not get achance to seize because I use the boat so often but when it gets to sit without being turned over each week things tend to bind up.Then in spring when you crank first time something breaks.For past three winters i have been removing manifolds after winterizing and coating valve stems from exhaust port side.seems to work but WAY to much work.

 

[SAshton]

I just bought a 98 25'' Sundancer with the 7.4L MPI. I am changing the manifolds & risers come spring. I think I'm ok but is it just the larger searays with that water ingestion issue?

 

[PlayDate]

Here are some pics.. Aparently the problem was never really corrected even after Sea Raysigned off on the repair. I'm haveing trouble uploading pics. Maybe might be better to send over email...

When you have a moment, send the photos to:
playdate@verizon.net

These things always come back to what was done right and what was done wrong. The 7.4 and 8.1 are structually similiar (block/heads). As previously identified, the cam and engine management systems are different. However, if the exhaust system design is questionable, it spells problems with both engine types. Virtually all gas engines have an overlap on the cam profile....some more severe than others. I don't know the particulars for your original engines or the ones which were installed two years ago. That would be interesting data to take a look at. Do you have any insight as to why they replaced the heads last year?

Sublimetime's experience is also interesting. I'm really curious as to which engine and cylinder the problem occured on. Upon taking things apart, was everything rusty or only a few cylinders?

-John

 

[Hampton]

You guys make it difficult to read. The only Sea Rays with the water ingestion problems are larger than 25". Also, I think they are all inboards. (Experts chime in.)

 

[rondds]

i'm trying to get confirmation that it is only on certain later model SR inboards, all of which feature SR's hybrid underwater/above water exhausts. my friend's 350/370DA (1990) as well as my 1989 340DB have only above waterline side exhausts and, i believe, are unaffected by these problems. outdrives are also unplagued by these problems.

 

[Sublimetime]

rondds-Its not so much the year of the boat or the manufacturer is as much it is the year of the motors.I know two other people with diff. boats but same motors and having issues. My boat is 1989 but motors were brand new replacements in 2000,not a rebuild. Before the repower with 7.4 mpi horizons 385 hp. the boat had original 7.4 carbureted 340 hp. mercs wich never had any problems, other than they had over1400 hrs on them when replaced. The last 3 years merc made the 7.4 mpi they bumped up the horsepower to 385 by using the longer duration cam,and switched to a half fresh water cooling system from the full system they used prior and also switched back to when they started building the 7.4 replacement the 8.1..
PlayDate--My motors are set up as straight inboards..they have a pretty good tilt, rear of motor to stern.It is always a valve/port that is directly under the center of the manifold closest to stern in other words cylinder more in 5&6 some in7&8 and one hung valve in hole 4. This is what leads me to the cold manifolds condensating and dripping it straight down.
My guess as to why they replaced his heads again last year is that the area around the valve seats rusted out, stopped sealing,and on the intake stroke it sucks moisture back up from wet exhaust and process gets worse and worse.
Not an under water exhaust issue either as my exhaust is above and out the side not rear

 

[PlayDate]

Sublimetime, I agree with you. Although, yours is the first I have heard of having a problem with side exit exhausts. There is very little backpressure with side exits. I usually see the condensation you are talking about on go boats when uneven temps and different metals cause condensation to form.

Aponte sent me some great pictures which shows the problem he is dealing with. Hopefully he will post them. They clearly show the effects of water entering/forming on the inside of the spacer.



-John

 

[Aponte]

OK I just figured out what I was doin gwrong on the up load of my pics. So, Here are the pics of my water ingestion probelm. Everybody please comment. Thank you Anthony