5.0L Mercruiser Engine Question

[mounty]

My engine serial number is 0w360991 which i believe is the 305 CU IN GM V8 with a Bravo III outdrive. In the manual i see reference to a single point drain, 3 point drain and online I see a 7 point drain referenced. I'm not at the boat and wondered if there was some way to find out what my engine has without looking at it. I want to change the thermostat but not sure which configuration I have.

Thanks in advance

 

[alldodge]

If we assume you do not have closed cooling, then you would still need to look or remember what it looked like.

The single and 3 point has s water distribution housing on the port side front down low. This is where the water is drained out

https://www.mercruiserparts.com/bam/subassembly/31750/11681/250

 

[mounty]

it is a closed cooling system. what's the difference between a one point and three point cooling system?

 

[alldodge]

The 3 point is with a Bravo drive and it has 2 drains for the seawater pump

The 1 point is with an Alpha drive

You will have the thermostat housing in the lower pic
https://www.mercruiserparts.com/bam/subassembly/31750/11681/220

 

[QBhoy]

Also to be suggested that it’s a good idea not to trust the function of such a system entirely. Good idea to verify all is doing what it should...when it comes time to winterise and drain.