
A wiser man than I was once asked what had been the greatest single advance in small craft safety in the last seventy years. His reply was simple and to the point:
The reliable diesel engine.
To which I can only say “Amen”.
So within our refit project plan and budget, the engine fits right at the top of the list. That said, what’s the best and most cost-effective way to guarantee that we fulfill that key requirement ‘reliable’?
An Unreliable Engine Is No Fun

Let’s start from the position that there are few things more depressing in cruising, whatever your horizons, than having to live with an unreliable engine. And, worse still, when you’re a long way from home or help, and the chances of rebuilding or re-engining in, say, Labrador, are slim or none, a dodgy engine could become a serious handicap.
Bear in mind, too, that cost is only part of the equation here, peace of mind is of equal value—that is, being confident that the damn thing will start at the crucial moment.
Rebuild or Re-Power?
Let’s imagine that the boat we have identified as a possible purchase dates from the 80’s, is around 40 feet long, and still has the original engine. It’s working, but has quite a number of hours on it (say 5000), which might certainly be enough to justify a rebuild if it hasn’t had one already. Would we be better to bite the bullet and replace it with a new engine off the shelf, or rebuild it?