Sticker shock on marine generators

[wingssail]

Originally Posted by Culwatty

I am actually planning to fit a generator head behind the engine and drive it off a modified front pulley similar to the supercharger belts on an electronic clutch. 10kva head with avr £400 is on ebay, can make the rest myself (could even use timing belts from a car and associated pulleys,

Well thats another idea added to my list thanks you just saved me a few bucks!

I think this might make sense, but you can accomplish the same thing with a large frame alternator and modified brackets and dual belts or cogged belt or sepentine but be careful about exceeding the recommended limit for loads on the front of the crankshaft on some motors, example yanmar.

[waterman46]

Originally Posted by Cheechako

Ever heard of the Atomic 4? or... damn near every SeaRay and Bayliner on the planet? :>)

Maybe tens of thousands Atomic 4s out there operating many years. Had one in my Cal 29 and did 4 LA to SF tough upwind trips plus much more. But I was so glad to get my next boat with a diesel engine and stop the constant worry about gasoline hazards. I would never have gasoline below decks now.
But for the occasional cruiser, a Honda on deck is probably the best choice if budget is limited. A portable, foldable sound screen around it will cut out much of the higher frequency noise and be much appreciated by others in a tight anchorage.

[Mike Banks]

It is the word MARINE.

It is the most adjective there is. Sometimes the Marine and General Purpose Heavy Duty models are identical.

[Rohan]

Originally Posted by MJH

You never mentioned what that upcoming plan was so answers here won't help you much. Perhaps you need to rethink it. I got rid of my genset and went solar.

~ ~ _/) ~ ~ MJH

Mostly for air conditioning while at anchor (which I can't do with solar panels) and as an alternate method to charge the batteries. I am also installing solar.

[Uncle Bob]

Originally Posted by Mike Banks

It is the word MARINE.

It is the most adjective there is. Sometimes the Marine and General Purpose Heavy Duty models are identical.

Mike, I have to agree that the word marine in the description usually "advances" the price point but the two linked gen sets are vastly different, so much so that any price comparison is moot.

[ewishki]

Originally Posted by rslifkin

A good marine generator is also typically a much higher quality unit than a cheap portable one. More in line with a good fixed-mount land based generator. So beefier, more durable, lower RPM engine, better generator head, better voltage regulation, etc. Plus the marine components for cooling and exhaust.

My company sells land based generators into the construction markets and home back up generators and they are no where near the price of marine systems. It isn't a quality thing, they are literally just gouging because they can, imo.

[jbinbi]

I don't know if my fear is unfounded, but I will not run my Honda whilec asleep. Even if it is on the stern sugar scoop at mooring or anchor. The boat SHOULD be pointing into the wind and the exhaust SHOULD go back away from the boat, but if something changes, this is one of those things you don't ever wake up from!

So a no go for to run AC all night.

But maybe I am being overly cautious.

[ewishki]

Originally Posted by wingssail

There are trade-offs for each solution.

For us the choices were:

1. Diesel genset: high reliability of the basic diesel engine and electric head VS cost, complexity of the installation, weight, space, and reports of maintenance issues. We couldn't imagine doing this on our 43' boat.

2. Portable genset (like a Honda 2000): High reliability, simple installation, cheap to purchase and run, and easily replaceable VS space for it, weight added to the boat, and noise, and need for another fuel on board. We tried one (Honda 1000) and found it noisy and it wouldn't run our battery charger at full power.

3. Large capacity Alternator on the main engine: simple, quiet (compared to portable) least weight, no additional fuel needed to be carried VS theoretical additional wear on the main engine, We chose this option as it suited our priority on light and simple, however we have had frequent issues with alternator and regulator life. We carry plenty of spares.

4: Acres of solar panels. Free power and mostly problem free, not too expensive, quiet VS the impact of putting the equivalent of a helicopter landing pad on your boat and the weight of that and the impact aerodynamically on sailing performance, as well as visually. Plus, it only works when the sun is shining. You'll need a big battery and inverter.

Of course we do have solar, but limited (270watts) and a good inverter to run AC appliances when the engine is off.

One might question our choice in light of the recent oil pressure problems on our engine, meaning we might have worn it out charging the batteries, but with 6600 hours on the engine (over 6000 from charging alone) we now have determined that our oil pressure is still actually very good and we see no indication of further problems with the engine. I think our choice has been validated based on our priorities. I would do it again.

From what i have seen, most of the primary engines are cheaper than a genset anyway. So even if you had to replace the motor you are still up money on top of the other benefits of no genset.

[sailorphil9]

Many solutions to the OP question. I bought a used trailer generator, 8 kva, 3 cyl kubota diesel as I wanted to run a heavy welder. I cut it out of the trailer, built a mountng frame. The D722 engine is used in Beta marine engines so I bought the parts to marinise it, plus waterlock etc. I kept the fan to force air over the alt head in the bilge; kept the control panel too. So, I now have a proper marine diesel driven genset (albeit aircooled alternator but no problem there). Dual voltage 120/240 V. Installed under my saloon floor for easy maintenance. Worked fine for 15+ years. Now needs a rewind due to recent water leak :-(



So, if you have access to the skills there are ways to solve the problem at a more palatable cost.

