Water Ingestion

jitts3 said:
So it happens while running. I guess if thats the case then the valves don't close that tight. Always thought they did.
Click to expand...
Numerous causes of water ingestion.
#1 gasket between riser and ex manifold (pours in water)
#2 Riser rust out. (pours in water)
#3 exhaust manifolds rust out (pours in water)
#4 exhaust riser not high enough. (Water backflows into engine)
#5 wave surge or backing to fast (water forced back thru exhaust into engine)
#6 Valve overlap (Creates a vacuum pulling exhaust water back into engine)
#7 Condensation in exhaust( water drips back down into cylinder heads, Rusting vales and Cylinder)
#8 Leaving plug out ( boat sinks, Water pours in engine)

I can think of at least five more causes.
Risers,Gaskets,Exhaust manifolds are the #1 killers of marine engines.
Rumor has it,
A marine engine usually never wears out. They rust out, or have a water intrusion engine failure.

Knock on wood,
Ive only read about this stuff happening.
Other then my #6 cyl being 30lbs lower on compression then the rest. Rusty exhaust valve?
 
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Tail Chaser 661 said:
Knock on wood,
Ive only read about this stuff happening.
Other then my #6 cyl being 30lbs lower on compression then the rest. Rusty exhaust valve?
Click to expand...

Do a leak down test. Pull the plugs. Remove the oil filler cap. Turn the engine with a wrench until the #1 piston is at TDC as viewed though the plug hole. Connect your air compressor to the plug hole using your compression tester's hose and charge with 100 psi. If you detect a large leakage from the intake or exhaust system, turn off the air and turn the engine one full rotation. It might be at TDC following the exhaust stroke beginning the intake stroke, thus having the valves open a bit. You want it ending the compression stroke and beginning the power stroke, valves closed. If you still get a lot of leakage, check where the air is exhausting. If from the intake, you have bad intake valves. If from the exhaust. bad exhaust valve. If from the oil filler, bad compression rings.

To make the job easier, once you find TDC on the compression stroke for cylinder 1, do the rest of the cylinders in firing order. Then you only have to do a series of 90 degree turns of the crank to bring each piston to TDC.

Best regards,
Frank
 
fc3 said:
Do a leak down test. Pull the plugs. Remove the oil filler cap. Turn the engine with a wrench until the #1 piston is at TDC as viewed though the plug hole. Connect your air compressor to the plug hole using your compression tester's hose and charge with 100 psi. If you detect a large leakage from the intake or exhaust system, turn off the air and turn the engine one full rotation. It might be at TDC following the exhaust stroke beginning the intake stroke, thus having the valves open a bit. You want it ending the compression stroke and beginning the power stroke, valves closed. If you still get a lot of leakage, check where the air is exhausting. If from the intake, you have bad intake valves. If from the exhaust. bad exhaust valve. If from the oil filler, bad compression rings.

To make the job easier, once you find TDC on the compression stroke for cylinder 1, do the rest of the cylinders in firing order. Then you only have to do a series of 90 degree turns of the crank to bring each piston to TDC.

Best regards,
Frank
Click to expand...

Thanks Frank,:thumbsup:
Its really neat learning tips and tricks from you guys that actually went to school to learn all this.
Some of us just learn what we can by the service manuals.

It was actually two seasons ago last time I checked compression,
7 cyls were over 150psi one was down around 120 psi
Squirting oil in the cyl might have got me 130 psi. Engine was cold at the time.
Checking that the rotor is pointed at the #1 cyl in the distributor cab should also help confirm I'm on the compression stroke for the #1 cyl also. Correct?
 
Tail Chaser 661 said:
Checking that the rotor is pointed at the #1 cyl in the distributor cab should also help confirm I'm on the compression stroke for the #1 cyl also. Correct?
Click to expand...
Yes provided its "Cold Timed" Are you putting it back together or running now? Another way is to turn it over with the plug out. Place your finger over the hole and bump the starter. When the thing pushes air out. Its on compression stroke. If No. 1 look at the timing mark to get exact mark if needed.
What exactly are you doing with the engine?
 
Tail Chaser 661 said:
Thanks Frank,:thumbsup:
Its really neat learning tips and tricks from you guys that actually went to school to learn all this.
Some of us just learn what we can by the service manuals.

It was actually two seasons ago last time I checked compression,
7 cyls were over 150psi one was down around 120 psi
Squirting oil in the cyl might have got me 130 psi. Engine was cold at the time.
Checking that the rotor is pointed at the #1 cyl in the distributor cab should also help confirm I'm on the compression stroke for the #1 cyl also. Correct?
Click to expand...

