What's the difference between Volvo 63P and D6 370hp engines?

[Deleted User YDKXO]

What\'s the difference between Volvo 63P and D6 370hp engines?

We had a day out in the Solent on a chartered Sealine F43 yesterday. I used to own a Sealine 410 which is the previous version of the F43. My boat had Volvo 63P engines which revved to 2800rpm and produced 370hp. I assumed that the chartered F43 would have the same engines but I was surprised to see that the engines that were fitted revved to a much higher 3500rpm. The skipper told me that the engines were D6 units developing 370hp, the same as the 63P units but at a much higher rpm
The reason that I ask this was that the D6 engines fitted to the F43 were noiser and more vibey than I remember my old 63P's were. I put this down to the fact that the D6's have to be revved higher to get the same power. Checking the Volvo website, the D6 and the 63P seem to have the same engine capacity, 5500cc so I'm wondering if the D6 is a development of the 63P block or not? Either way, the D6 does'nt seem to be much of a step forward over the 63P as you have to rev it far higher to get the same power as a result of which it seems to be noisier
Anyone else compared the 63P to the D6?

 

[Bandit]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

The way i understand it the D6 is a completely new unit .

I have 63p's good final grunt but slow acceleration.

The D6 boats i have been on have a completely different power curve and the D6 seems to accelerate much better.

The Volvo Penta website have the old engine 63p data and the new D^ info to compare.

 

[[2068]]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

Just from the spec sheets, I'd expect the D6 to be better on Fuel Consumption, emissions, and soot, plus smarter "out of the hole", as the torque curve is more evenly spread out. 63P has a large turbo which doesn't really spool up until 1600rpm.

Downside of D6 is higher running RPM, as pointed out.

dv.

 

[volvopaul]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

Hi Mike the 63p is the old 60b/c and 61a 62a block at 5.5 litres, this eingine has climbed in hp rating over the years to a max of 370 in 63p form as they changed the turbos and coolers to cope.
IMHO the p engine is cheaper to run and maintain it can be maintained by the average diy mechanic as its totally mechanical, no edc sensors or computers etc.

The D6 is a 4 valve per cylinder common rail fuel system much more inline with todays technology, and is designed to keep up todays requirements.

 

[MapisM]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

Ok, but what about Deleted User's doubt re. requiring 700rpm more to achieve the same power with the same displacement?
I don't have an answer, but it seems to me a good question and I'd also be curious to hear the reason - if any.

 

[volvopaul]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

Well mapis the reason is a totally different design of engine higher revving engines run totally different creating torque at higher rpm as compared to the older design engine, but IMHO at a cost, the new d6 will not do the amount of hours before it needs a rebuild compared to the 63p engine despit what you might hear from anyone at volvo, ive heard all sorts of failure stories about these engines, crank problems, edc shutdowns etc and once thats happened your out there miles from home at 1000 rpm till I can get to it and sort it, the fuel has to be cleaner as common rail high pressure pumps dont like water and dirty fuel, and your talking thousands to replace them.

 

[Divemaster1]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

Also believe that the D6 / D4 etc., are throwaway blocks ..... ie if you damage a cylinder, there is no way to re-condition the cylinder (no liners, over sized pistons etc.)... so throw away block and buy new one at $$

 

[RogerRat]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

Interesting question, My P38, 'Panache' had 63ps' and they were smooth but slow to get going. The turbos whistled which became a basic characteristic. Bit smokey, hence the threads on soot deflectors. Cruised well at 24-2500 rpm. giving 24-25 knots. Max. revs 2750 / 30 knots.

My latest, 'Houston' Targa 40 has D6 350's on outdrives. Very grouly sound, amazing pick-up through the range and easy cruising at 25-2600 rpm gives around 27 knots, max rpm 3550. Max. Speed [word-removed]

(must be classified) /forums/images/graemlins/wink.gif /forums/images/graemlins/grin.gif

 

[Garryt]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

I've got 63P's fitted in my F43, which so far (touch wood) have been excellent. Yes, perhaps they're a little slow to accelerate, but as I don't have a sports boat, this is not a trait that worries me.

My revs peak at about 2800 (ish) ( have had about 2900, when the boat has been cleaned and with very little on board), but my question is, what max sustained cruising revs would be acceptable for this engine?

I tend to cruise at around 2300 and generally achieve around 20 kts fully loaded at these rev's (also fitted with rope cutters / strippers).

 

[Deleted User YDKXO]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

I think Volvo have always said 200rpm below max rpm which means whatever max rpm the engines are getting at that particular time taking account of load and fouling so, if you're consistently getting 2800rpm even with the cutters and a bit of fouling, then upto 2600rpm would be your recommended cruising rpm. But it would also be a good idea to work out your most economical cruising speed which may be less than max rpm - 200

 

[jimmy_the_builder]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

I've got D6 435's, and the max cruise recommendation is 3150 rpm, ie 90% of WOT. At 3150rpm they consume 49lph each; 83lph at WOT.

Cheers
Jimmy

 

[Garryt]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

How often is it sensible or advisable to apply WOT to these type of engines (63P's for example) and for how long a period should you let it run at WOT?

 

[Deleted User YDKXO]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

Good question and I don't think there's a correct answer to that. Personally I wind up my boat to WOT for a minute or 2 every trip usually on the way back to the marina just to check what max rpm is being achieved and whether the guages are correct. For example a rise in coolant temp at WOT could be indicative of future probs at cruising speed

 

[Wiggo]

Re: What\'s the difference between Volvo 63P and D6 370hp engines?

I think they have a 10% duty cycle for their max rated power, so no more than 1 minute in 10.