MAN 800hp D2848 - Sea trial - Annoying and tiring engine sound?? on Princess V55.

[yossy]

Another question to the forum who gave me much appreciated advice on the gelcoat questions I had earlier regarding this Princess V55.

Now I have had the sea trial! And now my question is about sound on MAN engines and the model D2848 LE 403, 800hp, year 2000. Engine hrs 700.

Overall the performed very solid on the sea trial. The engines seem to perform very well. Top speed with full gas and full water and 5 men was 35,5 knots on GPS. My overall feeling of the engines is that they are in really good shape and well taken care of. Temp pressure revs etc looked good all the way. I listened to each engine at a time with hatch open, at different revs, and they sounded good.

However my concern is the sound when driving the boat. I can't say I have much experience from similar boats and similar engines. I understand big engines like this will have a big sound. But the sound from around 1200rpm up to 1900 rpm is quite pitching and whining, and I fear that it is an annoying and tiring sound. Around 1900rpm with speed of 29knots whining sound goes down. Broker and mechanics says boat is better above 1900rpm because turbos are in a better rpm range? I know my previous kad 300 had different revs where it performed more stable, either where no turbo at all or where the turbo was working with more pressure.
Should it sound like this? Will I get used? Could it be because turbos should be replaced or something?

At lower rpms there is no whining pitching sound but it is quite a big sound. Like you know on a big truck or buss, but I guess that is as it should be on bigger diesels? On my previous boat with twin kad 300 I never reflected that the engine sound was disturbing. Most of the time we jumped into the boat had a glass of rosé and went in 9 knots to the closest sea restaurant and chatted and had a good time. I notice big sound difference if you are in the front at the seats at the helm or on port side, compared to sitting in the cockpit u-sofa where sound is a lot higher especially at higher revs.

Please help with input and views on this. I'm about to make a decision on buying the boat...


/Krippe

 

[yossy]

I just listened to this clip of a similar MAN Marine engine but just a little bigger and I hear the same whining sound (see link below and go 1,19 into it). So I guess the engines sounds just like they should? BUT then my question is Isn't this annoying and tiring and what do people that comes along for a ride think of the sound? Most of the time I'm going to drive around 9knots. The whining sound is not there at that speed I guess but the sound is still quite noisy. Will passengers/friends/family and myself feel it is disturbing? Are not all bigger boats +50 fot with Volvo D12s MANs and CATs suffering the same situation? Or is big sports cruisers substantially more exposed to this?
Confused on another level I guess...

 

[ProDave]

Buy a raggie and enjoy silent (but slower) sailing.

 

[jfm]

My guess is there is nothing wrong with the engines, though of course I'm only going from your written description of the noise. I have driven a couple of hundred miles in a boat with the bigger MAN V10 (1100hp) and those engines have a very significant turbo whine around 1300-1900rpm, which is normal. Your 8V version might be the same, though I have not driven a boat with the 8V engine

Compared with KAD 300 the sound on any 800hp is going to be much "bigger". Different engines sound different (the Volvo D12 has plenty of mechanical noise but little turbo whine, for example) but they all sound "big". You're just going to have to get used to it, and it will soon become normal

Sports cruisers are of course always going to be MUCH noisier than flybridges. On a flybridge the engine noise is very nicely muted and way nicer on a long run than a sportscruiser set up. But let's not start off the fly vs sportscruiser debate!

At the next size nodes up, say 1100hp, then 1600hp, the engines sound bigger again, and it becomes the new normal after a few weeks of living with the boat. If you go inside my engine room (2x cat c32) at 1900rpm the sound feels enormous and you need ear defenders

Good luck

 

[SwedeSkipper]

Hi Yossy,

I have a V58 with MAN800's. I agree there is a whining sound, but I don't think the sound is more disturbing than on my previous boat which has KAD300's. As a matter of fact, the sound/noise level is no problem at all when making conversations with the crew.
Maybe you just need to take a look at the sound insulation by the engine hatch?

I don't think you will be bothered by the sound.

A word of caution on the MAN800's: AFAIK, you are supposed to service the injectors every other year. Make sure you get documentation that is has been done.

