'63 Lark V What is the purpose of this groove?

[Grain Boat]

I'm in the process of replacing seals on my lower unit but I'm dogged by the purpose of this groove. Any takers?

 

[Chinewalker]

Re: '63 Lark V What is the purpose of this groove?

It's a drain as that portion of the housing is open to the water. You'll note the spaghetti seal ends before that area. Allows water out so it doesn't freeze and crack the housing...
- Scott