We have a Beta 60, new last year. It needs a header tank because the calorifier is higher than the engine
When installing, we kept the header tank from our untrusty Volvo, because it was installed and piped up. We quickly learned that the Volvo pressure cap is too wimpy for the Beta spec. We sealed the Volvo cap with epoxy, and the engine has run fine for 300 hours since then.
Thus our only pressure release is the Beta supplied original on top of the engine block.
No. As described, your system is not installed and working properly.
The header tank is required if the water-heater/calorifier is installed higher than the coolant cap on top of the engine.
In order for the engine coolant system to work properly, a vent is required at the highest point in the system to allow any air in the system to vent to the atmosphere.
When the header tank is installed as the highest point in the system, the vent cap on the header tank provides this vent.
It is important that the cap on the header tank be rated at 95 KPA / 13.75 PSI opening pressure.
The cap on the engine heat exchanger must have a HIGHER opening pressure. Approximately 99-100 KPA / 15- 16 PSI.
This difference in opening pressure is required to allow the system to vent and work properly. The cap on the engine heat exchanger MUST NOT open before the cap on the header tank opens.
If the cap on the engine opens before the header tank cap, you will not get the required venting of the system, and you will lose coolant from the system.
Your header tank installation may be related to your questions regarding engine operating temperature found else ware on the forum.
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Best regards,
Farron
Technical Sales and Service for Beta Marine, US Ltd. Minnesott Beach, NC PH: 252-249-2473 farron@betamarineusa.com
Thanks, you answer makes sense.
I think the air is under control, because the liquid in the expansion tank is about 2" below the top. However a better venting system as you suggest would make sense. We are in Norway just now, but plan to be in the UK soon. I will probably get a Beta tank there, if I can see a way it fit it into the space.