[mvweebles]

The large marine generator manufacturers (Onan, Kohler, Northern Lights) have spent many years perfecting their products. They are extremely reliable often going well over 10,000 hours with little more than scheduled maintenance. They are extremely quiet which is not an easy feat for a diesel engine and involves more than just a sound shield but includes modified air intake as well as below water exhaust . The quality of the output energy is extremely consistent. Put this together in a package that is stuffed into the corner with all maintenance points on a single side, and it starts to become a bit more apparent these are highly engineered pieces of equipment.

Not everyone needs or can cost-justify or space-justify a generator. Running AC at anchor/night is, by far, the one remaining use-case for a generator and is borderline necessity in places like Florida. From there the decision is either a high quality/low-rpm marine generator or a compact lightweight generator with spotty reliability records. If use is intermittent, there are workarouonds such as a 12vdc alternator off the main engine, or some sort of Honda with gas cans and extension cords. But if you want quality, reliability, and quiet, and have the space, there option reduces to one of the major manufacturers such as Onan, Kohler, and Northern Lights. Within that tier, there is plenty of competition to keep the price competitive so I don't buy the inference that "marine" is code for gouging.

As far as tee-ing off an existing thru hull for the generator intake, it is possible but not recommended. That said, Groco makes a handy manifold that comes in a few different sizes (link below). Challenge is you may need to enlarge your existing thru hull to use this so a haul may be needed anyway. Cross sectional sum of the outlets (pi x r ^2) should not exceed the inlet side (thru hull).

https://www.groco.net/products/fitti...water-manifold

I went a similar route but created a seachest that starts with a 2-inch seacock and 2-inch sea strainer to avoid contention. I have a pair of these sea chests, one supplies the generator (amongst other feeds), the other supplies the AC coolant pump which is, by far, the largest raw water intake demand on my boat (Perkins 4.236 has a Jabsco raw water pump with 3/4-inch intake). My goal in using a sea-chest vs multiple single thru hulls was less to avoid holes in my hull (a 2-inch seacock is a big hole) but rather to consolidate valves and thru hulls in a central place within the engine room.

EDIT - BTW, my understanding is Yanmar installation instructions require a dedicated thru-hull. Using a manifold or sea-chest will void the warranty.

[rslifkin]

Originally Posted by sailorphil9

Many solutions to the OP question. I bought a used trailer generator, 8 kva, 3 cyl kubota diesel as I wanted to run a heavy welder. I cut it out of the trailer, built a mountng frame. The D722 engine is used in Beta marine engines so I bought the parts to marinise it, plus waterlock etc. I kept the fan to force air over the alt head in the bilge; kept the control panel too. So, I now have a proper marine diesel driven genset (albeit aircooled alternator but no problem there). Dual voltage 120/240 V. Installed under my saloon floor for easy maintenance. Worked fine for 15+ years. Now needs a rewind due to recent water leak :-(



So, if you have access to the skills there are ways to solve the problem at a more palatable cost.

That's a solid conversion my book. A lot of purpose built marine generators have air cooled alternators anyway, although some newer ones have gone to water cooled for ease of building a good sound shield. My 1980s Onan is a water cooled engine, air cooled gen head (and also a very solid unit).

[capt jgw]

Originally Posted by Mike Banks

It is the word MARINE.

It is the most adjective there is. Sometimes the Marine and General Purpose Heavy Duty models are identical.

AVIATION is worse, but there's not a lot of aviation stuff that's applicable to boats.

[Scott Berg]

10x the cost? Maybe with installation. And expect 10x the life. A good marine diesel genset is good for 10-15k hours. Even the celebrated Honda 2k suitcase genset owes you nothing after 1000 hours... apples and oranges he’s as noted. Home style gensets are for emergencies, marine ones often run full time for weeks on end.

[GinoDelG]

We got rid of our genset and couldn’t be happier. We live aboard full time on a 44 foot sloop and have all the luxuries except maybe aircon, washing machine and freezer.

[a64pilot]

Originally Posted by Cadence

I should think that a radiator cooled diesel genset could have a heat exchanger and raw water pump add. A financial advantage?

Add wet exhaust too, however if you got a Nexgen those mods are easy, and use an electric airconditioner water pump.
On the little Kubota you remove the radiator and bolt the heat exchanger on, wet exhaust is just a different exhaust pipe and like I said use an airconditioner water pump and your done, probably want a sound shield though.

If I could get a good used Nexgen APU for $1,000, I’d do it in a heart beat myself.
http://www.nextgenerationpower.com/semigenapu.html