You're welcome. But in school I learned calculus, topology, linear algebra, data structures, heuristic systems, and finite automata. The fun stuff I mostly learned at home from dad, picked up off the streets, and from manuals.

Sounds like your compression readings were about what I remember mine were. Really good (180-190ish) with two low, but within spec. I found enough leakage at the exhaust valves with the leak-down test that I decided to do the heads. My machine shop charges $175 for a big block head rebuild, so it's cheap enough to do on a lark.

Yeah, forgot about looking at the distributor to determine #1 at TDC of compression. I'm usually too lazy to pull the cap if I don't need to do it.

Best regards,
Frank
 
jitts3
I'm not really doing much with this engine.
Did a half ass compression test two years ago.
Just to see if she was ready to die. There is no knocks or ticks. A lifter just started ticking for about 5 seconds while cold after startup. I tried going a season on one oil change with some synthetic Diesel/Gas fleet oil.That may have loosened 24 yrs of sludge in the engine.
Bought the boat at a Consignment lot 5 yrs ago.
Boat was listed as being in perfect condition.
Not quite, Bad carb. Quadrajunk gummed up. leaky prop seal, leaky water pump. Still very nice boat.
I never got to pick the owners brain. Orig 1985 engine? Raw water cooled, Manifolds ever been changed?
I figure its the original engine with 780 hrs now.
Its a gas hog, 1.4 mpg and underpowered for this boat.
I also really dont trust the Alpha 1 drive for this boat.
I'm a low rpm diesel guy, I really hate the sound of a 5.7 screaming 3600 rpm just to be doing 24 or 26 mph if im lucky.
I'm going to save the extra 10 grand on buying a diesel and settle with a big block gas repower.
If I wasnt reading about some problems with the Volvo D4 260hp. Think I would pay the 28k. Dam thing is an easy fit, and gets 3.2 mpg in a heavy 26fter.

I was planning on another year out of my old 5.7 Maybe install new risers, lifters? valve job.
A Merc 8.1 Mag 375 HP 2006 crate engine dropped in my lap. 9950.00 A 4k savings.
I may wait till the off season for the install. I dont want to rush other upgrades to be done while the engines out. Besides, seems all I ever do anymore, Is sit there and admire the boat. Never even turning any wrenches :huh:
 
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Tail Chaser 661 said:
jitts3
I'm not really doing much with this engine.
Did a half ass compression test two years ago.
Just to see if she was ready to die. There is no knocks or ticks. A lifter just started ticking for about 5 seconds while cold after startup. I tried going a season on one oil change with some synthetic Diesel/Gas fleet oil.That may have loosened 24 yrs of sludge in the engine.
Bought the boat at a Consignment lot 5 yrs ago.
Boat was listed as being in perfect condition.
Not quite, Bad carb. Quadrajunk gummed up. leaky prop seal, leaky water pump. Still very nice boat.
I never got to pick the owners brain. Orig 1985 engine? Raw water cooled, Manifolds ever been changed?
I figure its the original engine with 780 hrs now.
Its a gas hog, 1.4 mpg and underpowered for this boat.
I also really dont trust the Alpha 1 drive for this boat.
I'm a low rpm diesel guy, I really hate the sound of a 5.7 screaming 3600 rpm just to be doing 24 or 26 mph if im lucky.
I'm going to save the extra 10 grand on buying a diesel and settle with a big block gas repower.
If I wasnt reading about some problems with the Volvo D4 260hp. Think I would pay the 28k. Dam thing is an easy fit, and gets 3.2 mpg in a heavy 26fter.

I was planning on another year out of my old 5.7 Maybe install new risers, lifters? valve job.
A Merc 8.1 Mag 375 HP 2006 crate engine dropped in my lap. 9950.00 A 4k savings.
I may wait till the off season for the install. I dont want to rush other upgrades to be done while the engines out. Besides, seems all I ever do anymore, Is sit there and admire the boat. Never even turning any wrenches :huh:
Click to expand...


In your decision making process, do you consider the amount you are looking to spend versus the likely resale value of the boat before and after the investment?
One option you mentioned above was $28,000. Even after this would be done the boat would have a hard time selling for $28,000.

That being said, last year I spend $8,500 adding a generator that likely increased the resale value by no more than a grand.
 
Tail Chaser 661 said:
Its a gas hog, 1.4 mpg and underpowered for this boat.
I also really dont trust the Alpha 1 drive for this boat.
I'm a low rpm diesel guy, I really hate the sound of a 5.7 screaming 3600 rpm just to be doing 24 or 26 mph if im lucky.
I'm going to save the extra 10 grand on buying a diesel and settle with a big block gas repower.
If I wasnt reading about some problems with the Volvo D4 260hp. Think I would pay the 28k. Dam thing is an easy fit, and gets 3.2 mpg in a heavy 26fter.
Click to expand...

