Height in engine water systems.

[prv]

New boat has a calorifier hot water system, the first I've played with. The cylinder is mounted just above the engine, a Volvo D1-30, in the space between it and the cockpit sole.

The small engine coolant header tank is mounted in the cockpit locker, a rather awkward location where it's liable to get bashed, tangled up, and in the way. I'd like to move it into the engine bay, but I assume it's mounted where it is in order to place it above the cylinder, which it is by six inches or so.

Is this actually necessary, or can the cylinder be higher than the tank? I assume the water can't just "fall down" out of the tank coil and overflow, because it's sealed and like a siphon.

Pete

[vyv_cox]

Yes, I think you are correct. I was going to mount my calorifier quite high on the same basis but this is not going to work out now for other reasons. The original installation on my Sadler had a vertical calorifier with its top almost certainly higher than the cylinder head of the engine. I had to backfill the calorifier by taking off the upper hose but after that it worked perfectly.

Water cooled rear engined VW vans have the top of the radiator (in front) far higher than the engine. They can be tricky to fill thoroughly but fine after that. Some garages make up a tall pipe with a modified radiator cap on one end to make it easier to completely fill the system.