Outboard powered

[34Clipper]

Ever seen a marine trader (clipper here in Australia) extended and converted to outboard motors? Now you have!

CHB/https://www.boatsonline.com.au/boats-for-sale/used/power-boats/clipper-34-flybridge-outstanding-condition-swaps/307234

 

[Davil1]

any idea on power?
picture seem to be on the 70hp's?

 

[HeadedToTexas]

Crikey! I've read and heard about such conversions, but that's the first pictures I've seen of a an outboard refit on a trawler. Fascinating. Think of the storage space you'd gain without that big diesel in the engine room?

 

[CharlieO.]

any idea on power?
picture seem to be on the 70hp's?

It states twin 60's to replace to the 120 hp single diesel. I am surprised they said the conversion uses less fuel than the original engine.

 

[O C Diver]

I find it hard to believe that it burns less fuel. Typically the 60 HP outboards have significantly smaller propellers than what would have been original with the diesel engine. That would be equivalent to pushing a work barge with outboards, better turning ability but lots of slippage going forward. Wonder what speed it cruises at? If you could find an outboard motor manufacturer with a much taller lower unit gear ratio that could swing an 18 to 20" propeller, you might have something significantly improved.

On the plus side, you could have a very nice wine cellar or maybe another hundred gallons of fresh water with the extra space.

Ted

 

[Keysdisease]

Good choice of power. The Yamaha 4 stroke hi-thrust motors should serve that installation very nicely. I had a pair of 9.9 hi-thrust Yamaha's on a 36ft sailing catamaran and they worked great.
With an regular o/b on a sailboat, you put the engine in gear, throttle up, then mosey to the cooler, grab a refreshing beverage, take a long drink, and then the boat starts to move.
On the Cat w the hi thrust motors, I throttled up while holding a shroud, because it jumped when it got juice

 

[heysteve]

It seems like it would result in a significant change in the CG and not for the better in sporty conditions. However, it'd probably be WAY quieter in the salon underway and the idea of a basement does have a certain appeal

 

[rslifkin]

The high thrust Yamahas do have bigger props and lower gearing than the regular outboards of comparable power. I'd still expect twin 60s to have less prop than the original setup, although it might not be dramatically less. Between that and the move to gas engines, I'm also quite surprised it burns less fuel.

 

[DavidM]

Modern outboards produce 12 hp per gph of gas. Older diesels like the Lehman 120 that normally comes with that boat produce 16 hp per gph of diesel. Modern common rail engines produce as much as 20 hp per gph.

David

 

[boomerang]

The high thrust Yamahas do have bigger props and lower gearing than the regular outboards of comparable power. I'd still expect twin 60s to have less prop than the original setup, although it might not be dramatically less. Between that and the move to gas engines, I'm also quite surprised it burns less fuel.

I cannot believe that anyone is doubting the specs quoted by a yacht broker! Gee wiz...it's not like they'd outright tell an untruth just to make a sale...

 

[Comodave]

Interesting idea, but I would have a couple of concerns. In rough water would the outboard props break the surface and be exposed to air? Since they have converted from diesel to gas did they replace the electrical appliances with ignition protected ones? It actually looks better than I envisioned before seeing the photos.

 

[rslifkin]

Since they have converted from diesel to gas did they replace the electrical appliances with ignition protected ones?

Technically that would only be necessary in spaces that contain fuel tanks or lines, being that the engines are outboard. Any equipment that's separated from the fuel tank / line space wouldn't require ignition protection.

 

[ofer]

Last season I hung the Honda power thrust 60 HP on my swim step.

it's used for emergencies as needed.

I was pleasantly surprised that it moves my 50' wood boat at 5.5kts.

 

[Comodave]

Technically that would only be necessary in spaces that contain fuel tanks or lines, being that the engines are outboard. Any equipment that's separated from the fuel tank / line space wouldn't require ignition protection.

That is exactly what I was referring to.

 

[BruceK]

Ever seen a marine trader (clipper here in Australia) extended and converted to outboard motors? Now you have!

