making my engine more efficient and quieter

[nickfabbri]

I have a volvo md5b powering a jaguar 25 . It is the weakest and noisiest engine in the marina.The questions I have are; Will i benefit from upgrading the sound proofing? Also would changing to a three bladed prop be of any real benefit, or would the cost be ridiculous for such a small engine? Finally if this engine eventually packs in, can I replace it with a bigger one? Thanks

 

[Topcat47]

A 1GM10 would be more than adequate and a lot quieter. If you could stand the added cost and complexity of FW cooling, the Beta12 would be even beta (sorry for the pun) as it's a twin.

Unless you're a fan of old engines, I'd not spend a penny more on the Volvo than I couldn't avoid. spares are expensive and not universally available. Check your volvo agent to see what's no longer listed.................

 

[Avocet]

It's pretty hard to retrospectively sound proof an engine compartment that wasn't designed with sound deadening in mind. I got quite good improvements on our nasty single cylinder diesel by fitting a flexible propshaft coupling and some hydraulic Vetus engine mounts. I was amazed how much of the noise was structure-borne. Plus, if you do this and are still not happy at least you could possibly use those bits on your next engine!

 

[bumblefish]

Or a new Bukh DV7 ME

 

[nickfabbri]

sounds like adding hydraulic engine mounts is difficult and expensive.

 

[Peegee]

Nick. Being a close neighbour! Have you looked into changing to a waterlock/silencer in the exhaust system of CM.

 

[nickfabbri]

Cheers peter, I will look into it. Although as new as we are to sailing i have no idea what that means.

 

[Avocet]

Our engine lent itself to it very well. They just fitted as direct replacements for the old rubber ones that were there. We did have a rasonable amount of room round the old ones though but you can always look at the drawings (I think they have them on the Vetus site) and see what the size difference is. We supported the engine on a piece of wood across the hatch suspended from a small engine hoist and changed them one at a time. Re-aligning the gearbox coupling with the propshaft wasn't quite so critical because we also fitted the flexible coupling. These ARE pretty expensive though. I had access to good engineering facilities at the time so I made my own but I do accept that it would be a fair bit more than some sheets of sound deadening. That said, we als odid that to our boat and they made less difference than the mounts & coupling. In fact, I've since ripped out some of the sheets because they often got waterlogged.