 

[kcrane]

Sports cruisers are of course always going to be MUCH noisier than flybridges. On a flybridge the engine noise is very nicely muted and way nicer on a long run than a sportscruiser set up. But let's not start off the fly vs sportscruiser debate!

Now I could be wrong, I often am, but I have a vague recollection of you commenting in the past that you shouldn't start up a debate, make your own point, then say "debate closed"

On the other hand you are darn close to some big thrashing metal bits on a sports cruiser which does get tiresome after a while. After a 5 hour trundle this last weekend I found myself wondering how much quieter IPS would be.

 

[jfm]

Now I could be wrong, I often am, but I have a vague recollection of you commenting in the past that you shouldn't start up a debate, make your own point, then say "debate closed"

On the other hand you are darn close to some big thrashing metal bits on a sports cruiser which does get tiresome after a while. After a 5 hour trundle this last weekend I found myself wondering how much quieter IPS would be.

Haha, fair point K There are many points to debate about fly vs s'cruiser and which suits certain types of use (wind in hair, not losing sight of young kids, cardigan wearing, and so on) and I'm happy to debate those if you wish . However, there is one point not much disputable which is that in a s'cruiser you are separated from 2 diesel monsters by a pathetic layer of sound insulation foam and one sheet of GRP or plywood (muchly-behatched) deck, whereas on a flybridge you are a long way and another lined deck apart from the engines. In my Sq58s and 78s you can do 23-25knots and chat without raising your voice at all, whereas I think the noise inside a s'cruiser is quite a bit louder than that, and sometimes worse still if there is a hardtop

Just one of those things that goes into the melting pot, along with pipes, slippers chestwigs and medallions, when choosing a boat

Yup IPS would be quieter just because the engines are (generally) further back. Different s'cruiser models also vary a lot - at least I suspect that from my sampling of driving s'cruisers. For example if I compare two boats that I've done 100 miles+ in, namely the f'line targa 47 with D9s and f'line targa 50 with D13s, the 50 is one heck of a lot quieter than the 47 whether roof open or closed. Noise-wise the 50 is ok for long cruising whereas 47 isn't (just imho of course)

 

[DPH]

Test drove a boat with Man's and I personally could not live with the whine from the engines. However, happy to live with the Volvo D12s for hours at a time at high speed.

 

[Deleted User YDKXO]

Funny you should mention this because I have MAN D2842 LE443 V12 engines in my boat and I noticed a slightly irritating whining noise at about 1000rpm last week whilst out cruising. When you say 'mechanic', are you referring to an official MAN trained mechanic or a general engine fitter? Its certainly worth getting an engine report and oil survey done by an official MAN dealer who at least will know these engines well

 

[kcrane]

Yup IPS would be quieter just because the engines are (generally) further back. Different s'cruiser models also vary a lot - at least I suspect that from my sampling of driving s'cruisers. For example if I compare two boats that I've done 100 miles+ in, namely the f'line targa 47 with D9s and f'line targa 50 with D13s, the 50 is one heck of a lot quieter than the 47 whether roof open or closed. Noise-wise the 50 is ok for long cruising whereas 47 isn't (just imho of course)

This is one I agree on. When we pootle I juggle the throttles to get the engines in sync (I don't think they auto-sync at low rpm for obvious reasons) as the rhythmic booming is tiring even at low speeds. Fortunately at higher speeds it is self-limiting as once I have done 50 miles my hands start shaking and only a cold beer will stop it

 

[Deleted User YDKXO]

After a 5 hour trundle this last weekend I found myself wondering how much quieter IPS would be.

Apart from IPS, any boat with shaftdrive and V drive gearboxes puts the engines further aft which makes a big difference to noise and vibration. My last 3 boats have been Ferrettis, 2 with V drive arrangements and engines aft and 1 with 'standard' shaftdrive and engines under the saloon. The 2 V drive boats were noticeably quieter and smoother, particularly at the lower helm

 

[jimmy_the_builder]

There's also a difference in noise levels between hardtop sportcruisers, and those with just canvas (like, I think, the V55 under discussion here); with canvas-top s/c's there is definitely less noise reflection, and if you fold all the canvas away, there's quite a dramatic further reduction in noise. A s/c is never going to be as quiet as the upper helm on a f/b, granted, but cruising completely topless does generate some benefits ... (!)

