Quote:
Originally Posted by Mollers
Ahh. no.
A Merc (GM) 5.7ltr V8 puts out 260hp and more torque than the Queen Mary as it's in a very low state of tune.
A 3ltr TDI BMW lump with virtually half the cubes, would be a total wet fart by comparison.
Small capacity, diesel turbo/intercooled engines don't marinise well due to their narrow powerbands. No gears on a boat, it's all about grunt right through the rev range. 
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Hmmm, well my knowledge of petrol v turbo diesel is quite vast, tuned & standard stuff. So I pulled up some dyno plots as reference.
530d lump, grey lines are stock, red lines are tweaked
And the Mercruiser lump think its the pokier one listed here obviously
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So the TD lump makes 500nm or 350ft/lb ish at 2k and peak hp is at available for 2/3 of the rev range. The V8 graph starts at 2500 rpm with 360ft/lb
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and only makes its power in the top 1/4 of it rev range.
So according to those graphs the TD is pokier up till it runs of puff at 4500rpm, a tweaked one makes 150% of the V8 torque & will use 1/3rd of the fuel to do it
So going by that I think the little 3.0 smoker would need a V8 spec outdrive at least