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Old 05-22-2017, 06:09 PM   #1
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Default Mid 90's 2700 - which engines are best? Twin v6 or single 454

I'm SURE this has been asked before, however the search ignores "4.3" and "7.4" soooo....

Looking at getting an SCR. Found one locally with twin v6's. I like the idea that there is an additional engine if one craps out, however - which setup is best for a boat this size? Not looking for all out speed, I have PWC's for that. I'd like something that gets on plane and cruises nicely without sucking down fuel. I also don't want sluggish. I want my first Maxum to be a great experience.

Will typically just be myself and the wife, with the occasional outing including a few friends. Boat has generator and HVAC.
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Old 05-22-2017, 09:42 PM   #2
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In a 27 foot boat I would prefer the single 7.4 for several reasons.

Fuel economy, the 7.4 will burn 12 gph vs 16 gph of the combined 4.3's while giving about the same speed.

Easier to work on only having one engine in a boat of this beam.

Cheaper to maintance one engine and drive.

The twins do make docking easier.

The 7.4 is probably coupled to a Bravo 3 and of the vintage you need to check for corrosion as these had issues.
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Old 05-23-2017, 02:06 AM   #3
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My previous boat was 1997 2700 SCR with a 7.4L/BII and it had plenty of get-up-and-go. My current boat is a 2003 3100 SCR with twin 5.0L/BIIIs and I really like the twins when maneuvering, but I don't like 2X the cost for maintenance. In a 2700 SCR I would prefer a single 7.4L, but things like overall condition of the boat, the number hours and whether it has spent most of its time in salt or fresh water could steer me to the boat with twin 4.3Ls if it is the nicer of the two.
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Old 05-23-2017, 12:58 PM   #4
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IIRC the 2700 has a 8'6" beam. This will make twins very, very cramped in the engine compartment. However, maneuvering with twins is much, much easier. As for redundancy due to an engine failure....A towing package will fix that. You're not going to run on one engine much faster than the speed of being towed. Unless you are in a very rural area, or a small freshwater lake, Seatow and Boat US are almost everywhere.

The cost to repower a single 7.4 will be about the same as repowering 2 4.6's. since the 7.4 take almost 9 quarts of oil, I'm not sure you're saving in oil changes. 1 extra set of belts, and 4 extra spark plugs. for tune ups.

I didn't see such significant fuel savings with a 7.4 (later upgraded to an 8.1). I burned about the same as my buddy with twin 5.0's. Maybe just a hair less.
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Old 05-23-2017, 01:46 PM   #5
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I think the beam is 9'6" actually, so an extra foot. However the context of your post resonates with me.

Thanks all for the input.
Seems like they both have plusses and minuses. Right now the only local 27 SCR is a dual 4.3. I might go look at it this weekend. They are asking $12.5K loaded with arch, heat, AC, generator, and dual engines. If it's not all that, I'll keep looking and perhaps a 7.4 will show up.
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Old 05-23-2017, 04:02 PM   #6
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Quote:
Originally Posted by shrew View Post
IIRC the 2700 has a 8'6" beam. This will make twins very, very cramped in the engine compartment. However, maneuvering with twins is much, much easier. As for redundancy due to an engine failure....A towing package will fix that. You're not going to run on one engine much faster than the speed of being towed. Unless you are in a very rural area, or a small freshwater lake, Seatow and Boat US are almost everywhere.

The cost to repower a single 7.4 will be about the same as repowering 2 4.6's. since the 7.4 take almost 9 quarts of oil, I'm not sure you're saving in oil changes. 1 extra set of belts, and 4 extra spark plugs. for tune ups.

I didn't see such significant fuel savings with a 7.4 (later upgraded to an 8.1). I burned about the same as my buddy with twin 5.0's. Maybe just a hair less.
"The cost to repower a single 7.4 will be about the same as repowering 2 4.6's. since the 7.4 take almost 9 quarts of oil, I'm not sure you're saving in oil changes."

??Repower vs oil changes"??
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Old 05-24-2017, 02:26 PM   #7
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Quote:
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"The cost to repower a single 7.4 will be about the same as repowering 2 4.6's. since the 7.4 take almost 9 quarts of oil, I'm not sure you're saving in oil changes."

??Repower vs oil changes"??
OK, so I seem to keep typo'ing the 6, when I'm shooting for the three. So that should be 4.3, not 4.6.

There is punctuation in there, despite me missing the capitalization of 'Since' in the subsequent sentence. It was meant to be two separate thoughts.

1) The cost to re-power a single 7.4 will be about the same as re-powering 2 4.3's. (Maybe more accurate if going with an 8.1 or an 8.2).

2) since the 7.4 take almost 9 quarts of oil, I'm not sure you're saving in oil changes." (4.3 takes 4.5 quarts)

So for maintenance, around the same for oil changes, twins will use 4 extra plugs and 1 extra set of belts. To me, this really refutes the idea that twins are really twice the maintenance cost. Technically, the other item which would double the cost is the cost of new manifolds and risers.

Apologies for the confusion. Just one person's opinion.
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Old 05-24-2017, 04:08 PM   #8
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Quote:
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OK, so I seem to keep typo'ing the 6, when I'm shooting for the three. So that should be 4.3, not 4.6.

There is punctuation in there, despite me missing the capitalization of 'Since' in the subsequent sentence. It was meant to be two separate thoughts.

1) The cost to re-power a single 7.4 will be about the same as re-powering 2 4.3's. (Maybe more accurate if going with an 8.1 or an 8.2).

2) since the 7.4 take almost 9 quarts of oil, I'm not sure you're saving in oil changes." (4.3 takes 4.5 quarts)

So for maintenance, around the same for oil changes, twins will use 4 extra plugs and 1 extra set of belts. To me, this really refutes the idea that twins are really twice the maintenance cost. Technically, the other item which would double the cost is the cost of new manifolds and risers.

Apologies for the confusion. Just one person's opinion.
Basically I agree with you however in addition to the 6's have double the exhaust to replace there is also a second outdrive and transom assembly maintenance. Ok a Bravo hold over 2X the lube of an Alpha so I'll give you that.

So materials may be a wash but if paying a mechanic the labor will be more for the 6's, most places charge per engine.
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