Power / Sailing Multihulls

[beau]

Yesterday I went out in my friends 40ft SAILING catamaran (grainger design)
He has fitted two Steyr 170 hp lightweight diesels.
The weather was 15knots of wind in a short chop.
We cruised at 15 knots directly into the waves.
It was really phenomonal, planning boats were beside us and they were going up and down over the waves and we were going through them.
A fantastic ride and dry.
No bow wave was evident at speed I assume because the hulls were long and narrow, although we did have a large stern wave.
The water was breaking from the stern at approx. ten knots of speed.
Coming home with the wind behind us was even faster however the wind speed had dropped a little.
I think more multihulls should consider larger motors if they have narrow hulls.
My friend now rarely uses sails on short trips.
He fitted the larger motors 10 years ago.
He makes the point that most boats are underpowered.
If you want economy just run at half throttle.

[cat man do]

Originally Posted by beau

Yesterday I went out in my friends 40ft SAILING catamaran (grainger design)
He has fitted two Steyr 170 hp lightweight diesels.
The weather was 15knots of wind in a short chop.
We cruised at 15 knots directly into the waves.
It was really phenomonal, planning boats were beside us and they were going up and down over the waves and we were going through them.
A fantastic ride and dry.

Sounds like a great day Beau, 170hp on 40 sounds rather large

No bow wave was evident at speed I assume because the hulls were long and narrow, although we did have a large stern wave.

Did she feel like she was squatting? (large stern wave). Did she have a bow out that settled back down when power dropped back?

I think more multihulls should consider larger motors if they have narrow hulls.
My friend now rarely uses sails on short trips.
He fitted the larger motors 10 years ago.
He makes the point that most boats are underpowered.
.

Could have saved a lot of money on rig and sails

Also worth noting that the steyrs are very expensive when compared to other brands of engine, another brand would have been even more money saved to purchase fuel with

If you want economy just run at half throttle

I thought diesels liked to work?

[beau]

Sounds like a great day Beau, 170hp on 40 sounds rather large

I think we all thought that, but it works for him. His top speed he told me was 22 knots but I only saw 15 yesterday against a tide of 2 knots.

Did she feel like she was squatting? (large stern wave). Did she have a bow out that settled back down when power dropped back?

There was some squatting, the stern dropped about six inches under way but it wasn't noticable on deck. He did fit bulbs to the bow after launching 13 years ago because the bow sat a bit low in the water at launching.
I was able to look over the bows under way and see the bulbs and they were clearly visible just under the water. At rest the bulbs are 6 inches under the water.There was no visible bow wave and no trough along the hull. The stern wave was similiar to what i have seen on a planning power cat (noosa cat)

Also worth noting that the steyrs are very expensive when compared to other brands of engine, another brand would have been even more money saved to purchase fuel with

I think the Steyrs have the best weight to power relationship and they are reliable. He ran them at 2,000 rev's.

I was very impressed and with the motion control of the boat over/ (through) the swell unlike a pure displacement boat where the motion is dictated by the waves.

My wife was very impressed.

As I have explained earlier I put two 30 hp Honda outboards on my 40 ft aluminium trimaran, I get a maximum 10 knots and cruise at 7.5 knots. I am underpowered, as soon as I get more funds together I am replacing the motors with two 90 hp outboards. Not sure yet whether i will get the new two strokes Tohatsu or Etec Evinrudes or four strokes?

I still strongly support the concept of outboards on a cruising multihull because of the initial lower cost and the fact i can lift them clear when I beach.(which is often)or anchor very shallow (just floating at low tide) This way I can anchor in better protected anchorages and well away from ALL other boats. Plus if you need to repower which I need to do, it does not cost the earth.

I find that the biggest problem with the resale price of diesel powered cruisers is the condition or lack of condition of the motors when you go to buy secondhand. If you buy a dud, it can cost you a LOT of money.

[cat man do]

Any idea what grainger design it is?

