Which engine choice?

[luicci]

So I get to choose an engine for my bavaria 37 sport, its either volvo penta
d4-300 or volvo penta d6-330. Will the boat feel underpowered with the
d4-300? Which one is the best choice?
Thanks

 

[Whitelighter]

Logic always says go for the bigger engine option as it will be ebtter for resale.

I dont think it will be under powered with the D4's - alot of boats that size dont even offer the D6's and start with the D4 260.

What is the cost difference?

 

[goochie]

I've been looking into this as I may have to make this same choice sometime soon. The D4 300 is a very heavily reengineered lump compared to the 260 - almost a different engine in some ways. I've driven a couple od boats with them in and they are surprisingly good. Lots of grunt, and certainly a lot quieter than the D6's. Also more economical if would think in your Bav, which is not the heaviest boat in it's class.

 

[gjgm]

dont know if its sorted but werent Bavarias supposed to be aweful at sound insulation, and the D4s damn loud engines?

 

[celtic_mist]

A Mate Of Mine Has The Bavaria 37 Ht With The Old Kad 300 Engines (285hp I think ?) & It Will Do 36+ Knots , So If Thats Anything Too Go By The D4 300 Should Be Fine .

 

[goochie]

Don't know about Bavarias sound insulation, but I've been in a boat with the D4's on shafts and they seem quiet compared to the D6's.

 

[Geoffs]

I don't know why the D4 is always said to be noisy. Mine is very quiet, and smooth. I sit not much more than a meter from it, and there is almost no sound insulation in the engine bay. The only slight annoyance is the sound of the supercharger. But that can be controlled, to a degree.

My D4 is quieter and smoother than CMD 1.7 and 170 hp Yamaha equipped boats that I visit. And it is certainly much quieter than my old 3.0L Mercruiser.

 

[luicci]

The difference is 7883.00 euros. Do you think that the d4-300 still be powerful when there is 10 people on bard?
thanks

 

[Whitelighter]

Fot that cost against the whole price of the boat go for the D6's. It iwll be much better for resale and probably a bit more efficient.

 

[Divemaster1]

D4 300 is a highly tuned engine
D6 330 is less so..

Highly tuned = more stress on egine and will require more TLC.
Highly tuned = shorter life span

So what are you going for 5 -10 year life before rebuild, or less as you'll pass the boat on to others before then?

My coce would be the D6 .... if I had to choose a V...

 

[gingie]

The D4 300 is not a highly tuned engine

In fact its entirely different from the old 210,225 and 260

Its a strengthened block, stronger crank and different pistons. Different heads and cooling system.

Inside the block in the lower half under the crank shaft area is a highly strengthened honey comb designed aluminium housing adding extra strength and rigidity to the unit as well as housing the balance shafts.

It simply is not a D4-260 chipped or turbo pressure tweaked. Different heads, turbo, intercooler fuelling arrangement.

 

[Geoffs]

Have to agree, just comparing to cars. My 1.9 litre diesel is rated at 150 bhp, at 4,500 rpm, and will clock up 100,000 miles this week. Thats probably equal to about 3,000 hours in boat terms. So 300hp out of 3.8 litres shouldn't be a problem, as long as Volvo have got it right, which is by no means a given!

 

[Divemaster1]

Higher stressed engine then ..

Why do you think it needs the inreased cooling, strengthened block, crank and all that.... They knew that the 260 "as was" could not take 300 hp outtake ... so watch for 260 issues appearing in a couple of years.....You take out more Hp of a given volume... more Hp require more air/fuel. More air fuel = bigger "bang", bigger bang = more heat to disperse of and more stress on block, crank etc.

I don't really care if it is a "completely different engine" ... I'd still go for the higher volume, lower hp to volume outtake option.

 

[segaerta]

Luicci,

I have a Bav 35 with twin D4-225's so the lowest engines. I feel it is by no means underpowered and is up on the plane very quickly even with 8 adults on it. Compare it with the boats a few years ago, these had 230 HP KAD42's for similar length and weight. However, I have not yet been at sea with my boat and don't know what it gives in a somewhat rougher sea where some extra power might come in handy.

Since I have no GPS ( a Navman 8084 is being installed this week ), I don't have a reliable indication of how fast the boat goes with these engines but I trust it will do about 30-32 knots at top speed and will cruise at 23-25 knots, at which speed I consume about 23 litres per engine (that's with 6-8 people on board).

Chooising between the D4-300 and D6-330, you have to ask yourself what you are looking for :

- top speed : I don't think top speed with the D6 will be significantly higher than with the D4 - and are those extra few knots worth the investment ?
- consumption : I don't think consumption will be significantly higher with the D6 as they will probably run at slightly lower RPM's for same speed
- smooth running : Maybe the D6 will run smoother or "sound" better (like in my car, I prefer the 6 cylinder over a 4 cylinder diesel)
- weight : The D4 is already a heavy engine, the D6 adds another 100 kgs per engine (= more than the average adult weigth)
- noise : Sound insulation at Bavaria is not existent : you have to add it afterwards or the dealer can do this. Personally, I rate my D4's as noisy (but I compare them to my previous V8 petrol engine and have no experience with other diesel engines of different vendors nor sizes). The noise in our 35 is too present at low RPM (eg doing river work) but bothers me less at cruising speed. Some guy in our marina has bought a Bav 35 with same engine package but with insulation. Going out on a trip with him later this year will tell me if his 2000 £ investment was worth it or not (although he has a hardtop which is always a little noisier than an open cruiser).
- resale value : I'm not sure about resale value in a couple of year's time ? I read the opinion of more experienced boaters that a boat with biggest engines retains its value better but with rising diesel prices how may that affect people's reasoning in a few year's time ( although D6 consumption may not be a lot higher than the D4, there may be a belief that smaller engines are more economical ) ... don't know.

If you have the option to try both, then do it. It will help you in taking your decision. But it's a lot of extra money that buys you a lot of extra equipment for the boat.

If I had the choise ( but i bought second hand a very young boat ) I might have gone for the bigger engines just because I love the extra power. But buying second hand, there's not always the ideal boat ( unless you decide to wait for ever ).

Good luck !

Best regards,
Alain

 

[[2068]]

With regards to fuel consumption, there's probably not much in it.

Bav 37 is a heavy boat weighs 8500kg already, so a couple of extra hundred kg mounted low down isn't going to hurt, so long as it doesn't make it trim to be tail heavy.

It it were me, I would probably go with the D6-330, not because the top speed would be higher, but because the cruise speed would be at slightly lower rpm and a bit more relaxed.

dv.

 

[luicci]

I decided that I'll go with the D4-300.
Thanks for al your help

 

[segaerta]

Excellent choise ... gives you another 150 HP over my boat but yours is slightly lenghtier, beamier and heavier. I'm sure it's more than enough for the occasional bltiz around the bay.