water under engine bilge 36 sed bridge

Fitzroy

Fitzroy

New Member
Jan 5, 2008
37
sydney australia
Boat Info
36 sedan bridge
Engines
380 qsb
I get quite a bit of water in the bilge area under the engines when it rains( both sides). It fills up and cannot drain to the main bilge area which has a pump located between the engines. (I cannot believe there is not drain to main bilge from this site) I have 380 qsb 07 build. The dealer has had a few goes but cannot find out where the water is comming from. I suspect it might be comming from the side vents. I am going to test this theory next time it rains. Has anyone with this model experienced similar problems Thanks sydney australia
 
All of the stringers have limber holes through them for water to make it's way to the center of the bilge. Limber holes are usually tubes that go through the stringers. This is specifically so your situation does not occur. However, these holes get plugged easily with crap and stuff that finds its way into the engine compartment. You need to find these holes and open them up. One way is to shape a wire coat hanger and feel your way along the bottom edge of the stringer. You'll find them eventually depending on how much room you have to move around. Once you find them you can poke them clear with a long screwdriver or anything else that works.

Good luck.
 
I don't know if this is a design point or not but the 480 DB does not have drain holes for the compartment right under the engine. I would guess that the under engine area would hold 6 or so gallons before it would spill over into an area that does drain into the lower bilge.

When my boat was new I had the port side engine oil pan gasket fail (I assume the bolts all vibrated out but I digress) and had oil drain into that area. By not having it drain into the bilge directly, the oil leak was contained and didn't crap up the whole bilge which made it much easier to clean up and also didn't dump oil overboard.

It's also an area that will capture antifreeze and I'm sure you'd rather see it as opposed to it just getting dumped overboard.

I'm not sure I would go drilling holes such that the area will drain. That's a can of worms you don't want to open.
 
Later boats have sealed compartments under the engines/transmissions for just the reason Gary mentioned. I certainly don't know about requirements in Australia, but in the US your boat wouldn't pass a boarding inspection if you added limber holes to the bulkheads under your engines.
 
My bad on the limber holes. I have them on my '89 and assumed they all had them. that's what I get for assuming.
 
Specifically, the 36 Sedan bridge definately does not have any drain holes in the bilge area under the engines. I have had to pump water out of them several times for various reasons, and I have looked long and hard down there for an easy way to get a few gallons of water out, but it is designed is to hold the oil and fluids that should not be pumped out overboard...it is just a pain when regular water gets in there, and you need a quick fix to get rid of it.
 
I keep a small shop vac in my lazarette area and it's primary use is to pump water out from that area (after checking impellers, etc.).
 
I have a 400 sedan bridge and have the same problem but water is mostly under the Port engine. After checking it out it seems to come from the stairs to the flight bridge area..

I watched i droplets of water dropping onto the large round exhaust manifold onto the
mounting platform and falling into the area under the engine..Since the manifold is half way between both bulkheads I thought I could make a silcone ridge on the platform to guide the water in to the bilge..I haven't done this yet...

I also removed the cockpit fridge to see where the water was coming from and found a pass through for the water to drip down to the bilge area..

In th end I just purchased a 5 dollar hand pump form Whitworths (Austrtalia) Isimilar to "West Marine"

cheers

Iballs (Ozzie-iv)
 
Thank a lot for your responses. I did not appreciate the issue of an oil spill or other contaminants being contained. That makes sense. I have purchased a small 12V pump to pump out to main bilge area. I had the dealer remove the side vent and investigate, there is water in the bottom of the vent in that area and it leads directly down the side into the pockets at the sides of the boat which leads to the bilge under engine. We have made a small modification to cover up about half the bottom of the cut out and replace cover. Hopefully this would stop water getting in through the vents and allow enough air circulation. This also ocures when off shore and waves hit the sides the water get in through the vents and into the bilge underneath the engines.
Thanks for all your comments.
 
I would consider running your Bilge Blowers while crusing until you have a good idea of how much of an effect that may have on air flow. I run mine anyway.
 
I'm not sure I would go covering up any of the area that air needs to get in. That could really hit your performance of the engines. I know my QSM-11's are a little air starved at cruise with the vents that are on the side of the 480 DB. My engines suck in about 900 CFM (per engine) at cruise and the boost pressure on the port engine is always a little below spec and also below the boost pressure of the starboard engine. If I open the engine hatch at cruise, the boost pressures on both engines rise to spec. If anything, I need to make my intake holes bigger... Ever seen the intakes on the side of the hull on a Viking? They are HUGE! and I doubt they have water intrusion problems with them... hmmm...

