38’ northern bay stretched to a 41’

[cb34]

Volvo D13 would be my choice for your application.
Dealer and service availabilty is important.
A lot of people say Volvos are expensive to own but I rarely hear about them needing work so there is that. Maintain it and get good value along with a big dealer network.
Compact and light making HP where you want it.
Good luck with your build.

Great engine but not common rail = higher db's running

 

[Keelboater]

I agree with post #14 by tunaorlater. Core it. I would look into foam core and avoid balsa core. That's just my opinion. Balsa is very strong but the new foam core materials do not soak up water like balsa can. In a perfect world, that balsa should remain perfectly dry forever, with little to no worries. Then one day unskilled labor begins drilling holes in it for mounting accessories and the rest is history. That has to be the #1 reason balsa cored boats get a bad reputation for being wet.

 

[JimRP31]

subscribed

 

[c1steve]

If it was my boat, I would use Corecell M80 on the sides, and probably M100 on the bottom. Balsa has many strength advantages, but if it does get wet the core can rot in that area. Also it is significantly heavier than Corecell.

For an engine I would pick the Scania DI13. I have not found Volvo to be particularly well engineered, and parts prices are terrible. IMO, Volvo looks at customers as stupid cash cows, who do not know they are being reamed over and over. On average I have found Cummins to be far more reliable over time than Volvo. Cat somewhat more reliable. Scania has a super reputation, but I have no personal experience with them. I was a boat mechanic and shop owner for 20 years.

However I have no experience with the Volvo D13, it might be a great engine. Also if you potentially troll in the 2-4 knot range, check into which gearboxes are available. Twin Disc and ZF have electronically controlled trolling valves, with auto kickout if the throttle is increased. If this matters, make sure the D13 transmission can do this.

 

[c1steve]

The core helps the boat hold it's shape in a seaway, which well make it faster. Possibly use stitched fabrics instead of woven, so less resin is used. That might save 1,000 lbs. Also if the manufacturer uses all vinylester resin, that would increase strength somewhat, so they might be able to reduce the laminate slightly. If you want speed, keep non essentials to a minimum, such as no genset, etc.

 

[Downrigga]

Just my opinion but unless your using the boat for something like lobstering your better off with a cored hull. Faster, stiffer, less stringers, won't shutter in a head sea and won't sweat like a solid core will. If it were me I'd build a composite hull with an Airex core for the bottom and a balsa core for the top. If your looking for speed and reliability the best choice is going to be the Volvo D13. No other motor in this class will perform as well. Look at fuel curves, look at torgue curves. Anyone saying the Volvo D13 is poorly engineered has some homework to do. That comment is simply not true. Your going to want low end torgue and you will get that with a Volvo. It's a bullet proof motor proven over and over again. World wide market share. ts one of the most produced diesel engines in the world. They sell 120,000 per year. Service anywhere, parts guarantee in 3 days, excellent power to weight ratio and less turbos to deal with than some others in that higher hp range. There is a reason why Volvo has so much market share and why they meet tier rating requirements way ahead of other manufacturers. Your boat will fly with this combo. Your going to want lifting rails. They will improve fuel economy, ride, and speed. They need to be put in the correct location. Some do not have a good understanding of where that placement should be but there is a sweet spot so do your homework. A few have been stretched to a 41. No Issues. Great riding fast hull that performes well in both a head and following sea. If you really waant to get fancy, dovetail the bottom of the hull with the extension. You will love the way it rides. Good luck with your build.

 

[Downrigga]

I’m interested in hearing from you about why your on the side of solid glass hull. Any information or why it’s you prefer? I wouldn’t mind a heavier boat. no Replacement for displacement and even if the core is stronger I’m not convinced it needs to be stronger then solid fiberglass hull. I do see lots of antique hulls out there and I have no concerns with my finisher. I don’t know him personally but nothing but good stuff from salty boaters I’m hearing.

It's a misconception that a cored hull is lighter than a solid glass hull. It can be heavier depending on the lay up.

 

[Tenacity]

FPT C16 1000hp gets my vote. Great marinization, very fuel efficient for it's output, bedplate engine, etc. They are rugged and great performing engines and for a 16l, smooth and quiet.