 

[Latestarter1]

My guess is there is nothing wrong with the engines, though of course I'm only going from your written description of the noise. I have driven a couple of hundred miles in a boat with the bigger MAN V10 (1100hp) and those engines have a very significant turbo whine around 1300-1900rpm, which is normal. Your 8V version might be the same, though I have not driven a boat with the 8V engine

Compared with KAD 300 the sound on any 800hp is going to be much "bigger". Different engines sound different (the Volvo D12 has plenty of mechanical noise but little turbo whine, for example) but they all sound "big". You're just going to have to get used to it, and it will soon become normal

Sports cruisers are of course always going to be MUCH noisier than flybridges. On a flybridge the engine noise is very nicely muted and way nicer on a long run than a sportscruiser set up. But let's not start off the fly vs sportscruiser debate!

At the next size nodes up, say 1100hp, then 1600hp, the engines sound bigger again, and it becomes the new normal after a few weeks of living with the boat. If you go inside my engine room (2x cat c32) at 1900rpm the sound feels enormous and you need ear defenders

Good luck

I remember comments made by tournament fishermen regarding experience with CAT C 32's. Any drawbacks?.........'Like living with pair of locomotives under the boards'.

Designing a quiet diesel engine is like is like trying to design a quiet hand grenade.

 

[rafiki_]

Designing a quiet diesel engine is like is like trying to design a quiet hand grenade.

 

[Princess SD]

Hello, the engine access hatch had 2 handles that doubled as clamps when pushed down flush and pulled down the hatch hard against the surround. As long as the hatch is not warped and the levers do pull the hatch down hard, if you ensure that there us a strip of foam/sound proofing on the hatch where it sits on the surround you will find the turbo whistle is greatly reduced. Also if you trim the bow down a bit at 10-20 knots the load will be reduced and the exhausts noise escapes aft better. I was involved with loads of v52/55's and they were a bit noisy with the bigger v engines if the hatches weren't tight....good luck.

 

[kcrane]

There's also a difference in noise levels between hardtop sportcruisers, and those with just canvas (like, I think, the V55 under discussion here); with canvas-top s/c's there is definitely less noise reflection, and if you fold all the canvas away, there's quite a dramatic further reduction in noise. A s/c is never going to be as quiet as the upper helm on a f/b, granted, but cruising completely topless does generate some benefits ... (!)

Yep, agree with that, I keep the roof open as much as possible a) less noisy and b) nice to be in the open air

 

[BartW]

this is indeed the Turbo's sound
and I actually quite like it, sounds a bit like a airplane..

the exhaust of our MAN V12 are above the waterline,
quite impressive BIG sound coming out, head turning when arriving in Marina's, ;-)

on top of our FB it is surprisingly quite

 

[ari]

Most of the time I'm going to drive around 9knots. The whining sound is not there at that speed I guess but the sound is still quite noisy. Will passengers/friends/family and myself feel it is disturbing?

From my limited experience with big boats your passengers/friends/family will most likely feel Oh my god this is amazing! Look at this boat it's fantastic! It's got TWO toilets!! And showers! And there's a TV in the cabin!

Then when you open the throttles...

Wooooww!! It's like a speedboat! It feels like we're doing 100mph! This is the best day of my life, I love this boat thank you so much for taking me out on it!!

Any that do sit in the corner going hmmm... well... it's rather loud isn't it? are probably people you can live without on future trips anyway.

 

[yossy]

Thank you all for very appreciated input!!! A lot of valuable info for me as I have very limited experience with engines like these and size of boat like these.

Ari I like your post

From my limited experience with big boats your passengers/friends/family will most likely feel Oh my god this is amazing! Look at this boat it's fantastic! It's got TWO toilets!! And showers! And there's a TV in the cabin!

Then when you open the throttles...

Wooooww!! It's like a speedboat! It feels like we're doing 100mph! This is the best day of my life, I love this boat thank you so much for taking me out on it!!

Any that do sit in the corner going hmmm... well... it's rather loud isn't it? are probably people you can live without on future trips anyway.