Engine racket at the helm

[Sunsetrider]

I hesitate to mention this since I have never heard (seen, read) anyone else bring it up. Is it the fabled elephant in the room? As the helmsman I never get the chance to escape to the bow area where it is breezy and quiet - I am subjected to the ear-pounding diesel clatter non-stop and it is frankly getting old. This year I will be doing a lot of solo boating, so I see no respite in sight. I find myself daydreaming about ways to silence the mayhem. I can think of two:
- regular foam ear plugs, of the type I used to wear to tame the wind roar while motorcycling, and
- my fancy noise-cancelling headphones, used mainly on airplane trips. I don't know if they will affect the low-frequency diesel noise as effectively as they handle the steady thrum of the jet engines.

What do others do? Does everyone simply adapt? The engine box is already lined with noise-absorbing foam, but that is not enough for me.

[WillieC]

Ah, the beloved Volvo Penta. I sometimes sit on the edge of the hatch above and drive with my feet, but it is tricky keeping an eye on the gauges, thus I will be adding audible alarms. The Starfleet Commander does a lot of driving, since I keep reminding her it is her boat, I am just the cabana boy/support staff. She is a very good driver, and docker. Better than I .

Picking the sweet rev range is critical for my hearing. The MD3B was much quieter at 1600-1650 than say 1800. The yet to be installed MD17C is just as serene.

Pay close attention to any gaps in the engine cover mating surfaces. Also the gaping wound where the cables run through to the battery compartment. The first year we had the boat, the misaligned shaft and broken engine mounts pretty much drowned out the thrum of the engine, but I wouldn't recommend that plan of attack.

Another thought, I think there was a thread on using sound deadening blankets not long ago. How about a heavy blanket, or carpet remnant over the box? Be clever about incorporating it into the decor ala Lebowski. I installed workshop rubber-like floor mats from Harbor Freight over the box and battery compartment, since mine are the same level. I think yours is lowered if I recall correctly. That could account for additional racket if so. Some noise crawls up along the hull and comes through where the Espar heater is, again, that open path of travel to deal with.

Otherwise, it is an A25 and the low revving engine brings its resonant frequency with it. The newer, higher revving engines are smoother and therefore potentially quieter, though I have only been on two others. (The first one shamed me into fixing the shaft issues. And it was a 4 cylinder VP, 2030 I think. They have their issues too.)

I hope you can find your way with it. Do you have an autopilot? I will pursue that if I can catch my breath. I am thinking old school, I don't even know the name. The BC folks pretty much all have them and I hear they can be found in junk sales up there, cheap. I am looking.

[Northern Spy]

All the above suggestions are great and really cut the noise in half on my A25. This year we installed a bimini top so we could take the canvas off the helm without getting burned to a crisp from the sun. it also makes a big difference in sound level. Other things I intend to try this summer are insulating the engine box using more of the premium material from Defender (1 kit was not enough). I want to add an air filter and box from a compact tractor to silence the intake noise and I would like to install some sound deadening or carpet to the inside of the wheelhouse below the windows.

[DesertAlbin736]

Hmmmmm.... I've never had that problem with our boat, she runs fairly quiet & vibration free. Then again our boat was re-powered with a 24HP Yanmar 3GM30F & equipped with AquaDrive CV joint & thrust bearing unit, so in addition to the stock sound deadening foam lining of the engine box I don't know what else to suggest. I know we can easily hold a conversation while motoring along at 2,350 RPM & 6.5 knots cruising speed. However, that said at certain lower RPMs, between around 1,200 to 1,500 or so we get a bit of a harmonic 'whine' noise that goes away at slower or faster RPMs outside of that window, but never obnoxiously loud or clattering.

[WillieC]

"though I have only been on two others." Desert Albin's is one of those quieter ones we have been on. Hira's Shatoosh, after she sold it, is the other, with the VP 2030. Myself, I can't wait to get the refreshed MD17C on board. I'll deal with the racket, one way or another.

[Beta Don]

It's probably not fair to compare any of the little Yanmars to the 45 year old blocks if iron that came in these old boats. They're all much lighter, smoother, more fuel efficient and they came with really flexible motor mounts which don't transmit nearly as much NVH to the hull

Don

[WillieC]

I was trying to say as gently as I could, it is what it is. So for a cool 15 large you could quiet it down. I'll live with mine, for now.

[Sunsetrider]

I'll just delay getting those hearing aids for a few more years.

