Archive for the ‘Marine Cooling Systems’ Category

The Yamaha SX230 is a sport boat that utilizes the “Jet” style propulsion. Therefore winterizing this particular model of sport boat differs form Sterndrive or Inboard model boats. As always we want to point out that you will need to verify your manufacturer’s recommendations before starting the winterization on this boat. However as with all boat models the basic requirements of winterization stay the same since you are preparing the boat and engine for over the winter storage.

The Mercruiser 5.0L MPI was originally produced with several different draining options. Therefore the Winterization on this particular motor does depend on the draining system your engine is equipped with. The basic requirements of Boat Winterization will differ from manufacturer to manufacturer so you do need to read and understand your manufacturer’s specific requirements.

Winterizing Inboard model boats differs form the traditional sterndrive boat models in that the maintenance steps associated with the Sterndrive or Lower Unit are not required. However on Watersport model boats such as Tige’, Malibu, Correct Craft and Mastercraft they are commonly equipped with Ballast systems which require special treatment in preparing them for winter storage. This video will guide you through all of the normal steps associated with Winterizing your Inboard model boat.

Mercury Outboard Water Pump Diagrams…READ MORE

Regularly scheduled Outboard Motor maintenance is one of the most important factors in determining the life expectancy of your engine. All of the outboard motor manufacturers including Mercury Marine, Yamaha, Suzuki and Evinrude recommend inspecting, if not replacing the water pump impeller every 1 to 2 years. It’s worth mentioning at this same time that the Inboard and Sterndrive Marine Engine manufacturer’s such as Mercruiser and Volvo Penta also recommend these same water pump impeller maintenance procures on their Marine Products as well.

When you think about the design of the standard open style Marine Cooling system you have to think about the various items that can end up getting picked up by the water pump and end up inside of the motor. Depending on the conditions you operate your boat within its not uncommon for boaters to suck up plastic bags, grass, weeds, etc all of which can limit the amount of water to the engine. The most common way a boater realizes this happening is when the alarm sounds and they shut down the motor. However by the time the alarm sounds damage may have already occurred. Understanding that this damage is cumulative in many cases, it sheds light on the importance of maintaining a properly functioning water pump impeller and cooling system. Understanding that the water pump by design functions by utilizing a specific amount of “controlled” friction between the water pump body and the impeller.  As the blades of the impeller are deformed the area changes which in effect allows the pressure to be lowered as the area inside of the pump changes from smaller to greater. This lower pressure differential is what allows water to flow in the direction from higher to lower pressure. Alas the functioning of the positive displacement water pump. However once water is limited to the water pump this friction increases exponentially between the impeller and water pump body which then introduces heat, and ultimately the breakdown of the water pump impeller. Once this happens the material characteristics of the impeller change and are such that it is no longer able to create the needed “low” pressure draw to pump water as it was designed.

Regardless of whether you run a Mercury Outboard Motor, Yamaha 4 Stroke Outboard, or Mercuiser Sterndrive motor proper cooling system maintenance is critical to the longevity of that product.

There’s nothing like zipping across the water at 60 Mph with the sun in your face and the wind in your hair. You own the lake when you’re on top of that Sea-Doo. You don’t miss the cold weather at all – you’ve got your “Croakies” on and you’re strutting on down to the dock. Just dust that beast off and let ‘er rip.

Not so fast.

Did you winterize your jet ski? If so, it’s time to de-winterize. If not, you need to bring it into the shop.

Before you do anything else, check the lines and clean the body. Run your fingers up and down the fuel line to make sure there are no cracks or thin, pre-cracking areas that wore down during winter storage. Don’t forget to check the cooling lines as well. Jet skis that have been in storage for several months will almost always require a thorough cleaning since they’ve likely gathered dust and cobwebs. Most importantly, make sure the exhaust is completely clear to avoid overheating and other engine problems.

Check spark plugs for rust and carburetors for dust – these substances are highly dangerous for their respective parts.

Hopefully you filled the gas tank with fuel and a stabilizer last fall when you winterized to prevent damage to the fuel system over the winter. If not, take your jet ski to a professional right away. The more prep work you did before the winter, the better shape you’ll be in when you take your baby out of storage. Empty the gas tank and run fresh fuel through the engine to find any clogged areas. Either new fuel or a fuel protecting agent such as STA-BIL can help.

