Your Opinions on Volvo D-6 310 HP engines

[trit21]

I am asking for opinions on Volvo D-6 310 HP engines. Currently looking at a boat that has these engines, 600 hrs and was wondering if anyone has opinions or have worked with these engines in the past. Boat has twin Volvo's and weighs about 16,000 lbs dry. Thanks for the comments.

 

[fwebster]

They don't seem to be too popular in our area. The only Volvos we see are a few re-powers. This is primarily because Vovlo's dealer network for service is sparse in this and certain other parts of the country. Just be sure you can get them serviced and repaired in your neck of the woods. The D-6 is a new electronic common rail engine with turbocharger and aftercooler and dual overhead cams.......the average Joe at the boat yard, ain't gonna fix it when it breaks.

I will say that a guy in our marina repowered an Albin with bobtail D-6 Volvos and, as a neighbor 6 boats away, I love how smoke free his new Volvos are..........his old Volvos smoked so much that mosquitos weren't much of an issue for anyone nearby.

 

[sprink56]

Frank,

Not to hi-jack this thread but on a similar note...what are your thoughts on Yanmar? I am seeing more and more re-powers around this area using them and I am always trying to learn what I can. Most of what I have seen locally are Gas to Diesel retrofits that look pretty good. I heard of one in particular that I want to look at if nothing else to see it...a 90 model 42 DA with twin Yanmar 6LY's with 350 HP. The owner replaced the 2: 454s and from what I hear the performance and fuel consumption numbers are dramatic. Have you seen any of these on the NW Gulf Coast ?

This particular boat is in and around the old Ravenswood Marina and yard in Dania and I am tempted to go look at it.

 

[Spot]

+1 for Yanmar, another name for BMW. We have seen quite a few folks repower from 454's to the Yanmar here in the NW.

 

[Spot]

In Oregon there are 6 Yanmar dealers and 1 that is 1/2 block from my marina. I found 1 Volvo dealer 225 miles north in Seattle. Not sure where you are but that might help me to make the decision.

 

[sprink56]

In Oregon there are 6 Yanmar dealers and 1 that is 1/2 block from my marina. I found 1 Volvo dealer 225 miles north in Seattle. Not sure where you are but that might help me to make the decision.

West Palm Beach, Fl...with NW Gulf Coast I was referring to NW Florida ...Gulf of Mexico.:thumbsup:

In any case, Yanmar is making a big footprint here and this is a major marine market.

 

[fwebster]

John,

I like Yanmar engines..own 2 of them in industrial/ag. applications. Both have been bullet proof and are very well built, but they are low speed diesels and turn about 22-2400 rpm. I think one of the reasons that Yanmars are such a popular repower for 7.4's is because their power to weight ratio is excellent. For me, their down side is that they are light weight high rpm engines, rated at 3300 rpm/3100 continuous. That means they are likely to be louder and have more vibration than a comparable hp Cat or Cummins engine, which were the standard power choices installed by SR in these boats when they were maanufactured.

Note, to avoid another discussion about my being anti-Yanmar (which I am not), the vibration I worry about is not due to higher rpms, but instead, is due to the fact that the manufacturer has lightened the rotating mass and weight of the rotating assembly to achieve higher rpms. Therefore, at lower rpms, the rotating mass isn't great enough to dampen the "shake" created by combustion pulses and the engines vibrate.

As far as performance is concerned, I would expect that switching from 310-340 hp gas motors to a higher hp diesl to give any heavy boat a shot in the arm/kick in the pants.

Incidently, I priced that repower from Mastry Engines for my 390EC. Some 12 years ago, it was an $80K major project.

I guess if I were boat shopping, I think you might find a Caterpillar or Cummins powered 42/44/45DA for about the same money. Those were standard engines for the boats and all the engineering was worked out by Sea Ray before the boats were offered for sale, not in the aftermarket by engine or boat yard "specialists".

 

[sprink56]

Frank,

Got you loud and clear. I'm suspecting that there has been some significant evolution in this Gas~Diesel retro-fit business in the last few years. I was surprised to see Yanmar now out with a serious sterndrive/diesel package taking a run at the "old school".

Of course no one is usually going to tell you what they did was marginal or didn't work well but we are now seeing some decent reviews by Boat Test on some of these jobs on older Topaz and Bertrams. The numbers I am seeing are about $50K~$55K to do it A~Z depending on whether you keep the original running gear configuration. This is about 1.5~1.75 vs. new gasoline. A man has to run the curve for himself to determine if this meets his particular situation/needs. Seems that this swap is meeting those needs with increasing regularity.

As far as the low speed vibration is concerned, one explanation circulating is the idea of a "dual stage" fuel injection that takes much of the shock and knock out of the ignition/power stroke by starting the burn on the compression stroke....maybe it works.

If I can go look at that 42 I'll take my Nikon and fish eye lens and get some pics. I'm curious to see how it was engineered.

 

[fwebster]

Every repower is different. On the pre-'98 390EC in particular, the job was huge and included new transmissions since the OEM engines were counter-rotating, new shafts to chance from 1.25" to 1.75" dia shafting, new 4 bladed props to replace 3 blade OEM's, new generator, new fuel system plumbing to add return lines, etc. etc.

The real interesting Yanmar package to me was the 4 cylinder 240hp diesel that weighs about what a small block GM with marine package does. I've run one pair in a 300WE that was an absolute rocket. Not enough for a larger boat, but up to a 390EC, they would likely be a decent choice.

 

[sprink56]

Admittedly this stuff becomes speculative but interesting to discuss. What I find intriguing is Yanmar's timing in bringing a serious diesel/sterndrive package to market at the same time Merc is phasing out the Big Block GM power because...well the General isn't casting them any more. Kind of throws the door open for that 350~400 HP/450~500 Ft. Lbs TQ "sweet spot" that GM has owned for decades. That's the preferred package for the popular size "pocket cruisers" that Sea Ray/MerCruiser/Brunswick has owned for many years.

You have to know that Yanmar is looking for a viable "sleeping buddy" to sell this package. If I am Vic Porter, Jr at Formula or with Wellcraft, Cobalt or Century...I'm taking a long hard look at this power package to get away from "sleeping with the enemy" so to speak.

 

[K-9]

:grin:let me ask (not hijack) who has gone from GAS TO Diesel?:thumbsup:

Frank,

Not to hi-jack this thread but on a similar note...what are your thoughts on Yanmar? I am seeing more and more re-powers around this area using them and I am always trying to learn what I can. Most of what I have seen locally are Gas to Diesel retrofits that look pretty good. I heard of one in particular that I want to look at if nothing else to see it...a 90 model 42 DA with twin Yanmar 6LY's with 350 HP. The owner replaced the 2: 454s and from what I hear the performance and fuel consumption numbers are dramatic. Have you seen any of these on the NW Gulf Coast ?

This particular boat is in and around the old Ravenswood Marina and yard in Dania and I am tempted to go look at it.

 

[fwebster]

Not very many owners do because of the cost, but there are a few out there.

Most of us decide to upgrade the entire boat rather than just the engines since the better part of $100K usually pays a lot of the trade difference. besides, who wants to own an old boat with a basis = 2X the replacement cost, which is about where you end up if you dump $80K in a '92-3 gas 420DA.