CHB/https://www.boatsonline.com.au/boat...-flybridge-outstanding-condition-swaps/307234

Not pretty, but practical. Here in Sydney`s Broken Bay/Hawkesbury region there are several charter/hire boats organizations usually renting outboard powered houseboats, renting eg. a Mariner 34s, with twin outboards replacing the inboards. Presumably it`s way cheaper than replacing the diesels, servicing is cheaper, and fits their outboard power ethos.

 

[Southern Boater]

Ever seen a marine trader (clipper here in Australia) extended and converted to outboard motors? Now you have!

CHB/https://www.boatsonline.com.au/boats-for-sale/used/power-boats/clipper-34-flybridge-outstanding-condition-swaps/307234

The original Clipper 34, either aft cabin or sedan, was a local icon of the Hawkesbury River in the late 70’s and 80’s, but this is just the Clipper 30 with a pod extension. A bit cheeky calling it a 34.
No doubt just setup up for river and lake cruising as a houseboat, certainly not going to sea.
These variants suffered badly from cabin/house and deck rot as well as the usual osmosis.

 

[RT Firefly]

Greetings,
Yep. Easier and cheaper to re-power and if and when diesel outboards become popular (and prices of same go down), probably a much more viable option than diesel inboard(s).


I imagine the trim imbalances can be readily adjusted with careful re-organization of the, now, massive ER space. Might even be room for an extra bunk.

 

[Mambo42]

It is an idea, but am wondering how the loss of weight is compensated. Both the engine and the diesel tanks did have an important role in the stability of this vessel. No idea what they did with the fuel tanks, but there could easily be a 2000 kg shift in balast on this vessel.
And sincerely hope this vessel is not carrying 1000 or 1500 liters of gasoline now. First of all gasoline is much more expensive, but I would not want to have the risk of fumes onboard.
This boat is perhaps nice for day tours on calm water, but I would not want to go out with this boat in the Aegean sea.

 

[Southern Boater]

Greetings,
I imagine the trim imbalances can be readily adjusted with careful re-organization of the, now, massive ER space. Might even be room for an extra bunk.

A massive water tank would be a good start

 

[Southern Boater]

It is an idea, but am wondering how the loss of weight is compensated. Both the engine and the diesel tanks did have an important role in the stability of this vessel. No idea what they did with the fuel tanks, but there could easily be a 2000 kg shift in balast on this vessel.
And sincerely hope this vessel is not carrying 1000 or 1500 liters of gasoline now. First of all gasoline is much more expensive, but I would not want to have the risk of fumes onboard.
This boat is perhaps nice for day tours on calm water, but I would not want to go out with this boat in the Aegean sea.

The doesn’t say what fuel capacity is, only water at 440, but maybe only a few hundred in fuel?
She would bounce around like a cork in open water I would think, but fine for river and sheltered water.
Somebody has spent quite a bit on the conversion though, the engine pod/extension, cockpit and flybridge hardtop, solar and no doubt at least hull painting to blend in the fake planking look on the topsides into the pod. The inside looks pretty original

 

[Portage_Bay]

The risk of carrying a large capacity of gasoline for cruising is a risk I would not accept.

Managing the weight change shouldn't be too hard. The outboards could be supported by a pod with sufficient volume to carry their weight.

Managing the missing weight of the engine, transmission, shaft and misc equipment can be done with ballast. Trading potable water for sea water as the potable is consumed. To illustrate I'll assume the boat was built with a single Ford Lehman 130 or similar.

With apologies to the rest of the world that uses the metric system

1120 lbs engine weight
150 lbs transmission
100 lbs shaft
300 lbs starting battery and other stuff
1670 lbs total

8.34 lbs gal potable water
200 gal water required

Two tanks needed, potable starts out full, sea water ballast empty. Manage tank levels as needed. You wouldn't need to mess with it until the original potable tank(s) are emptied.

Or because outboards do not support large high output alternators a fully silenced generator, even easier with gasoline engines, and a massive battery bank.

The weight added up top could be compensated for with fixed ballast.

In the for what it's worth column I spent some time on a commercial gill net boat that had been converted from fishing to wildlife research. The inboard diesel replaced with outboards on a pod and the house had been extended. The boat performed very well. It's all manageable with attention to weight and where it is placed.

