Forums » Ask a Question

Use this forum to post your questions to our experts – you need to be logged on to do it (you can register here ), then scroll down to the bottom of this page and click the blue Post Thread words

If you can help answer the question, feel free to post a reply – you need to be logged on to do it (you can register here ), then hit the reply button on the thread.


To go back to the experts page click here>>


Posted: Fri Nov 08, 2013 3:55pm

Post Subject: Cooling on the river

Hi, I have a 10year old ex hire boat and whenever I do continuous river work at over 1400rpm and the calofier is up to temp, the engine starts to overheat. I have replaced thermostat, flushed system, bled system etc to no avail. I only get a 2degree drop between in and out of the keel tank when flowing(good flow). The tank is 7.2 sq ft and I have an isuzu 42 which revs to 2200 max. Why am I not getting the cooling out of the tank. Are lack of baffles (dont know if there are any) likely to make a big difference and also it has been blackened with vinyl based product at least 10 times so would this thick coating prevent heat transfer through the hull?


Posted: Fri Nov 08, 2013 6:55pm

Post Subject: Cooling on the river

Beta give the required single surface skin tank area as 1 sq ft per 4 hp while my calculations give a slightly larger area but are close enough to the Beta figure. Now assuming the 42 in the engine designation is 42 bhp that indicates that you require a skin tank are of about 10.5 sq feet so straight away we cans see the skin tank is too small for that engine when running at full power. That figure assume baffles in the tank but I have no idea if your tank is baffled or not. A build up of blacking will insulate the tank so I always recommend that the blacking on the tank part of the hull is removed at every blacking and then given just two or three coats. Undersized skin tanks are very common on canal craft. There are a number of ways of overcoming it like making a new tank on the outside of the swim, putting another tank on the other side, putting cooler pipes through the hull on the other swim, and making another skin tank between the engine beds. Personally I would want another tank on the outside of the swim but it is best to discuss your options with whoever is doing the job. Tony Brooks

Most Read

Newsletter Sign Up

Canal Boat monthly newsletter
Sign up to receive our regular email newsletter

Our Privacy Policy

Like us on Facebook

Follow us on Twitter

Cache: Disabled for this object  Total Queries: 43.  Total Objects: 162.  Total Unserialized: 3. Total Runtime: 0.25 seconds.