Trojan Boat Forum

Hi, I have seen that some owners have repowered with diesels but those threads are all quite old. I have twin 5.7L Mercruisers and I want to find some diesels that will drop in with the least amount of modifications. I am not looking for speed, just the reliability of the engines. Thanks!

Yanmars would likely be the easiest. But none would be simple "bolt ln" There is a thread on a 32 repower, while it is a few years old most the info would still apply. Honestly, it would be far cheaper to find a boat that's been repowered than to do it. Even used marine diesel can run 15k-20k each.

I moved this to the Trojan Boat forum where it will be seen. You say your not looking for speed. Did you what to maintain you current speed capability or plan on running below planing speeds say 7-8 knots max?

HI, I would be happy if I could get up to 14 knots. Thanks

suggest you first determine the most efficient planing speed for your hull with a diesel - not easily determined.

On my 10 meter the most efficient on plane speed with her 454 gas burners after prop tuning and other improvements was approx 15 knots.

This was verified with a floscan digital tach/sync and GPS

After the YANMAR 6LP repower the most efficient on plane speed increased to 19-22 kts (flat data)

Fuel economy nearly doubled.

We could go farther and faster in a day on the water, opening up all kinds of new adventure possibilities.

FOr example, a run to Key West became an easy one day trip - depart at 6 AM, arrive at 2 PM

WIth the gas engines that run would be a 2 day run with a fuel stop on the way.

Given todays technology, the choice is simple

outboard gas engines or diesel inboards.

From the standpoint of safety, reliability, maintenance and efficiency there is no other choice.

BEST !

RWS

Thank you for the reply and all the info...much appreciated.