Inboard Diesel for 30' Trawler

Hello,

I need experienced opinions on appropriate inboard diesel of approx. 60hp for a steel trawler (new construction, displacement hull).

LOA: 30'
Beam: 10.5'
Draft: 3'
Displacement: 14,000 lbs.

The boat will be used on the East Coast of the USA, so servicability and obtaining parts would be of importance.

Thank you.

Tim Gosnell

 

Kubota small diesels are used by many generator manufacturers because of their reliability, size and serviceability. They are also very popular in tractors and forklifts making parts readily available and reasonable.

Yanmar makes very popular and reliable small diesels too, in the 60hp range mostly for sailboats. Their dealer network is very good however oem replacement parts can be pricey, although for a new engine this should not be a problem for quite some time.

There are lots of others out there, these two came quickly to mind.

 

What did the designer specify?

 

I would use a factory re manufactured John Deere , purchased from a JD tractor place , with no core required.

Dry stack, keel cooled so almost no conversion would be required.

Get as many belt drives as you can on the front of the engine.

Second choice would be Deutz , good engines .

Cruising it is most likely that you will need to call for parts for ANY engine so the lowest cost parts makes sense.

Volvo is probably the hardest to find parts for and the most expemsive.

I would avoid any car transplant like a small yannmar (Toyota or BMW) , look at the engine sellers site for a 24/7 operation guide.

IF you have the ability a deep reduction like 3-1 and a larger 3 blade prop may help reduce fuel burn.

 

How about a Detroit Diesel 353. Tough as nails. Easy to get parts for.

 

Thanks guys.

The dealer just specifies the h.p. range.
I have yet to get his study plans. Very preliminary at this point.

The 353 DD may be suitable but may also be a bit more engine than I need.

Will update this post when I know more.

Take care and thanks again.

Tim

 

4-236 Perkins, tough and easy to find parts

 

Thanks Fred. I am going to research the Perkins now.

With a dry exhaust and keel cooling what marinization would still be required? Electrical bonding for corrossion protection etc...?

The extra noise will not be a bother to me and I will spend most time moored or on the hook so neibhoring boats should not be a big issue.

Tim

 

60 sounds large for a boat on the hook unless you also have a dedicated small generator of 5-7 kW. If you do, you may find some parts commonality if both are Kubota based. If you plan on using the main for battery charging, you'd probably be better with a smaller main that can tick along better when charging. I don't know what kind of speed you are after, but I push 18,000 pounds around at an average of about 3.5 hp. I couldn't do that with a 60 HP diesel. If you want the best of both worlds, a turbo diesel is likely the best option. Yanmar used to make a 50hp turbo, but ended production in'99. For a displacement boat, you are looking at 4.5 knots or so. Anything will do that. I'd go with a dedicated genset with any motor over 30hp. If you were going to be docked at a marina with shore power, then it wouldn't be an issue, but for living on the hook, I think tiny is better.

 

Cummins 4BT-cheap, cheaper as reman,dead simple,last decades,rebuild kits are $600...and in the unlikely event you need parts,they are at any and every diesel repair shop any place you will go.

 

The extra noise will not be a bother to me

With a blanket wrap on the exhaust manifold there is no extra engine noise.

If you worry about the noise coming out the stack, look up Hospital Critical silencers and then go find a used unit.

I concur the Cummins 4BT would be a fine engine choice .

One big question is the local Air Police , will you be able to get the boat registered with an older engine ? Tier 1 Tier 2 ?

 

What airpolice are going to come on the boat and check the engine?

 

I'm not up on the US EPA but IIRC when you go to register a newly built boat they may check the engine. But not sure of laws on production vs. home built.

Anyone?

 

Thanks WestVanHan & Fast Fred.

I was thinking of a cruising speed between 5&6 kts.

The boats 28ft. waterline gives a theoretical hull speed of approx. 7kts.

Slowing her down to 5.5kts or so should make for economical operation.

60hp is a good bit of power, well more than needed to drive her at hull speed, but the extra would be good if needed. Then again she needs to be run at a high enough rpm for the diesel to remain happy? The efficiency of a smaller engine would be a great benefit also.

If I could use a high output alternator, dual alternators, or a belt driven generator off the main, I could avoid the having the cost of a dedicated diesel generator and the construction issues associated with it.

Like I mentioned earlier, I am just in the planning stages, and am doing some brain storming.

I appreciate all the good advice, thanks again.

Tim

 

Lots of choices..

FYI as an estimate figure on about 20 HP per gallon per hour. So if you need 40 hp, you'll burn about 2 GPH.