Engine comparison

andy59

andy59

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Old school TAMD 74l 430 hp v new tech D6 435 hp in same hull . On paper the 74L makes a bucket load more torque than the D6 so would I be right in assuming that both boats would have similar performance ( ignoring economy and smoke issues ) . thanks again for any opinions .
 
So are the older TAMD the heavier, I'm assuming they would be ? 700 kg is a least some 5-8% of the total weight of a boat requiring that sort of power, which should roughly equate to the difference in performance for the same power output.
 
TAMD74 = 880kg (bobtail)
D6-435 = 594kg (bobtail)

Difference: at least +572kg on a twin engine boat

TAMD74 slightly higher fuel consumption in general. The weight increase means you'll need more power to reach any given speed = higher consumption. A little speed lost on the top, but improved acceleration would probably more than make up for it.... the fun factor should not suffer.
 
I was thinking that as well Hugin , but I understood that a boats max speed clean would give a good indication of general economy / cruising speed with a cushion for having a dirty hull . Ultimately I will sea trial the boat to check "actual" performance .
 
Sea trialed p42 with D6 435 in last week just antifouled and props like new max speed was 28 an average both ways ,28.8 with tide.
D6 has all its woes and uses light allot cased HS 85. Tamd 75 is heavier but depends wether it has chocolate zf280 or bomb proof twin disc which Is huge and certified to higher spec hp rating.
75 is a cheaper engine to service but not by much unless you use pattern filters.
D 6 is very smooth over 75 but builder puts a lot of sound deadening on grp floor panels , 3 layers inc carpet.
 
Hugin said:
TAMD74 = 880kg (bobtail)
D6-435 = 594kg (bobtail)

Difference: at least +572kg on a twin engine boat

TAMD74 slightly higher fuel consumption in general. The weight increase means you'll need more power to reach any given speed = higher consumption. A little speed lost on the top, but improved acceleration would probably more than make up for it.... the fun factor should not suffer.
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D6 gives 28 knots
75 480 gives 31 knots.
Any boat can vary depending on its weight.
 
Should be ok . Basically they were eaten alive in the broom 450 with a D9 500 on the front of it and rated at exactly 500hp at stated revs. You will heR it chatter as the gears wear, but they mostly have self destructed , aqua power.on here knows this all too well.
 
volvopaul said:
Should be ok . Basically they were eaten alive in the broom 450 with a D9 500 on the front of it and rated at exactly 500hp at stated revs. You will heR it chatter as the gears wear, but they mostly have self destructed , aqua power.on here knows this all too well.
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Yes Paul, know that one well !!, only ZF280 boxes I know of that failed were as said above, the D9 500 had far too much torque for it to cope with, never had a problem when fitted to 74 as was a bit more gentler on the torque.
 
I maybe talking craap here but in my view the D6 435hp is at the top end of it's power output with associated strains on components and known issues along with new age electronics. To me that adds up to potentially big bills and more to go wrong.
From what I'm aware the 74p's at 430hp are at the lower to mid end of their power rating, they are based on truck engines and fewer potential electronic issues so less likely to need as much maintenance or money thrown at them, that equates to more time playing which is what we do best.:cool:
Anyway my two cents worth.
 
crazy4557 said:
I maybe talking craap here but in my view the D6 435hp is at the top end of it's power output with associated strains on components and known issues along with new age electronics. To me that adds up to potentially big bills and more to go wrong.
From what I'm aware the 74p's at 430hp are at the lower to mid end of their power rating, they are based on truck engines and fewer potential electronic issues so less likely to need as much maintenance or money thrown at them, that equates to more time playing which is what we do best.:cool:
Anyway my two cents worth.
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Number 1 I am not a VP person and have no intention to offend however this is sheer dinosaur logic.

I did get involved in a TAMD 72P with valve drop issues whereas D6 435 is rock solid motor. Yes the old 70 series has 856 Nm of torque vs 767 Nm however D6 435 torque rise is better and in terms of transient response D6 leaves TAMD72 430 dead in the water, cart horse vs race horse.

In this power node has to be a no brainer........D6 every time.
 
I am also bowing to superior knowledge , but the spec sheet I have here for the TAMD 74L shows max torque of 1300nm at 1400 rpm and 1202nm at max rpm . I would totally agree D6 is a superior modern tech motor but I am just trying to get an idea of comparable performance before I have to schlep of to the SOF . As crazy4557 says , I to am also always interested in your opinions .
 
andy59 said:
I am also bowing to superior knowledge , but the spec sheet I have here for the TAMD 74L shows max torque of 1300nm at 1400 rpm and 1202nm at max rpm . I would totally agree D6 is a superior modern tech motor but I am just trying to get an idea of comparable performance before I have to schlep of to the SOF . As crazy4557 says , I to am also always interested in your opinions .
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Andy apologies I was looking at 72 also VP quote torque at rated speed and not at peak torque for some reason.

HOWEVER having looked at the shape of the power/torque curve of D6 it is easy to see why at top ratings does not fare well on shafts and attract comments vs bigger iron.

D6 was really designed by Deutz to optimise VP out-drive system, and like most work out of Deutz it is very well engineered. Detest the term 'stressed' no company builds engines which are designed on a knife edge and stays in business, suspect VP who picked up the base design from Deutz and Volvised it probably developed the D6 435 around a 500 hp durability test model so no concerns in that direction.

I may be proven wrong however it is hard to see how the 5.5 litre D6 can grow much further as it has light duty features for example a timing chain and not gear drive to the camshaft.

Volvo purchased a piece of Deutz in the late 90's as development costs of the D12 had left them drained and their 10 liter engine required replacement with a clean sheet of paper. The old 60 series also required replacement in the same time-frame and Deutz had a real nice 7.2 liter engine which Deutz were prepared to produce for Volvo automotive applications.

Volvo got on designing the D9 which turned out to be a bit of an engine planners myopia, too much iron for the given displacement. As soon as D9 was done planning started on growing it to D11 which SHOULD have replaced D9, however increase in displacement made this motor far more expensive so both displacements were retained.

VP had no access to the Deutz 7.2 for marine applications so they were left with the big hole between D6 and D9 and relations between Volvo and Deutz on sharing emissions R&D on the 7.2 started to sour.

I 2007 Volvo unexpectedly purchased Nissan UD commercial vehicles of Japan who appeared to be in terminal decline. UD stood for Uniflow Diesel as the company produced uniflow two stroke diesels in the 50's and had always enjoyed a good reputation for engine design and the name became Nissan UD now standing for ultimate dependability.

Big plus for Volvo was that UD had real nice up to date engine platforms, in particular a 7.8 liter 6 cylinder common rail motor and by 2011 Deutz was on the way out being replaced by the Japanese built UD 4 and 6 pot motors now branded Volvo D5 and D8 and at Euro 6 the UD engines finally took out Deutz completely.

Looking at the light, power dense common rail UD 7.8 it could easily cover from 450 to 600 hp taking out D9 completely and prove a worthy successor to the old Volvo 70 Series. Will it happen at Tier 3 or do we wait until Tier 4?
 
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