Mercruiser Diesel vs. Volvo D4

melangeoff

melangeoff

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Hi all,

As RIB owners there's nothing worse than a stinky Diesel but now we're switching to the dark side and buying a 25' Cruiser for next season and don't know which Diesel engine to choose!

The Mercruiser Bravo III is the obvious choice from a financial outlay point of view but is it any good? Does it chuck out too much smoke and odour compared with the more expensive and arguably superior Volvo D4 series?

Cheers, Melangeoff
 
I would be more worried about using the Bravo III leg as they are notoriously un reliable whereas the volvo unit pretty bullit proof for the same torque and hp.
 
Thanks and please keep the feedback coming.

Just to provide a little more info on our exact dilemma, we are looking at the following 'new' engine choices:

Cummins/Mercruiser 4.2 MS 230 Bravo III 230 HP
Volvo D4 DPH 260 HP

In this case the Volvo is 70Kg heavier and 5K more expensive, so you can see why the choice is not Black & White for us.
 
Go for the Volvo D4 260hp, a fantastic fast and economical engine, I have one on my Larson 240 Cabrio and it is superb. A true 39 knot boat with ultra light EVC controls.
 
mercruiser seem to get a lot of bad press, enough to make us think long and hard about buying our current boat with merc diesels fitted. Our swas not new and is fitted with 180HP D3.6l's but we have no regrets. Our previous boat had volvo's and by comparison they seem to smoke a hell of a lot less at low speeds.

As for the leg we have Bravo II's which we have been pleasantly suprised by, previos b oat had volvo duo props and we think the bravo's give easier low speed manouverinig over all. Also having had a volvo leg fail due to water ingress/oil loss I like the fact that the merc leg has a remote oil tank in the engine bay.

Also the difference between a 4 and 6 cylinder engine should not be forgotten, 6's will always be smoother and quieter.
 
I have a pair of Cummins-Merc 4.2 L D300 and there is no smoke, you will not have a problem with the mercs from that point of view.

Mine have been very kind to us (now two years old.)
 
D4 260's belter motor, revs hard, mucho torque and very economical, not a huge difference between them and the D6 310's but much lighter at over 100kgs in the difference.

Resale will be better too.
 
Thanks for all your feedback so far everyone. This is our first ever posting on www.ybw.com and we are well on the way to making an informed decision with a little help from you guys.

Please keep the feedback and personal experiences rolling in.

Thanks, Melangeoff..... /forums/images/graemlins/smile.gif
 
I did ask once whether Volvo's were unreliable as there were stacks off posts with problems or whether there were just more of them so got reported more... never really got an answer.
 
I haven't heard of much trouble with Merc blocks, it's their BIII outdrives that are problematic (corrosion and gear troubles). The other merc outdrives vary: the other Bravos (like BII) seem quite robust, and at least the Alpha isn't megabucks to fix when it does crunch one last time.

Volvos have weak spots too. With the older stuff, it comes down mainly to maintenance, but there are issues specific to each engine that you can't generalise about. e.g. valve train on KAD44/KAD300, pistons on early KAD42, electronic gremlins on latest D4/D6.

Overall, I'd rather have the Volvo, especially the D4-260 which gets good reviews from everybody, and is way ahead on technology. I've had AD31's and KAD32's, and they have been v.reliable.

dv.
 
At this moment in time I would buy with volvos but if getting the right boat is more important then you can live with the Mercs no problem. Make sure the legs are of the X variety with diesels.

Also make sure you have a reliable local service agent for the ones you buy.
 
Hi Pete. Welcome back, did you sell your Larson? Saw it at Swanwick at the 2nd hand boat show with a sold ticket on it.
Geoff.
 
Hi Geoff, The Larson sold before the show started, the new owner has taken delivery already, the completion of the sale takes place this Wednesday.

I was very sad to see it go, a fantastic machine with immense power and one the new owner will have the time of his life in, I was very pleased and happy to see that I was able to help a dream come true for someone and that it went to a good home, it was after all still only a baby at ten weeks old when it sold /forums/images/graemlins/grin.gif.