A 26 foot boat with a single 5.7 is far from a gas hog.
 
1.4 mpg with a 100 gal tank is way off the mark.
I'm shooting for a Min of 220 mile range.
Seems everyone with a 26' or smaller boat is getting 2 mpg
with the New single screw EFI engines.
I have room for a couple of 30 gal aux fuel tanks mounted up against the aftcabin bulhead in the engine room if needed.

I can never recoupe my money, But I dont plan on selling.
I only want a trl boat. No slip fees and sitting in a corrosive environment
I do not want twins.
I'm 6' 6" tall. This boat has a 7' x 4' bunk in the aft cabin.
Its heavy,strong, with a good rough water ride.
Yet, Not so heavy to need twins or get good mpg with a upgraded single srew engine package.

My ideal boat might be a 28' pilot house fishing boat with a 6cyl diesel on a trl. That engine destroys sterndrives though.
A 7'L bunk in any fishing boat is vary rare to impossible to find. A boat like this is well over 150K also.

After crunching the numbers.
Spending 20k on a boat that suites my needs for the next 10 yrs or more. Seems like a good deal to me :huh:
Dang slip fees for a 26' in Calif is probably like 3500.00 a yr
 
Does anyone know if water ingestion was a problem on the mercrusier 7.4L MPI 310hp version not the Horizon. It has the older log style exhust system. Its a 2000 Sea Ray 34 sundancer Thanks Rich
 
I've had this problem two times. You should get the dry joint exhausts. they are merc only. Also make sure your pitch is correct after the elbows. My tech (sea ray, merc certified) made a couple of modifactions in order to have them fit.
 
If the failure is design caused the best way is to install lift mufflers. That is how Sea Ray finally fixed the issue after tinkering with extended risers as a quick fix that they tried first. But that's a very expensive route to take, so maybe trying the extended risers is the way to go for the 310DA. Most issues as far as I remember were with the early 380DA and 410DA with 454 Horizons which came with the "log style" exhaust.

If the failure was caused by wear ... well you got all the answers here ....
 
Hello all,

I'm new to the forum, joined about a week ago when I started looking at a 1998 310 with V drives. I've found alot of usefull information on this board and I'd like to thank you all.

I've got a question.....I've read alot about the water ingestion problems on the 310, did the 1998 with V drives have this same problem? The boat I'm looking at has 350 hours on the original engines and it has the "log" style exhaust. I have not done a compression or leakdown test yet, the owner is telling me it runs great and he's never had any problems. Can anyone tell me if this water ingestion is from a single "event" like coming off plane too fast or backing too quickly? What are the "dry Joint" manifolds and risers I'm hearing about. What is the approximate cost to retrofit with these?

Thanks again for any advice.

Chris
 
This boat does not have a generator installed. Has anyone had an ingestion problem on a boat without a genset? Perhaps the added weight of a generator drops the riser angle enough to allow ingestion???
 
I don't know for sure about your 1998. In addition to the log style muffler, the problem was worsened by an engine high performance camshaft change around that time, that caused greater valve overlap. If yours is the 350 MAG MPI rated at 300 HP, it is probably the later design. If you have an earlier design, with milder camshaft, maybe it's OK. You might be able to find out by calling Mercruiser with your engine serial numbers.
 
Trying to resurect an old thread! I am looking at a couple of 310's and I know one of them does have the log style exhaust. Can anyone let me know whether the dry joint exhaust will rectify this problem or go with the later mufflers? Trying to figure out a cost to rectify this. I know one of the boats I am looking at has had new engines installed. Waiting for a response as to why. Thanks for any help.
David
 
The only answer is the dry joint exhust. They will tell you that it will not fit on an o1. My tech (searay, mercrusier cert) did the job with out any mod's. I lost three motors to this and couldn't get sea ray to help me. Not to mention I asked "White Glove to give up his contact at sea ray several times but never got an answer.
 
My experience with this is issue is that the ingestion due to reversion was only a problem with the higher hp Horizon engines because of the overlap in the valve timing. However, the log style exhaust has been an issue with ingestion from the low angle of pitch on the long exhaust tube allowing the water to run back to the engine if you suddenly stop. Both can be big trouble. Mark
 
About to purchase 2001 310 Sundancer with 350 mag v-drives with 450 hours on the engines. Very concerned about the water ingestion issue. Any thoughts on what I should look for during survey of the boat?
 
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