Russell Newbery DM2 cooling

[starman]

My DM2 is plumbed with the header/expansion tank in the return line from the skin tank (going into the top of the header then out at the base) rather than what appears to be the usual method of putting it between the flow from engine thermostat housing to skin tank. Apart from this it seems to be a pretty much 'standard' system with the calorifier in the by-pass loop and an AAV where this joins the thermostat housing.

The engine hasn't had any serious running with this set-up so my concern is will it work okay and will it be prone to airlocks? I have noticed there is no air bleed close to the skin tank which I wonder could be another source of air locking.

[Tony Brooks]

Depends where about on the skin tank the outlet is and how the pipe runs. If the outlet is at the bottom of the tank (typical position) and there is no air bleed on the skin tank then I think the skin tank will airlock and the airlock will be difficult to get rid of. If the outlet is at the top of the ski tank and the pipe runs uphill with no bows to the header tank then it should self bleed.

 

Think that any air of gas will try and work its way upwards. if upwards ends up in a vented area then the air or ga scan escape. If it ends up in a non-vented area it won't vent so will airlock.

[Jrtm]

Best way to remove air lock is to

Have input to engine about 2 inches up from bottom of tank (stops you picking up any partials in the tank)

Have you return to the tank (from engine) at the top of the tank.

have a pipe off the tank and run up and above engine with a small open tank or just a breather on the top of the pipe. Rn and nationals can't run a pressure system so as long as the small fill pipe is above engine you can't get water to escape.

 

If you have 2 tanks e.g one each side or something sim have a join pipe at top and bottom of the tanks