The blowers won't do poop for you... A *BIG* blower will give you about 200 CFM (in real life) and if the percentage area it is consuming on the intake becomes too high, it'll end up being "in the way" of the massive amount of air the engines are trying to suck in.
 
Gary, you need to install a hood scoop...Oh man, I can see it now, swept back antenna and a big honking hood scoop right in front of the sun pad...AWESOME..then some flames on the side........or maybe a racing stripe right doen the centerline......WOW
 
Well... it's too early in the morning... I forgot that blowers "suck air out" and don't "blow air in" so running the blowers is going to remove precious air from the engine room... Running blowers will hurt you and not help you.

Duh.

I only run the blowers when the engines go to idle after running them for a period of time. All blowers do for a diesel boat is cool the engine room down.... they don't have any other use.

Maybe I'll just put a big ugly screen door on my engine room hatch.
 
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The first thing that popped into my head when I read of modifications that restricted air flow was to increase air flow through the engine room. If a 200 CFM blower affects the performance of the engines, then I was right.
 
This has been my worry air flow. However The modification will still allow the same volume of air to enter the engine bay. I am only covering the bottom half of the outside of the vent. If I need more air I will have to add small vents in the cockpit area (on either side). I cannot stand the fact that I have to pump water out every time it rains or every time we go off shore. I use the boat almost every second weekend, through out the year. In sydney winter is mild and you can get beautiful days sunny and 22 to 24 Centigrade in winter not all the time of course.
 
Sydney is beautiful. I had the opportunity to visit twice while stationed in Japan. Do you remember a cat 5 cyclone that was heading to shore up near Townsville in late '96? We had to deploy down to Williamtown (I think - near Newcastle) to keep the jets safe from the storm. We spent 5 nights in Sydney, sitting the storm out.

Then, after 1 good week of flying out over the barrier reef, the storm turned around and headed back toward shore. We had 2 hours notice over night on a Friday to evacuate the jets over to Darwin. One stayed behind, stuck in the mud off the end of the runway (my #4 wingman from the first week of flying). Belinda Carlisle (of Go-Go's fame) was staying in the suite next to us at the Sheraton Casino in Townsville. We had to stuff a wet towel under the door to keep illicit fumes out of our room. You know all those Chevelle's and similar cars in Australia (at least 10 years ago)? The ones kids hop-up? They are like 2/3 scale, 4-door versions of the ones we had in the US in the 70's. It was like a time warp. It was really cool to see those rides.
 
I am glad you enjoyed Australia. It is a great place. Sydney is a great spot for boating you have a couple of river systems and bays 20-50 natuical miles north and the same down south. We have a group of friends that we boat with and have great times rafted up at places like port hacking, or Hawkesbury. I used to have a chevy 3500 dually silverado when I used to tow by old bayliner 265. Most cars are now small and aisan built due to the fuel prices. Diesel at my marine is aud$2.10/L ie $7.94 /usgal at .92 that is usd$7.30/usgal. I buy from a barge that sells at aud$1.64/L. This is why almost all boats above 36ft are diesel.
 
Have finally resolved the issue with water in the bilge area. Two problems existed one was rain water and the other sea water. With the sea water it was found that both starboard and port side idle exhaust hull fittings were leaking and letting sea water in. Also found that the drain fitting and one bilge filling on port were leaking. The vents definitely let rain water and offshore spray into the side pockets and into the bilge. We are making a new vent system with the same air flow volume but without the vent louvers just a larger opening at the bottom of shroud. The dealer in sydney is very good and is rectifying the problems immediately. I still have some water comming from the port side down lights in the saloon when it rains. The dealer is trying to find the source of this water. Any ideas or similar experiences please let me know
 
Check the caulking around the front windows. I had a couple leaks in the caulking around the window which let some rain water in as well as some sea water when we were in rough seas. If that is the case, insist that the dealer take out the entire windshield, and re-set the whole thing. My dealer put additional caulking around the window as a band-aid until the off-season when they were going to pull the windshield out and re-set, but that caulking only lasted a few weeks before leaks started again. FYI, in my boat it was also the port side, and the leak was coming from the lower part of the front windshiled. Any questions, let me know.
 
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