Where to mount coolant expansion tank

[jamesbee19791]

I have a Bayliner 2452, partial closed cooling, Mercruiser 5.7, aplha1 gen 2. I don't think any of that info matters though. I bought this boat last year with no coolant expansion tank. I am about to install one. Does it matter if it's mounted above or below the heat exchanger? Thanks in advance!

 

[Fun Times]

From Mercruiser's engine inboard models installation manual regarding Closed Cooling Recovery Bottle (If Equipped)
1. Connect plastic tubing (from kit) to bayonet fitting on heat exchanger. Secure with tubing clamp provided.
a-Plastic Tubing b-Tubing Clamp
2. Select a mounting location for coolant recovery bottle and mounting bracket that meets all of the following:
a. Within limits of clear plastic tubing.
b. Level with or above, the heat exchanger fill neck.
c. Accessible for observing coolant level and filling.

+

Ideally, the bottle should be placed so that the cold coolant fill mark is roughly level with the height of the pressure cap.

https://www.passagemaker.com/channels/the-coolant-recovery-bottle-an-unsung-hero-of-the-engine-room

 

[jamesbee19791]

Thank you!!!