Engine Noise

[Cheechako]

One thing to keep in mind, the intake produces a lot of sound. A good breather of some sort may reduce noise a lot. Anyone ever put one of the high tech breathers systems like used on performance engines on a diesel?

[a64pilot]

Your speaking of course of a resonator, problem with those is they have to be specifically tuned for each engine application.
I do keep threatening to put my intake in my Lazarette, would be easy for me to do, and you right a LOT of engine noise is called intake Honk, more than many realize

[Cheechako]

Yeah, I first realized how noisy the intake is when running a diesel with the intake cover off once while working on it. Most diesel intakes are simple metal shields, no wonder the noise is so high.

[S/V Antares]

My Beta 38 is reasonably quiet. Much better than the Westerbeke I replaced.

The Beta comes with a sturdy metal sound dampening intake air filter combo. The replaceable air filter helps with the sound dampening.

I had a Perkins 4-108 with a course screen only and the intake noise was stupid loud.

I had a Peugeot car once with a very elaborate intake that greatly dampened the intake noise.

A little "sound down" material goes a long way.

[Calif.Ted]

My uninsulated Yanmar seems smoother and quieter than my uninsulated Perkins used to be, my friend has a newer version of the Yanmar I do but in his INSULATED Jeanneau you can barely hear the engine. They use a black egg crate like foam, I turn the radio off when I start the engine but on his boat you can still listen to music with the engine running.

[Lepke]

Half of my main deck cabin is over 2 Detroit Diesels. Sound proofing is the key. Lead sheeting makes the biggest difference as the first layer. I can hold normal conversations or watch tv above the engines at 1800 rpm.

[MarkSF]

Originally Posted by CampDavid

My question is general and broad in nature .

Which of the major diesel engines built in the last 15 or so years is the quietest?

I own a Perkins Prima 50 designed in the late 80's and produced for about 15 years 89 to 2001. In looking for a new to me boat I would like a quiet engine. I know quiet is relative and reliability and operating expenses are #1.

The new engine manufacturers seem to be Yanmar, Volvo , a few Westerbeeke and others.

I believe Yanmar is the engine of choice however how does it compare to the noise level.

Has anyone installed Sound down or something similar noise insulation in the engine compartment and if so did it make a noticeable improvement?

Thanks

Fletch

Sent from my SGH-I337M using Cruisers Sailing Forum mobile app

Yes, I used the Soundown material to soundproof the engine compartment on my Universal (Kubota) 5424, and it made a huge difference. I focused on noise in the cockpit, so put two layers of vinyl-loaded 1" material under the cockpit sole, one layer at the sides of the engine compartment, and two layers inside the doors to the compartment.

Most noise is now from the exhaust. Considering adding an extra in-line silencer.

My belief is that it is easier to make the cockpit quieter, than the rest of the boat interior, as inside the boat the noise travels through the hull, cabin sole, spaces, etc.

What exactly do you want to achieve? Silence is not possible. 10db quieter is possible.

In automotive applications the Prima was considered to be one of the noisiest engines ever made. I've been in an Austin Montego with the Prima and the racket was unbelievable. But the good news is you can certainly make it much better.

If the engine is running well, I certainly would try the soundproofing route as no matter how much you use, it'll be cheaper than a new engine!