Okay – now you can get out there and show the lake who’s boss.

 

Question: Can you explain what the purpose is for Mercruiser’s Water Distribution Housing most of the Marine Engines are being equipped with today?

When popping the engine hatch and looking at the front of a typical Marine Engine today, one can’t help but notice the abundance of cooling system hoses the engines are equipped with these days. On the surface it seems much like just about everything in our lives where things just continue to get more and more complicated while finally reaching a point that the typical do-it-yourself garage mechanic can no longer service his own products.  In the case of Mercruiser’s Water Distribution Housing while the feature does add complexity in one aspect it does simplify things in another.

Even as far back as the early 1980’s Mercruiser had the desire to develop a Marine Engine equipped with an automatic draining cooling system. The Mercruiser 3.7L 470 Marine Engine, while not equipped with an automatic draining cooling system did in fact have many of the features that lead to the systems in place today. While an automatic draining system sounds fairly doable on the surface the typical issues of cost, liability, etc always stood in the way from allowing them to accomplish this feature. The main concern with an automatic draining cooling system was the liability that arises from any resulting freeze damage. The existing approach puts the responsibility of th owner to visually verify if complete draining is occurring from each drain location. If any question arises as to whether or not complete draining is occurring the owner is to use a small screw driver or piece of wire to clear out any obstructions to the drain. With an automatic system this responsibility then falls back on the manufacturer however even if the drain valve itself operates correctly the issues still remained that the drain hole could be obstructed by debris, etc. Therefore in the late 1990’s and early 2000’s Mercruiser set out to develop a better cooling system with regards to ease of draining. While these latest systems are not completely automatic they do in fact allow draining without the common challenges of standing on your head while removing block drain plugs, manifold hoses, etc. Mercruiser offers several different Drain System options including the multi-point drain, the single point drain, as well as the air actuated single point drain…READ MORE

 

Select this link to read more about other related drain system patents…..READ MORE

** CLICK ON IMAGE TO ENLARGE**

Question: Do the Mercruiser Engines equipped with the Dry Joint Style Exhaust AND Closed Cooling systems circulate antifreeze through the exhaust manifolds?

Answer: Mercruiser has made changes over the years between 1/2 and FULL cooling systems. The driving factor for this was the same reason that always seems to govern manufacturers and their products; cost.  Up until 1992 Mercruiser had almost always configured their marine cooling systems, both raw water and fresh water cooling systems, such that they included warm manifolds. However in 1992 when Mercruiser introduced the 502 mag EFI motor the intake plenum was so large that it interfered with the standard thermostat housing and therefore prevented them . Therefore Mercruiser set out to determine if there were functional issues to back up the concerns that the exhaust manifolds could not be allowed to run colder than engine temperature. Mercruiser performed a significant amount of functional testing with the cold manifold systems and the resulting effect of condensation. They determined through this testing that no functional damage resulted that could be attributed to the cold manifolds. Therefore starting in 1992 with the introduction of teh 502 Mag MPI Mercruiser offered the first of several engines with the cold manifold style cooling system.

However around the 2000 model year Mercruiser realized that the cost of warranty related to condensation induced engine damage had escalated significantly over the past 8 years and was becoming a real issue. Therefore when the 8.1L engine was released in 2001 it was determined that there was no achievable way to introduce this new engine with a warm manifold type cooling system. Therefore several specific system designs were implemented on this engine to allow it to also be released with the cold manifold type cooling system. However in 2002 the decision  was made that going forward all new designs would be done while including a warm manifold cooling system unless this was just not possible.

Cooling Flow Diagram: Therefore referencing the above flow diagram we want to point out a few of the following Mercruiser specific features:

1. Reference Item “C” Check Valve – This is a patented feature offered by Mercruiser. Since Mercruiser offers the easy to use Single Point Drain system’s they have to take into account  that preventative features are required to prevent water entering the boat when the draining is underway. Historically this was done manually when draining was performed with the boat remaining in the water by using a manually operated ball valve.
2. Reference Item “G” Distribution Housing – This patented feature is specific to Mercruiser and required  to support the single point drain feature. All of the incoming water is tied into a centrally located housing which can then be used as a location for draining. Note that a derivative of this housing is used with the raw water or open cooling systems.
3. Reference Item “I” Thermostat Housing – Mercruiser utilized a full flow thermostat housing that direct flow through the heat exchanger or through the bypass circuit at all times. This is a key feature of Mercruiser Cooling System in that regardless of the thermostat position, the engine always experiences 100% coolant flow. This is important to engine operating efficiency because it’s not always the coolant temperature rather the coolant flow that determines if and when detonation occurs. Therefore an engine with maximum flowrate through the cylinder heads offers the best opportunity for achieving the maximum spark timing.

