air cleaner or noise reduction for YSB8

[Halifax Sailor]

another season in the books and nothing broke! YAAAAAAAAAAAA!! so on to winter projects, last couple of seasons, when running engine, not too often, but when i do am wondering if anyone has ever fitted an air cleaner setup to a YSB 8? at present just has an open J shape intake that curls up over the engine, there is room for an intake hose i guess if fitted but where should i run it and what size type filter? have read many discussions that air cleaner/filter will quiet i down as a lot of noise is just the intake. have worked with diesels on the farm and they always had large canister type filters, much too large for this engine, have looked at setups online for YSB 12's and they have air filters, of course can't find where or if they are available. Had one guy suggest a competitive style car air filter setup but one I priced was over $600.

and on another thought, i am thinking on placing some noise limiting structure or foam/bubble wrap/some type of egg crate type stuff to the surrounding area and the back of the stairs/ladder. there is some noise limited stuff with a lead core out there but not wanting to add much weight to the boat (only 9000 lbs so additional 3-400 would be a big deal) have decided against this stuff. any ideas?

[DeepFrz]

Check out Soundown. They may have the sound shield stuff you are looking for.

Walker Air Sep may have filters.

[tkeithlu]

If you are going the route of sealing in the sound, you have to cover every single surface and seal the connections. One tiny crack, and the noise just seems to spout out of it. You also have to deal with the possibility that nearby structures such as fuel tank sides may have resonant frequencies within your engine RPM range. It may be cheaper and less trouble to go the air inlet route.

[Pauls]

Air filter size is not important, so long as it is big enough. In other words too large is OK. If the filter canister intake is equal to or larger than your engine intake port it will be OK.

Filters by themselves cut down intake sound a bit but most of the muffling comes from the filter housing. The larger the internal volume of the housing is relative to the size of the housing intake the quieter it will be.

You don't need to spend a lot on this if you can find a used housing that will fit your set up. And you can almost eliminate intake noise by routing the intake air thru a separate silencer before it enters the air filter housing.

[Sailmonkey]

https://www.mrostop.com/g057513-dona...FUo6gQod6RML1A

Here ya go. 2" connection....


Sent from my iPhone using Cruisers Sailing Forum

[Djarraluda]

Engineers love acoustics questions, it is the time we get to prove that 2 + 2 really does equal 5.
Leaving that fun bit aside, we have sound as a spectrum, lets just say High pitched, down to Low pitched. I emphasise this lot is extensively simplified and generalised here but, before tackling any project, think what you want to take-out - why....
High pitched - change the direction
Low pitched - needs density

So the lead sheet in foam (or even barium in high tech products) are tackling a generalised, broad spectrum. The dense sheet in the middle is absolutely critical to the low frequency noise. The closing of gaps is critical to all bits of the spectrum. The foam and bubbles perhaps more on the high frequency.

1st, what is the source. Air inlet is one, exhaust is one, but so is the general vibration from the engine and most critically, vibration from everything being shaken by the engine.

Yes, attenuate the air inlet but all you need is a large tube lined with the foam. Air filters work but a foam tube also works.

1st approach in my view is to check engine mounts, flexible couplings etc and eliminate transmission of vibration. Next, close up all direct air paths to the cabin and cockpit. Note the difficulty here, the engine must still breath and the compartment must ventilate.

With mine (I have a YSE8), I have lined all panels, closed gaps to the cabin and maintain the anti-vibration mounts and couplings. More than that, you need to remove the engine to start with.

Be practical in what you can achieve.
Roger