[sail149]

As an out of the box idea you can get remote wireless stering control for auto helms allowing you to sit on the foredeck to steer.
Safety issues are up to you but could be figured out.
Check out this video at about 4.00
https://youtu.be/DypG9Ipx47A
Cheers Warren

[Sunsetrider]

I am now tackling this issue head on by re-insulating the engine box with a product from Soundown. The first pic shows the difference between the old and new foam insulation. The second shows the old foam laid atop the 72 x 54 inch Soundown sheet. A single sheet is more than sufficient for the A25 Box.

[DesertAlbin736]

Stephen, I sure hope the upgraded engine box insulation helps. Since the origins of this thread date back to a year ago, my reply of April 27, 2017 was before we got to meet up and were treated to a ride on your boat around a small bit of the Thousand Islands. That was one of the major highlights of our big East coast RV road trip last year, and we still talk about it & had such a lovely time, not just the boat ride but all your hospitality (butter tart contest!) & your lovely home on Sharbot Lake. Oh, did I forget to mention butter tarts?

That said, we got to experience the engine noise you're talking about first hand. I will also say just recently we met Joyce, the new owner of Shatoosh when she brought her boat up to our home lake here in the Phoenix area a couple weeks ago. Unfortunately it was her first time trying out Shatoosh since taking ownership & bringing it down from Sacramento (she had changed the name back to "Shatoosh" from "Hobbit") and she didn't get any farther than the ramp dock since the raw water pump wasn't pumping & soon overheated after idling for awhile. She couldn't find any spare impellers on board (later she did find one after taking her boat back to her home in Green Valley, AZ), so we had to pull the boat back out & she went for a ride on our boat & had a nice lunch together with my wife and I at the marina restaurant. But I digress. Anyway, while her engine was running that Volvo 2030 seemed much quieter than your MD17C. My impression was that it seemed a good bit of the MD17C noise was related to vibration being transmitted through the engine mounts.

One other thing I noticed about Shatoosh was that the installation of her new Volvo engine necessitated cutting out some of the back end of the engine box (hers is the earlier style box like ours where you have to swing open the cabin wall & lift the whole box up), and had a little detachable wooden box that one had to remove before lifting the engine box.

So anyway, while thicker sound proofing may help, there's still the issue of vibration and I don't know what can be done about that short of adding a AquaDrive type CV/thrust bearing with soft isolating engine mounts, and I'm not sure you'd even have room in the engine bay short of major surgery. All that said while our boat is quieter, your boat is a lot faster than ours, we top out at 6.5 knots with our 24 ponies turning 2,350 RPM.

We'll be thinking of you when we & WillieC are up in BC this summer.

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[Sunsetrider]

My reply was trashed by pushing the wrong button. Ggrrr.

Great pics Steve - thanks! They also serve to remind me that summer will indeed return to these parts.

My diesel course demonstrated how the rubber bushings in the engine mounts compress over time, so I have no doubt that is a major factor. One does what one can and hopes for the best.

I am giving some thought to using the excess insulation (I over-ordered) under the cockpit floorboards. There may not be sufficient clearance.

[WillieC]

Don't forget to seal any gaps, and you will find plenty of those. There are better products available, I am sure, but I keep a chunk of 1/2" backer rod on board for misc rattles and gappage.

I stapled it to the bulkhead wall at the front of the engine cover, just followed the edge all the way around the funky step recess at companionway. Also look closely on the battery side down low. Lots of gappage there. I also jam short chunks of it in rattle-y cabinet doors, sort of like the wads of paper towels and McDonalds wrappers I jammed in all the air gaps in the dash my 56 VW back in the day. The border guys were VERY interested in that, so I had a prolonged visit with them one day at the Alderbrook crossing into BC. A Long Time Ago.

[DesertAlbin736]

They also serve to remind me that summer will indeed return to these parts.

In these parts we dread the coming of summer, hence our escapes to BC. It means heat, heat, and more heat. Exceptionally dry this year even for our usual desert climate, and right now there's an 8,600 acre wildfire raging out of control north of Payson in the Ponderosa Pine forested high country, prompting evacuations & several structures destroyed.

This is what our inside cabin thermometer often looks like this time of year. In degrees Celsius that translates to 49.7 and 51.4 respectively, essentially half way to boiling.

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[Sunsetrider]

Don't forget to seal any gaps, and you will find plenty of those. There are better products available, I am sure, but I keep a chunk of 1/2" backer rod on board for misc rattles and gappage.

I've been trying to figure out what I can use as a gasket around the bottom of the cover, and that stuff looks like it might do the job. I am not familiar with the term "backer rod", so will see where one might find it.