towpathrider Posted November 20, 2017 Report Share Posted November 20, 2017 I currently have two skin tanks, one connected to a beta 38, which provides propulsion and the other connected to a beta 35, which runs a genset. The engines are never used simultaneously. The beta 38 skin tank is undersized, and while this hasn't been an issue yet on canals I'd like to connect the two tanks to allow for more cooling capacity if on rivers/tidal. Would a simple connecting hose/pipe between the two tanks be sufficient enough to allow coolant to flow between the tanks, if it is of sufficient bore i.e. 28mm? Link to comment Share on other sites More sharing options...
Sea Dog Posted November 20, 2017 Report Share Posted November 20, 2017 (edited) Sounds feasible, but here's another suggestion to ponder: assuming your 38 also supplies your calorifier, tap into that circuit and add a small towel rail in the bathroom. Although my skin tank is fine on my Beta 43, I've done this downstream of my calorifier, using full bore valves to feed it so it can be isolated and with a full bore valve as a bypass. It works beautifully with all valves wide open, but I would be able to adjust if it was stealing too much engine heat. There's no engine temp issue and the calorifier heats up just fine. As well as dumping a bit of extra heat for you, you'd have nice warm towels and/or a warmer bathroom which isn't an issue even in summer. Mine's 400 x 300 iirc, but a myriad of sizes are available if you need to lose more heat, although it sounds like you are only adding a bit for belt and braces. Just another option to consider. Additionally, whilst adding the second skin tank would bring the desired extra cooling for the 38 (which may be too much) it would also add lots more to presumably the quite happy 35 - which probably would then be running too cool. Edited November 20, 2017 by Sea Dog 35 cool running Link to comment Share on other sites More sharing options...
ditchcrawler Posted November 20, 2017 Report Share Posted November 20, 2017 Are you proposing to keep the two engines connected to the 2 tanks as well as commoning the tanks together? I have never tried it but I think you would need the 2 tanks in series with the main engine to work Link to comment Share on other sites More sharing options...
system 4-50 Posted November 20, 2017 Report Share Posted November 20, 2017 1 hour ago, Sea Dog said: Sounds feasible, but here's another suggestion to ponder: assuming your 38 also supplies your calorifier, tap into that circuit and add a small towel rail in the bathroom. Although my skin tank is fine on my Beta 43, I've done this downstream of my calorifier, using full bore valves to feed it so it can be isolated and with a full bore valve as a bypass. It works beautifully with all valves wide open, but I would be able to adjust if it was stealing too much engine heat. There's no engine temp issue and the calorifier heats up just fine. As well as dumping a bit of extra heat for you, you'd have nice warm towels and/or a warmer bathroom which isn't an issue even in summer. Mine's 400 x 300 iirc, but a myriad of sizes are available if you need to lose more heat, although it sounds like you are only adding a bit for belt and braces. Just another option to consider. Additionally, whilst adding the second skin tank would bring the desired extra cooling for the 38 (which may be too much) it would also add lots more to presumably the quite happy 35 - which probably would then be running too cool. How can a thermostatted engine run too cool? Link to comment Share on other sites More sharing options...
David Mack Posted November 20, 2017 Report Share Posted November 20, 2017 Connect the second tank so the hot water from the engine goes to the top of the first tank, out of the bottom, then into the top of the second tank, then from the bottom of that back to the engine. Link to comment Share on other sites More sharing options...
BEngo Posted November 20, 2017 Report Share Posted November 20, 2017 Follow the flow pipe from the main engine to (hopefully) the top of its tank. Connect the bottom of that tank to the top of the second one ( where the other engine should be feeding in) and then the bottom of the second tank back to the main engine as well as to the other engine. Don't worry about over cooling the main engine- the thermostat will take care of that, assuming one is fitted. Caveats. Make sure you can fully vent both skin tanks in the new set-up. You may need to install swing non-return valves or full-flow lever valves in both engines' return lines to ensure that the water goes where it is wanted. The main engine circulation pump may or may not be happy with the extra flow restrictions. It will probably be OK provided the inter-tank pipe is a decent size (bigger is better) and all the bends are reasonably gentle. Both engines will have be part of the same cooling circuit, so the lowest header tank is likely to overflow. You can get sealing caps if it has the standard car radiator type cap. Top up via the highest tank Flush well and renew the antifreeze completely unless you are sure both engines are on the same type of antifreeze. N Link to comment Share on other sites More sharing options...
Sea Dog Posted November 20, 2017 Report Share Posted November 20, 2017 28 minutes ago, system 4-50 said: How can a thermostatted engine run too cool? No, you're right. I wandered off my thought train on the effects of adding a rad in the calorifier circuit and mistakenly extended the effects onto the 35! I'd still be a bit reluctant to break into the perfectly happy 35 cooling circuit because of an unproven worry that the 38 cooling might need beefing up. Link to comment Share on other sites More sharing options...
towpathrider Posted November 20, 2017 Author Report Share Posted November 20, 2017 26 minutes ago, BEngo said: Caveats. Make sure you can fully vent both skin tanks Thanks, just checking what you mean by fully vented? Do you mean in order to bleed them when re-filling? (both tanks have bleed points) otherwise, the coolant is vented at the engines' header tanks. Link to comment Share on other sites More sharing options...
BEngo Posted November 20, 2017 Report Share Posted November 20, 2017 1 hour ago, towpathrider said: Thanks, just checking what you mean by fully vented? Do you mean in order to bleed them when re-filling? (both tanks have bleed points) otherwise, the coolant is vented at the engines' header tanks. Yes. I meant get all the air out. The existing vents/bleed points should be fine. N Link to comment Share on other sites More sharing options...
alan_fincher Posted November 20, 2017 Report Share Posted November 20, 2017 (edited) 5 hours ago, Sea Dog said: Additionally, whilst adding the second skin tank would bring the desired extra cooling for the 38 (which may be too much) it would also add lots more to presumably the quite happy 35 - which probably would then be running too cool. Sorry, but that makes no sense. If the engine has a correctly working thermostat, it is simply impossible to overcool it. With a thermostat you simply can't have a "too big" skin tank. EDIT: Sorry should have read on - I see several others made the same point! Edited November 20, 2017 by alan_fincher Link to comment Share on other sites More sharing options...
Sea Dog Posted November 20, 2017 Report Share Posted November 20, 2017 5 hours ago, alan_fincher said: EDIT: Sorry should have read on - I see several others made the same point! Well, 4-50 did, but I back-pedalled pretty quick and explained myself before I got flamed too badly! That bit was rubbish though, so I'll also take your shot on the chin. Link to comment Share on other sites More sharing options...
Featured Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now