Topic: Water Pump Failures

Question: My Mercruiser Marine Engine suddenly started overheating to the point I’m afraid to run the engine. I watched your video on replacing the water pump impeller and in fact narrowed my problem down to a failed water pump impeller on my 807151A14 water pump impeller. However after replacing the impeller the engine is still overheating. Did I miss something when replacing the water pump impeller?

Response: This is a very common situation however its very important to understand why. This is probably one of the most common situations a marine mechanic faces while addressing marine cooling system related problems. It can be described like the chicken and the egg scenario regarding whether the failed impeller causes the overheat or the lack of water flow/overheat causes the impeller to fail. Regardless of which happens first the result is always the same; a failed water pump impeller.

• Situation 1 – You’ve been running all summer while noticing your temperature slowly climbing over the course of the days/weeks. Ultimately you reach a point where the engine overheats and you can no longer run. The image below illustrates an oil cooler that has become plugged with grass, weeds, trash, or some other kind of foreign debris. This typically comes as a result of operating in an environment where grass or weeds are common, however it can also be attributed to picking up a plastic bag over the water intake on a sterndrive. It is important to know the operating conditions of the area you operate within so you can schedule your maintenance in accordance with this. In the case described here it is likely that the cooler became plugged over a period of time which lead to the slowly increasing engine operating temperatures. Ultimately this can lead to impeller damage from the lack of sufficient water flow until the impeller ultimately fails. It is important that you inspect all of your coolers each season when performing your normal winterization maintenance, or if you live in an area where you do not winterize you should schedule time each year while inspecting the water pump impeller to also inspect the coolers for blockage.

• Situation 2 – You’ve been running all season long with no apparent temperature related issues. All of a sudden your engine overheats and forces you to shut down. After inspection you determine the water pump impeller has failed. Its important to realize how a positive displacement pump functions and displaces/pumps water. These pumps move water by creating a pressure displacement (low pressure) on the inlet side of the pump while then producing positive pressure on the outlet side. This process in effect then moves water. These pumps commonly have a pliable, rubber impeller that has an offset section which compresses certain veins of the impeller to create the pump suction. If the internal surface of the pump body becomes grooved or anything other than smooth the impeller loses efficiency and therefore loses its ability to move water. In this case with a rubber impeller the pliable material of the impeller which cannot absorb heat tends to break down therefore becoming less pliable to the point that it actually becomes brittle much like when you burn a piece of rubber and it becomes hard. At this point it is like a self-perpetuating condition in which the increasing heat is leading to further breakdown which then continues to decrease the performance of the pump until failure results. Whats important to realize in this case is that many of the broken/missing pieces of the failed impeller get trapped somewhere in the cooling system and cannot exit the system. While this is a more common of a problem on closed cooling engine or any engine equipped with an engine oil cooler it can also lead to problems on raw water cooled engines NOT equipped with any coolers.

 

 

Conclusion: Whether you have an impeller fail which then leads to overheating or you have a blockage in the cooler that leads to impeller failure you should always check the complete inlet and outlet flow paths to ensure there is nothing blocking the system from good water flow into and out of the water pump.

 

Draining the Seawater System

Between the years of 1998 and 2001 Mercruiser decided to target the market regarding marine engine draining with specific focus towards making this step easier for the consumer. The thought behind this was that making the process of draining the engine more simplistic had the possibility of lengthening the boating season in areas such as the Midwest where cold weather normally precedes the actual winter months by several weeks if not months. This decision was a delicate balance for Mercruiser due to the fact that a large portion of their dealer network is located in areas that cannot boat year round and therefore these dealers look to the winterization process as a revenue stream leading into the slow winter months when their service departments really slow down. The other major concern was that by introducing a drain system opened the possibility to freeze damage being pointed back at Mercruiser. With the current process of manually removing plugs the customer is ultimately responsible to verify that the coolant drains once the plugs or hose is removed. However with a drain system means any given drain line could plug individually and therefore the customer would not be able to determine if a specific individual component had drained properly.