 

[Giamarie rose]

Question for anyone who thinks they have good knowledge on engine and transmission pushing a 41’er. Looking at purchasing 750 John Deere with a 2:1 gear ratio. thoughts on that configuration? Should I be using 1.75? Can I make up for anything lacking with pitch and prop?

 

[xbskt]

Question for anyone who thinks they have good knowledge on engine and transmission pushing a 41’er. Looking at purchasing 750 John Deere with a 2:1 gear ratio. thoughts on that configuration? Should I be using 1.75? Can I make up for anything lacking with pitch and prop?

What is WOT on that motor?

 

[tunaorlater]

What is WOT on that motor?

2200

 

[Downrigga]

Question for anyone who thinks they have good knowledge on engine and transmission pushing a 41’er. Looking at purchasing 750 John Deere with a 2:1 gear ratio. thoughts on that configuration? Should I be using 1.75? Can I make up for anything lacking with pitch and prop?

You said speed was super important to you. Why not looking at more HP? The John Deere is a good motor though.

 

[Giamarie rose]

You said speed was super important to you. Why not looking at more HP?

Found a good deal on this engine and transmission.

 

[Downrigga]

Found a good deal on this engine and transmission. The deal is very good and that won’t do it unless I think I can get 22knots

You will get a lot more than a 22 knot cruise going with a different engine. Keep that in mind. Also until you talk to the other engine manufacturers you won't know which is the better deal. Make sure you compare performance curves. Every one of these motors will give you a different result in the end. Usually deals are not as good as you think when you start comparing. You often get what you paid for. Remember the three speeds. The speed they tell you before the build, the speed they get during the sea trial, and the speed you get after its outfitted. That is the only one that matters. You picked one of the two fastest hulls you can get today. If speed is super important you got the right hull to give you tons of speed if you select the right motor.

 

[Giamarie rose]

You will get a lot more than a 22 knot cruise going with a different engine. Keep that in mind. Also until you talk to the other engine manufacturers you won't know which is the better deal. Make sure you compare performance curves. Every one of these motors will give you a different result in the end. Usually deals are not as good as you think when you start comparing. You often get what you paid for. Remember the three speeds. The speed they tell you before the build, the speed they get during the sea trial, and the speed you get after its outfitted. That is the only one that matters. You picked one of the two fastest hulls you can get today. If speed is super important you got the right hull to give you tons of speed if you select the right motor.

Thank you for responding and being honest. Got a quote for 900 scania, 800 Volvo and prices were identical with everything needed. Waiting on a few more quotes then I’m purchasing

 

[Downrigga]

As far as trany ratio goes. Pay Mike a few bucks to get his boat on a travel lift with canyon weight. You will be able to dial your trany and prop right in. Maybe he already knows. The other consideration is balance. Your builder should be able to help you there.

 

[Kiteboy]

Where will the boat be out of, and is it for canyon/bft fishing?

I dont know much about engines, but if i was building a big NB/MB I would defiantly be considering an mtu or MAN. Speed is important imo.

These are some engine room pictures from a speed daemon 38’ NB with a 1200 MAN

 

[Downrigga]

The problem with Mann is the dealership network for getting service is lacking so you pay big bucks before they even step on your boat because of the travel distance. The other thing is they are crazy expensive to work on. Especially the new ones with the 3 turbos. 44k just to change a rear main seal. Thats nuts. Brads boat is the ultimate rocket ship though.

 

[Keelboater]

A 38 NB makes a nice MAN cave. (Or any other kind of cave for that matter)

 

[Frank Grimes]

The problem with Mann is the dealership network for getting service is lacking so you pay big bucks before they even step on your boat because of the travel distance. The other thing is they are crazy expensive to work on. Especially the new ones with the 3 turbos. 44k just to change a rear main seal. Thats nuts. Brads boat is the ultimate rocket ship though.

I think there's one shop that splits time between Maine and the Cape that specializes in MAN. And they are buuuusssssssy. Seems that the newer gen MAN engines have been more reliable, the big SF captains that run MAN boats love 'em (they also don't pay the maintenance bills)