There's a company now offering aftermarket closed loop cooling kits for MerCruiser engines, in both raw water exhaust, and closed loop exhaust (where the manifolds are cooled by antifreeze). They work very well. I installed the closed loop kit for both engine and manifolds on my 2006 4.3L.
Great information! Any chance you have a video on winterizing it? Just bought a boat. It has this set up. However. It sucks up water from the bravo3 and also through the hull with a ball valve.
No video on winterizing but if you are running antifreeze on the closed side half is already done. Just follow the pipe coming off the hull and drain all low points. The exhaust manifolds will need draining and the raw water side of the heat exchanger. If its fuel injected the fuel cooler as well. EDIT: let me clarify low points. I’m not talking about just the obvious lowest piping in the bilge. I’m talking about traps where water is trapped in any low points below two higher points. In the video the pipes leaving the heat exchanger going to the bottom of the exhaust manifolds are low traps even though the raw water pipe at the fuel cooler is technically lower. So if we use the engine in the video as an example, you’ll need to drain the raw water pump itself and the hose leaving it going to the steering cooler, you’ll need to drain the fuel cooler, and then drain the hose under both exhaust manifolds. To drain a hose Mercruiser usually installs the blue twist plugs to make it easier but not always. As long as you have good antifreeze the block and intake doesn’t need draining.
If there are no leaks the system expansion tank should do the job of allowing the water to expand and contract between run cycles. So after initial fill and expansion you don’t need the bottle. But in the real world the bottle makes up for any leaks over time.
Does the raw water side when leving the HX to the exhaust manifolds have the same hose exit or seperate? I need to barnicle bust and trying to figure the return to bucket location. TY
At the 3:30 mark I point out the port exhaust hose leaving heat exchanger and at 3:40 mark I point out the starboard exhaust hose leaving heat exchanger.
You just answered a big question i have about the cooling system diagram with the mericruiser 5.7. Ive got some questions before I purchase some of your products you have for the EST ignition mod, how can i email you directly?
No you still have to drain the exhaust manifolds as they are low points in the raw water side. Any low points in raw water side still have to be drained.
There's a company now offering aftermarket closed loop cooling kits for MerCruiser engines, in both raw water exhaust, and closed loop exhaust (where the manifolds are cooled by antifreeze). They work very well. I installed the closed loop kit for both engine and manifolds on my 2006 4.3L.
They are very expensive wouldn’t it be a lot cheaper to just maintain it properly? On the other hand, lack of winterizing keeps me in business.
Great information! Any chance you have a video on winterizing it? Just bought a boat. It has this set up. However. It sucks up water from the bravo3 and also through the hull with a ball valve.
No video on winterizing but if you are running antifreeze on the closed side half is already done. Just follow the pipe coming off the hull and drain all low points. The exhaust manifolds will need draining and the raw water side of the heat exchanger. If its fuel injected the fuel cooler as well.
EDIT: let me clarify low points. I’m not talking about just the obvious lowest piping in the bilge. I’m talking about traps where water is trapped in any low points below two higher points. In the video the pipes leaving the heat exchanger going to the bottom of the exhaust manifolds are low traps even though the raw water pipe at the fuel cooler is technically lower. So if we use the engine in the video as an example, you’ll need to drain the raw water pump itself and the hose leaving it going to the steering cooler, you’ll need to drain the fuel cooler, and then drain the hose under both exhaust manifolds. To drain a hose Mercruiser usually installs the blue twist plugs to make it easier but not always. As long as you have good antifreeze the block and intake doesn’t need draining.
@@moccasinmarine i would also love a video on winterising it!
best video for closed cooling. i had ZERO idea. explained VERY hose. buenow
Glad it helped
Does this require an overflow bottle? There appears to be an expansion outlet by the cap.
If there are no leaks the system expansion tank should do the job of allowing the water to expand and contract between run cycles. So after initial fill and expansion you don’t need the bottle. But in the real world the bottle makes up for any leaks over time.
Is there a system for the newer merc 6.2 i believe from 18 to present
Does the raw water side when leving the HX to the exhaust manifolds have the same hose exit or seperate? I need to barnicle bust and trying to figure the return to bucket location. TY
At the 3:30 mark I point out the port exhaust hose leaving heat exchanger and at 3:40 mark I point out the starboard exhaust hose leaving heat exchanger.
You just answered a big question i have about the cooling system diagram with the mericruiser 5.7. Ive got some questions before I purchase some of your products you have for the EST ignition mod, how can i email you directly?
Moccasin.marine.llc@gmail.com or text 706-358-3175 and I will return your text when free
❤Merci Merci ❤
How can i flush this system with freshwater after use in salt water? And how can i add antifreeze to the engine water
Watch the video and read the comments. Your questions are already answered.
So, no need for winterizing the boat at all, correct?
No you still have to drain the exhaust manifolds as they are low points in the raw water side. Any low points in raw water side still have to be drained.