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Engine choice

Anticipating a new build 57' to 60', I am considering fitting a 50hp engine to allow for extra grunt and would ask ... What do other owners consider to be the most reliable of the currently available modern engines?
Thanks in advance.

Asked by: John  | 6.43am, Friday 15 November

WW says:

Unless you are planning to do a lot of your cruising on rivers, I would be wary of fitting too large an engine in a narrowboat. Diesel engines operate most efficiently when they are working fairly hard. If they are running at barely more than tick-over for long periods, they never reach their proper temperature which can result in sludging, glazing of the bores and a smoky exhaust. Running more slowly could also mean that the alternator is not putting enough charge into the batteries. You could fit a finer pitch propeller so that you could increase the speed of the engine but this would just waste fuel. For the size of boat you mention, a 35hp to 45hp engine should be about right.
If, by 'grunt', you mean more torque, you could consider an engine like the Beta JD tug engine but this would generally require a larger propeller and, consequently, a deeper draught on the boat. This may mean that finding a mooring is not as easy as with a 1ft 9in to 2ft draught. The JD3 is better suited to heavier, working boat type craft.
I cannot really comment on which engines are most reliable but other readers may like to offer their experiences.

Graham Booth  | 10.22AM, Friday 15 November

Also if the engine is only running at tickover on canals, because it is too big- then the alternator output may be quite low and so battery charging is not as effective.
Also many larger engines are fitted with insufficient skin tank cooling surface area (at least 1sq ft per 4hp and preferably more) and insufficient ventilation, not just for combustion air, but allowing hot air out- again 1sq in per hp is the absolute minimum. All engines need to follow this advice- otherwise performance, especially on rivers, is compromised.

Mark Langley  | 4.03PM, Friday 15 November

Readers say:

Thank for the prompt response Graham. You raise an interesting and valid point which I had not considered eg working temperature and poss' glazing.
It'll be interesting to see what thoughts others have to offer.

John  | 11.50AM, Friday 15 November

Thanks Mark,
Even allowing for Solar Panel input your charging point is highly valid.
Given the points you both outline, it would appear that a Beta 43 rather than a 50 would be the better option.

John  | 11.38PM, Friday 15 November

i have a59 ft narrowboat and have a 35hp and have cruesed all over tidal ecti have never had to use more then 50%of my power if getting a new boat 60ft i would still fit a35hp and also bigger may use more fuel

christopher smith  | 4.07PM, Saturday 14 December

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