 

[rgano]

Extra water tankage (seawater and/or fresh) would be a good start for ballast here. Maybe some ballasting has been done, and we just don't have the info.

 

[Benthic2]

I would think using water for ballast would be a bad idea. You are trying to replace steel. If you replace it with something less dense, your ballast tanks will take up more room than the engines did, cancelling out the benefit of an empty engine room. I'd go with lead as low as you can get it.

 

[rslifkin]

I would think using water for ballast would be a bad idea. You are trying to replace steel. If you replace it with something less dense, your ballast tanks will take up more room than the engines did, cancelling out the benefit of an empty engine room. I'd go with lead as low as you can get it.

Agreed. And if you can get the ballast low enough, you won't need the entire weight of the old engines to replace them stability-wise, leaving some wiggle room to add weight in the form of extra water tanks, etc.

 

[RT Firefly]

Greetings,
Problem, as I see it with installing water tanks for ballast is, as the water is used up, your trim changes AND if the extra tanks are partially filled, the free surface effect will come into play if not well baffled.


Appropriately ballasted and fitted with diesel outboard(s) might be a viable conversion IMO. One would eliminate potential dangers of gasoline and negate any problems of carrying dual fuel IF fitted with a diesel generator.


Edit: Just found this: https://newatlas.com/yanmar-dtorque-111-turbo-diesel-50hp-outboard/51675/

 

[rgano]

Agreed. And if you can get the ballast low enough, you won't need the entire weight of the old engines to replace them stability-wise, leaving some wiggle room to add weight in the form of extra water tanks, etc.

I agree up to a point. The water tanks would be able to be placed uniformly lower than the metal engines and if fresh water, Hollywood showers for all when in safe waters. A certain amount of lead is probably called for as well, but I still like the idea of some extra water.... or wine, as the situation calls for. I remember when a French destroyer visited Norfolk Naval Station and our ship's officers got a tour. where their wine tank was pointed out.

 

[Portage_Bay]

I call this kind of exercise "fun with numbers" Fun to figure out, I'd never do it. I don't like outboards and gasoline for serious cruising.

True solid steel is more dense than water. However an engine is not solid steel. And an engine has fittings that stick out beyond the block making the space between say the alternator and the block not usable by anything else other than wires and hoses needed for the engine. The FL 135 with transmission in inches is 63.16" length overall, 32.48" pan to header tank and 25.24" width overall (Lehaman Spec Sheet) A tank that size holds 224 gal would fit in that area. My rough calcs above indicate 200 gal is needed. I haven't allowed for the mass of the tanks themselves so a bit less is required.

I did speculate using two tanks so that sea water ballast can be taken on as potable water is consumed. That does then require a total width of 50.48" Maybe that could work, maybe not. The twin tanks will take up more engine room volume than the engine but you don't need to work on the tanks. You just need to get past them to access other equipment. The magenta outlines approximate width of the tanks in end view.

I would think using water for ballast would be a bad idea. You are trying to replace steel. If you replace it with something less dense, your ballast tanks will take up more room than the engines did, cancelling out the benefit of an empty engine room. I'd go with lead as low as you can get it.

 

[Portage_Bay]

I see some potential advantages to re-powering an older boat with outboards.

• The engine noise is outside the boat
• Interior volume for living, storage and tankage could increase
• Cost "might" be less

Disadvantages

• Swim step is less functional or not usable at all
• LOA is increased
• No ability to run large frame alternators to charge big house bank

For a newer boat I don't see any advantages. I do see a significant potential disadvantage. Service life of the engine(s). I just don't see any outboard, gasoline or diesel, lasting as long as an inboard diesel.

 

[Max1]

Interesting but not for me.

Twin 60 HP gasoline outboards instead of my single 1970's Lehman Diesel?
Two gasoline outboards have "Better fuel consumption" you say?.... Yeah, right.
No thanks.

 

[DavidM]

Fore aft balance might be the same with the lighter outboards sitting way aft on a pod. Total weight can be compensated with iron/concrete ballast but for cruising in protected waters, probably is not needed. Will pick up a little speed with less displacement.

David