I am sure the new owner will come out of the closet on here on Wednesday evening, and there will be loads of stories of adventures in her to follow /forums/images/graemlins/wink.gif
 
I think the 180 was based on the old BMW engine, how long ago was that ?

Two years ago I found my ideal boat but it had Brand new Cummins Merc 4.2L D300's (on shafts ).
I asked on here as I was concerned but overall the advice was good.

I bought the boat and the difference between the CM and Volvo are unbelievable, the CM are a pleasure to own, no black smoke even on a damp cold winter day.
No black end/stern quarters even after 500nm there is no need to clean the stern.
The tender stays clean year round.

I know Volvos have improved but I still see neighbors brand new boats with mucky bums and black tenders even after 200nm.

The CM are a pleasure to own and service parts are incredibly easy to get to. There are two oil filer points for example just so you can reach one or both with ease.

The engines are very smooth and start well.

The engines have so far been 100% reliable.
One out of 4 fan belts snapped but that didnt affect performance and was easy to exchange.

The only concern I have is with residual value due to the anti Merc Volvo owners that should not be under estimated.

There is a divide between older owners wanting Volvos (mainly as have more spendable income and buying larger boats)
And younger owners going for Cummins-Mercruiser who have grown up and started with Petrol mercruisers as I did.

At some point I hope the tide will turn in favor of the CM but who knows

At my boat club the old members used to favor Perkins and the younger members started to chose Volvo, those members are now the older brigade and the youth is choosing Mercruiser,

In summary the Cummins-Mercruiser are the better engine but you gamble residual values.

This was taken on a very cold damp morning with cold engines
e7ca79cde4fc8499914023086256ddb5.jpg
 
Well there is the usual amount of duff advice being spouted again, with 'my mate tales of woe'.
Reading between the lines some of these faults are down to bad maintenence.
I've installed both motors, and the Volvo while good still smokes from cold, is much heavier, and its a 4 cylinder, and these are not as smooth as a 6 cyl as any decent engineer will tell you, even with balancer shafts, plus it has a compressor for added complication and maintenance ( read all the threads about belts).
The Mercruiser isn't as hi-tech as the Volvo yet it is the most smoke free engine I've seen in this class, a cigarette has more smoke!, yes there were some issues with the earlier drives I rebuilt loads, but the newer X series is sorted and Mercruiser have the Mercathode system as standard.
Water ingress is virtually unknown because of the inboard oil tank which maintains a positive pressure in the drive, I must have repaired on average 3 Volvos a month for water ingress over the past 10 yrs and about 10 Alphas and no Bravos in the same time period.
Also we have never done a head gasket on a Merc or even opened one up come to that, but rebuilt plenty of Volvos. Did a KAD 32 head gasket yesterday for a mate, and I am trying to give up the spanners!
For the weight you can't get more horspower, (Yanmar don't have a drive)
we have the 4.2 320 D in our 27 foot Artic Blue RIB (1.6 ton) with a BI drive and it does 52 kts GPS and cruises at 48kts.
It sounds great and is incredibly smooth, and pretty economical.
You could go on forever with tales of woe from both sides so at the end of the day you will pays your money and takes your pick.
 
There isn't any global conspiracy against Merc from Volvo owners.

When people buy a boat engine, they want to make the obviously "right" choice, and not an obscure one that they will be forever trying to justify to the next purchaser on technical grounds alone.

Somewhere along the way, boat buyers & builders in Europe made a choice to go with Volvo in fairly large numbers, and that dominant position won't be lost unless Volvo do something incredibly daft: availability of dealers and parts ensure this.

In the states, people are choosing Volvo petrol sterndrives over Merc because Volvo is perceived to be a better product. Again, no conspiracy, just word of mouth from happy or unhappy owners. For example, Bravo III sterndrives that corrode to scrap in a couple of seasons: Click Here

dv.
 
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