6.5 turbo diesel

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I'm just curious to know if anyone is using or has used a GM 6.5 turbo diesel, or even a 6.2 n/a as a marine engine.
I recently bought a 25' Starcraft Chieftain that has an I-6 mercruiser and just thinking of different options on how to repower it.
It would seem (the 6.5) would make decent power with a reasonable fuel economy with a dry weight of only 650 lbs...
 

smokeonthewater

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Yes been done...

Manifolds are EXPENSIVE and HARD to find.

This is actually the origin of my screen name... Had planned on putting a 6.2 diesel in the boat I had at the time....
 

Scott Danforth

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smokeonthewater

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Marine parts are made of gold painted black.
Marine DIESEL parts are made of gold plated unobtanium painted with refined liquified black diamonds......
 

Scott Danforth

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the OP could always run a Cummins/Mercruiser 4.2 liter, or a cummins QSB-4.5, or jump up to the QSB-6.7
 

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the OP could always run a Cummins/Mercruiser 4.2 liter, or a cummins QSB-4.5, or jump up to the QSB-6.7

Woudn't the cummins be a lot heavier than my I-6 mercruiser or a 6.5 TD?
The 4.2 liter, is that the BT4?
 

JoLin

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I'm curious as to why one would want to go this route? For a recreational boater the payback in fuel savings doesn't make up for the cost of the conversion.
 

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I'm curious as to why one would want to go this route? For a recreational boater the payback in fuel savings doesn't make up for the cost of the conversion.

It's not just fuel economy that I'm after. It's also reliability and decent power without adding too much extra weight.
Removing the I/O and repowering with a pair of 4 stroke outboards would be the ideal but it's not in my budget.
I'm on the east side on Vancouver Island.
My boating will mostly be in the narrows and although we don't see big seas on this side we do get some very nasty tidal currents that can get you into trouble real fast if you loose power.
 

smokeonthewater

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I don't see diesel being ANY advantage there.... reliability and decent power would be any well maintained engine..... With gas you'll have more power and less weight.

I wanted to install a diesel 1: because at the time my boat had no engine in it, 2: I already had the GM 6.2, and 3 Mostly just for the novelty of it IE 'the cool factor' ... I had happened across a set of manifolds cheap and that got me thinking... by the time I finished thinking (about an hour) the manifolds were sold... then I got to searching and realized I could put a good gas engine in for less than the cost of the diesel manifolds lol.
 

JoLin

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It's not just fuel economy that I'm after. It's also reliability and decent power without adding too much extra weight.

Gas is lighter than diesel. Gas produces more power than a normally aspirated diesel of the same displacement. Kevin (smokeonthewater) has it right.

In the end, though, it is of course your boat. Best of luck with whatever you decide.
 

Scott Danforth

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The 4.2 is a V6, and much lighter than your I6, and a 4400 rpm wot if I remember right. They are paired with the bravo drive. The 2.8 4-banger was rated at 120hp. These are joint venture motors sold thru mercriser
 

HT32BSX115

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There is also the 3.0 twin turbo vw marine diesels.
http://www.seapowermarine.co.uk/marine-shop/vw-volkswagen-marine

I had a 6.5L powered GMC Suburban from 1994 (bought it new) until Summer 2014.

Drove it 205,000 miles in those 20+ years. Never really had a problem with it at all. (only had to have it towed once in those 20 years!)

Even turbocharged (NON-aftercooled) , it made less than 200hp.

I always though a Peninsular Diesel engine would run nice in my current boat (7.4L+ Bravo III) since it would be rated at literally the same prop HP.

Don't think it would be very cost effective. I could probably replace the current 454 AND buy years of gasoline for the difference in cost.

That V-8 VW diesel looks good though (if money is not a factor!)

[h=1]Mercury? Diesel
4.2L (Tier 3)[/h] Smooth and Powerful
This Mercury Diesel engine sets a new benchmark for low noise and vibration.
  • Power mhp / kW 370 / 272
  • Maximum RPM (WOT) 4200
  • Engine type V-8
  • Displacement (L) 4.2
  • Weight (engine only) 836 lbs / 379 kg

I don't think it would be cheap......
 
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