Was it the Oasis 38 powersailer, which I believe these may be the moulds for sitting out in the open, unfenced in Yatala?

super butcher - Google Maps

[lancelots]

Steyr's Monoblock Engines Making Waves in US Marine Market by PMarsh

The Austrian engine builder Steyr Motors set up a North American subsidiary in 2006 to market its line of lightweight, high performance diesel engines with a power range from 55 kW/75 hp to 184 kW/250 hp. Steyr was formerly part of the Steyr-Daimler-Puch group and became independent after its 1990 break-up. (Other spin-offs buildSteyr small arms and Steyr tractors.) The name comes from the town of Steyr in Austria, which is a major engineering and manufacturing center.
Engine production at the new Steyr Motorentechnik GmbH is based on the four-stroke "monoblock" diesel design that the company had pioneered in the early 1920s, coupled with modern electronically-controlled fuel injection. The range is based on inline four-cylinder and six-cylinder cores with two valves per cylinder and displacements of 2.13 L and 3.2 L. The displacement per cylinder is 533 cc with a bore of 85 mm, stroke of 94 mm, and compression ration of 18:1. Turbo-charging and charge-air cooling are standard.
Steyr did not invent the monoblock, but was the pioneer in applying it to diesels. The concept was first applied to high-performance gas engines for aircraft and automobiles as early as 1909, when the French Delage was fitted with a 1.4 L version. One of the first "mass-produced" automobiles to use a monoblock gas engine was the V-8 Oldsmobile Viking 1929-30, followed by the Ford V-8 monoblock in 1932. However, the extra cost was not justified for mass-production of cars at a time when gas was cheap and there was no incentive to remove weight from a vehicle.
Steyr has successfully refined its version of the monoblock into a package that delivers power-to-weight ratios close to those of gasoline engines, while maintaining the diesel's reliability and torque. Essentially, the monoblock is an iron-alloy one-piece casting containing the entire overhead valve train, combustion chamber and cylinder in one compact unit with removable crankshaft bearing supports. By eliminating the head bolts and head gasket, the monoblock can be cast with larger and more functional coolant passages, improving heat distribution and greatly reducing deformation and stress in the cylinder head.
This superior coolant path and double-circuit cooling allows the engine to handle maximum speeds of up to 4500 rpm and be rated for continuous duty at 2800 rpm. To handle this level of performance, all elements of the combustion system are high quality: the dynamically-balanced crankshaft is forged chrome-molybdenum steel and the pistons are high-silicone aluminum.
The oil pan is a separate aluminum two-piece casting that is clamped to the lower half of the monoblock by through-bolts at both ends. The pan carries all the attachments and is insulated from the monoblock by a heavy gasket and flexible seals around the crankshaft bearings. This significantly reduces noise and vibration.
The engine's patented fuel-injection system is also notable: a lift pump delivers fuel to a port on the end of the block, where it flows internally to the unit injectors. These are mechanically driven by the overhead camshaft and pressurize the fuel to 2000 bar/28,000 psi. The timing is controlled by a mechanical rack inside the valve cover that is computer /electronically controlled to produce a two-stage injection. This hybrid system features automatic bleed capability and as much as 80% of the fuel is returned to the pump. It allows the engine to meet EPA Tier 2 and can be by-passed in the event of an electronic failure, permitting the use of the default mechanical setting.
Building on the experience gained with the 170 kW/230 hp Steyr 236, the company's engineers initiated a re-design to increase power output. The engine management, injection timing, camshaft-housing and cover as well as piston & piston rings were all upgraded. With a Holset waste-gate turbo-charger, the new model was designated the Steyr 256-developing 184 kW/250 hp. This engine weighs 708 lbs, has a horsepower to weight ratio of 2.73:1. It has the same footprint as a GM small block V-8 and the makers claim it is "the lightest, most compact and most dynamic alternative to gasoline engines."
Optional on all models is Steyr's integrated flywheel generator, which extends the length of the bell housing by 30 mm. The three-phase brushless design uses a permanent magnet with 80% efficiency. The voltage options are 14V or 28V. The system is virtually maintenance free and features a programmable electronic controller and CAN communicaton with engine management.
The Steyr's reliability, fuel economy and high power-density have made it popular with military-vehicle builders throughout Europe/NATO for small tanks, jeeps and personnel carriers. (A standard S 2000 Peacekeeper was listed in the Guinness Book of Records as the world's fastest tank at an average speed of 82.23 kph / 51.10 mph. It is powered by a Steyr 2133 that revs to 5,000 RPM and produces 200 BHP and up to 480 Nm Torque.) Steyr engines are used in commercial vehicles built by Russian and Asian companies.
Steyr has also paid particular attention to the engineering of the marine version, which is in worldwide use on fast rescue boats, small patrol craft and sport-fishing boats, The company offers a unique package approach: it will modify the basic engine in the factory so that is ready to bolt straight on to whatever outdrive or waterjets the customer specifies. For sailing yachts, 75-85 hp Steyr engines can be packaged with the SD 10 Saildrive from ZF Marine-which also has plant in Steyr. This creates a competitive marine diesel power package as an alternative to gasoline engines. Owners report the fuel consumption is excellent at 3 gph per engine and represent a realistic alternative to the typical V-8 big block gas engines.
For 2008, the engine remains the same, but the heat exchangers and piping on top of the block have been re-designed for greater efficiency and given a more integrated contemporary look. The engineers have also capitalized on their experience with the flywheel generator system by adding an entirely new hybrid power option. The hybrid transmission contains an internal electric motor/generator that will allow the engine to efficiently direct-charge a battery bank and then run directly off electric power at 600 amp/hours giving quiet low-speed cruising for a weekend.

