OK. Get the popcorn as this may end up being a long thread. Ifyou get annoyed by me asking multiple questions to responses, this thread maynot be for you. What we have here is a Merc 496 MAG (base) with a Bravo III duoprop outdrive. 1/2 system. I have done quite a bit of research on how towinterize this engine. 6 million different answers, techniques, procedures.Before devising a plan for winterizing, I need to understand the basics of whatI am actually "doing" when winterizing this thing. Attached is thepertinent information on the boat, along with a cooling diagram I believe to becorrect for my engine. Good starting point. The original diagram did not have akey to the numbers so I searched and came up with (I think), the correctnumber/description. Correct me if I am wrong.
No need to chime in on the things I already know:
· With 1/2 system, no need to drain the radiatorfluid (it was changed last year).
· It has the blue air pump system drain.
· It looks to have a manual 3 point drain system(2 for seawater pump/1 water drain going to heat exchanger).
As stated, you cannot apply a winterizing technique for thisengine unless you understand the basic operation of the cooling system. This iswhere I am at now. Below are questions that need answered before deciding on a"winterizing technique".
1. Starting at the red arrow, I follow the "lakewater" hollow arrows. Lake water comes infrom the drive to the inlet hose, through the seawater pump, out the outlethose around the back of the engine through the oil cooler, passes through thewater drain assembly. This is where I am getting stuck. It "looks"like it then passes through the heat exchanger to the port side then out theport exhaust manifold and exhausted overboard. Correct/Incorrect? The nextquestion (see red question mark on diagram) is the lake water looks to"turn around" in the heat exchanger and pass through the starboardexhaust manifold. Is this correct?
2. The crossover and circulating pump look to only circulateethylene glycol and both of these do not seem to circulate any lake water. Isthis correct?
3. What are we protecting when we "winterize" thisengine? It looks like we are avoiding freezing of the following components:
· Both exhaust manifolds
· Heat exchanger
· Oil Cooler
· Seawater Pump
Correct or incorrect?
4. Since the engine block is trulyclosed to any "lake water", and the radiator fluid has been changedand at the appropriate level, I am to assume there is no worries concerningcracking the engine block as there is no "lake water" going to theactual engine, only ethyl glycol. Correct?
No need to chime in on the things I already know:
· With 1/2 system, no need to drain the radiatorfluid (it was changed last year).
· It has the blue air pump system drain.
· It looks to have a manual 3 point drain system(2 for seawater pump/1 water drain going to heat exchanger).
As stated, you cannot apply a winterizing technique for thisengine unless you understand the basic operation of the cooling system. This iswhere I am at now. Below are questions that need answered before deciding on a"winterizing technique".
1. Starting at the red arrow, I follow the "lakewater" hollow arrows. Lake water comes infrom the drive to the inlet hose, through the seawater pump, out the outlethose around the back of the engine through the oil cooler, passes through thewater drain assembly. This is where I am getting stuck. It "looks"like it then passes through the heat exchanger to the port side then out theport exhaust manifold and exhausted overboard. Correct/Incorrect? The nextquestion (see red question mark on diagram) is the lake water looks to"turn around" in the heat exchanger and pass through the starboardexhaust manifold. Is this correct?
2. The crossover and circulating pump look to only circulateethylene glycol and both of these do not seem to circulate any lake water. Isthis correct?
3. What are we protecting when we "winterize" thisengine? It looks like we are avoiding freezing of the following components:
· Both exhaust manifolds
· Heat exchanger
· Oil Cooler
· Seawater Pump
Correct or incorrect?
4. Since the engine block is trulyclosed to any "lake water", and the radiator fluid has been changedand at the appropriate level, I am to assume there is no worries concerningcracking the engine block as there is no "lake water" going to theactual engine, only ethyl glycol. Correct?