Request advice and comment on (my) skin tank system
Hello to all, and good to be on this forum!
We have a 57ft Ironworks narrowboat, build date documented as 1989, moored at Wenlock Basin Islington. As Ironworks do not exist anymore (as far as I know), I cannot consult them on my question, which concerns the design and operation of the skin tanks installed, as discussed below.
I have a horizontal skin tank either side of the engine bilge section, and these 2 form almost all the floor of the engine room, which is large. The coolant flow from the engine (heat exchanger) is routed vertically into one tank (via a hose connected to a +/- 30mm vertical stub welded at the front), and the other tank is similarly connected to the engine coolant pump for return. As the 2 tanks appear completely separated by the bilge section in-between them, I believe a +/- 30mm steel connection tube allows circulation from one tank to the other, and crosses between them at the aft end of the tanks. Estimating the surface area of each tank, and that they are +/- 2" deep (based on the depth of the engine bilge section), each tank may be up to 25 litres, which provides a cooling volume of 50 litres + engine volume + 30mm hose feeds; this seems very large to me.
I recently rebuilt my BMC 1800 engine after a long period without being able to run it. I reconnected the coolant hoses exactly as I had taken them off. When I test ran the engine, the skin tank on the RHS became warm (this is connected to the feed out from the heat exchanger) but the LHS stayed cold. I don't know if the connection pipe between the tanks warmed up or not, I should have checked. I am not sure if the tanks were circulating or not, with such a large potential volume I assume it can take a while, but no sign of warm water in the LHS anyway. However I also believe that if there is no circulation (maybe due to a plugged connecting pipe?), then neither skin tank will not get warm?
My queries are:
1. Would this be a typical skin tank design/layout, and typical of the volume I have estimated? Am I correct to assume a 2" skin tank depth? If only 1" depth, of course the volume is 1/2 of my estimation.
2. Would such tanks normally have internal baffles, and if so is there a correct flow direction for coolant in / out? Or is this not important?
3. Assuming correct direction of flow in my set up (from RHS to LHS), is there any way to check and maybe unblock the connection pipe other than cutting it open?
4. If the system is truly this large, is the engine coolant pump adequate to pull the coolant up a 30mm pipe (+/- 1m long) and circulate as required? Or is any additional pump recommended?
Appreciate any advice and comments on this!
Best Regards
Andy