Upgraded Volvo D2-50 instead 2030, found no expansion tank for cooling water

[CaptainRivet]

Hi all,

I bought a FP Lavezzi with new upgraded engines from the 2030 to the Volvo D2-50 and 130S saildrive. All is new from exhaust till seacock as nothing fitted and engine/saildrive swap was done by Volvo Spain directly.
I discovered that both engines don‘t have Expansion tank for the cooling water, the pipe just goes straight down in the bilge while my buddy boat a dufour 44 has a D2-55 (same engine) that has an expension tank.

Correct, can you do this or do I need to add expension tanks?
Thank you

[Hhew]

I have a D2-55 in my Bene 42 with no expansion tank. The vent hose routes to the bilge, but frankly under normal operation it does not vent any coolant.

[DougR]

For the average D2-50/D2-55 installation there is no need for a remote expansion tank. There is adequate volume in the standard expansion tank to handle coolant expansion without overflow.

There are two instances, however, where a remote expansion tank may become necessary:
- if the engine coolant is plumbed to a house hot water tank and the hot water tank is mounted above the engine, then a remote tank is necessary to allow the system to be bled of air pockets. In no case should the remote tank be mounted higher than 1.2 meters or 4’ above the top of the standard expansion tank.
- If the volume of the external circuit to the hot water heater or cabin heater exceeds about 1.6 liters then a remote expansion tank is necessary to handle the added volume.

I have a D2-55 with a house hot water tank mounted about 5’ away from the engine and have never seen any coolant in the bilge, and I do not have a remote expansion tank.

[CaptainRivet]

Originally Posted by DougR

For the average D2-50/D2-55 installation there is no need for a remote expansion tank. There is adequate volume in the standard expansion tank to handle coolant expansion without overflow.

There are two instances, however, where a remote expansion tank may become necessary:
- if the engine coolant is plumbed to a house hot water tank and the hot water tank is mounted above the engine, then a remote tank is necessary to allow the system to be bled of air pockets. In no case should the remote tank be mounted higher than 1.2 meters or 4’ above the top of the standard expansion tank.
- If the volume of the external circuit to the hot water heater or cabin heater exceeds about 1.6 liters then a remote expansion tank is necessary to handle the added volume.

I have a D2-55 with a house hot water tank mounted about 5’ away from the engine and have never seen any coolant in the bilge, and I do not have a remote expansion tank.

Thank you for the detailed explanation.
Ok non needed in my case.
Have no min/Max marking, what’s a good filling…the Standard 2 fingers below the top?

[DougR]

From the owners manual....