Therefore Mercruiser developed and patented a variety of drain systems that essentially function the same however offer a different means of activating the drain depending on the complexity of the actuation design.  The drain system functions by connecting all of the required drain points into a single manifold for draining. However the drain points all incorporate patented features that prevent them from plugging with debris. The below article and video walk through Mercruiser’s manual single point drain system.

**CAUTION**

Water can enter the bilge when the drain system is open, damaging the engine or causing the boat to sink. Remove the boat
from the water or close the seacock, disconnect and plug the seawater inlet hose, and ensure the bilge pump is operationall
before draining. Do not operate the engine with the drain system open.

IMPORTANT: Only drain the seawater section of the closed‑cooling system.
IMPORTANT: The boat must be as level as possible to ensure complete draining of the cooling system.

Your power package is equipped with a drain system. Refer to Drain System Identification to determine which instructions apply
to your power package.

IMPORTANT: The engine must not be operating at any point during the draining procedure.
IMPORTANT: Mercury MerCruiser requires that propylene glycol antifreeze, mixed to the manufacturer’s instructions, be used in
the seawater section of the cooling system for freezing temperatures or extended storage. Make sure that the propylene glycol
antifreeze contains a rust inhibitor and is recommended for use in marine engines. Be certain to follow the propylene glycol
manufacturer’s recommendations.

Drain System Identification

Manual Single‑Point Drain System Boat in the Water

1. Close the seacock (if equipped) or remove and plug the water inlet hose.
2. Rotate the blue handle counterclockwise until it stops (approximately two turns). The red on the handle shaft indicates that the drain system is open. Do not force the handle as this will create new threads.
3. Immediately remove the blue drain plug from the side of the thermostat housing. This must be removed within 30 seconds to properly vent the cooling system.

4. Visually verify that water is draining. If water does not drain, remove the blue drain plug from the distribution housing and drain manually.

1. Allow the system to drain for a minimum of five minutes. We recommend leaving the drain system open while transporting the boat or performing other maintenance.
2. Reinstall the blue drain plug in the thermostat housing.
3. Close the drain system by rotating the blue handle clockwise until it stops and install the blue drain plug, if removed. The handle is fully seated when no red is visible. Do not overtighten the handle, as this action will create new threads.
4. Open the seacock (if equipped) or unplug and reconnect the water inlet hose before operating the engine.

Boat out of the Water

1. Place the boat on a level surface to ensure complete draining of system.
2. Rotate the blue handle counterclockwise until it stops (approximately two turns). The red on the handle shaft indicates that the drain system is open. Do not overtighten the handle, as this action will create new threads.

3. Visually verify that water is draining. If water does not drain, remove the blue drain plug from the distribution housing and drain manually.

1. Allow the system to drain for a minimum of five minutes. We recommend leaving the plugs out while transporting the boat or performing other maintenance to ensure that all water is drained.
2. Close the drain system by rotating the blue handle clockwise until it stops or installing the blue drain plug. The handle is fully seated when no red is visible. Do not overtighten handle, as this action will create new threads.

 

Dennis,

Yes we do handle the OEM kit from Mercruiser as well. Using the link below you can add your selected product(s) to your shopping cart and the shipping estimator located at the bottom of the shopping cart page will give you a shipping cost based on your specific postal code. Let me know if you need any further technical information or help placing your order. In either case I will be glad to assist!

Link to Closed Cooling Kit
http://tinyurl.com/3gnk7tt
 
Regards

Andy
 
Performance Product Technologies/IShopBoating
8002 West 6th Street
Stillwater, OK 74074
(405) 533-3812
Fax (775) 257-1769
[email protected]
www.perfprotech.com

Subject: Product Lead Question: FWC Kit – Engine Mounted, 3.0L “HIGH CAPACITY” (#5344)

robertson writes:
i have a 2004 searay 3.0L with raw water cooling and wish to convert. the mercruiser drawings show the heat exchanger is block mounted at oil pan level below the manifolds. Do you sell that option? i do not believe there is room enough to mount on the front of the engine
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