Soundproofing the iron genny

[cwhiteot]

Has anyone replaced or added to the sound proofing around their engine?

I have a 30 hp Yanmar in my 90 Hunter Vision 32. I thought that the current sound proofing was fine but my wife had other ideas and asserted that a 'new boat' would not have this problem. To prove her wrong, we toured a new Beneteau 34. It was unbelievably quiet. I mentioned to the sales associate that I run my engine at between 2,200 and 2,400 RPM and would he mind speeding it up (since it was so obvously in idle). "It's running at 2,800 RPM." With egg on my face, I agreed to begin the process of replacing the soundproofing. Has anyone else tackled this problem? Was there an appreciable sound reduction with the newer sound insulation?

Thanks.

P.S. Engine is completely fine...

 

[Clark]

Not to throw too big of a curve here but consider also that the Bene engine was new; yours is 18 years old. I suspect that yours would have more noise anyway. With that said, improvement would be based on what is there now. If it is simply thin worn out foam, then replacement with the thicker stuff w/ heat sheild layer will help. Also, remember that the engine mountings (stringers & stuff) and surrounding structure will have an effect on noise. My direct experience has been with autos but a lot of the considerations are the same.

Good Luck

 

[Franklin]

Also keep in mind that 90% of the noise can come out of %10 of space, so look for little spaces where sound can sneak out.

I insultated my generator (PO installed it in a laz with only 1/2" of insulation around part of the laz) with 1" insulation all the way around and it made a hugh difference. However, a lot of sound did vibrate into the cabin still as I didn't mess with the motor mounts and they are very small.

After dealing with that, I can really apprecate the new generators that come with it's own soundproofing shield. So tempted to buy one.

 

[Don S/V ILLusion]

I have no experience with soundproofing the engine, however, be careful what you wish for in that if you effectively isolate the entire engine compartment, the unintended consequence of further restricting air flow for the intake as well as cooling can easily cause far worse problems.

 

[Benny]

I think you may be missing the point! Your wife imay be telling you that she is ready for a new boat. I know some guys that would jump at the opportunity by telling their wives, "honey you are absolutely right, no amount of insulation will quiet this engine down". Remember with women, you cannot be "right" and "happy" at the same time. It's an imposibility. Good luck.

 

[Steve Dion]

Other options that you may want to consider is vibration. If you have a two bladed prop think about a three. If you have a three bladed prop consider a Campbell. A friend of mine just replaced his 2 bladed with a 3 bladed Campbell and it made all the difference in the world. The prop works better and there is virtually no vibration at all.

 

[Joe Mullee]

Worked For Me

My soundproofing was the original foam and metal that I guess came with the boat when it was new (1983 Hunter 34). Besides that it was falling apart and I was continually mending it back together the cabin was very loud. Two winters ago I replaced all of it with new product from Sailors Solutions http://www.sailorssolutions.com/index.asp?page=ProductDetails&Item=SPM24

It's made a BIG difference in the noise level. The other answers all make sense as well but this may be the least expensive thing to try first.