[cat man do]

All very nice but where do you get them serviced?

I can find someone to work on a cummins ,which I have, for this very reason and probably most other breeds of engines worldwide but a steyr?

[lancelots]

STEYR-MOTORS.com

[lancelots]

Beau,

Can you tell me if your friend had straight shafts on his cat or sail drives? I can’t seem to find a reference to sail drives on the Steyr 170 hp. If it was straight shaft I’m just wondering how far forward the motors were. Is he a close enough friend that you could take a few photos of the engine rooms?
I’m intrigued by the bulbs on the bow never heard of that on a sail cat how does it effect performance under sail? Would love to see a photo of them as well, about what size were they?

[Aussiesuede]

I'm very curious as to the engine, tank-age layout. 1100 lbs on the tail end of a narrow hulled 40' seems heavy. Did he move his tanks fwd? Does he have to make sure to keep them partially filled to keep the nose from flying? Any idea of the dry weight and payload capacity? I agree with the desirability of 'overpowering' but he's at DOUBLE what I would have considered enough to handle ANY situation.

THANX!

[beau]

I am out on Moreton bay cruising around for a week but when I get back I will get as much information as possible. The owner is very pround of his setup and will willingly supply any information required.

From what I remember, the motors are in the stern. He added a bulb on the bow which is about 15 inches long and a diamenter of 10 inches. He put it in because the boat was bow down at launch. At rest the bulb is underwater about 12 inches but raises to 3 inches underwater when underway.He has also extended the stern by 2ft with I suppose could be called a swim platform which is underwater by 3 inches at rest but is submerged by 12 inches underway with the water breaking clean after ten knots of speed.
There is no noticable stern squating but there is a significant stern wave.
I will try and get photo's etc when I return.

[beau]

Straight shafts are fitted.

[cat man do]

Originally Posted by lancelots

Beau,


I’m intrigued by the bulbs on the bow never heard of that on a sail cat how does it effect performance under sail? Would love to see a photo of them as well, about what size were they?

Some Crowthers have bulbous bows.

The Cruising Multihull - Google Books

[lancelots]

BEAU your my hero,

I can’t seem to find a reference to sail drives on the Steyr 170 hp? I answered my own question on that one as sail drives max out at 100hp so his would be straight shaft.

If you would mind asking your friend did he have to do much modification (strength wise) to install the new motors?

Does he feel that his diesel engines suffer from not being run the 80% to 90% of full power?

The steyr 170hp weighs about the same as the D2- 55 Volvo Penta 55 Hp exciting stuff
And the power for a lightwave 46 is 2 x D-3 160 Hp Volvo Penta engines.

I’d be pretty impressed if I was him too.

Have fun on the bay!

[beau]

Ok, I have found out a bit more about the grainger 40.
The steryr motors are 165hp not 175 as i reported and they are mounted in the middle of the hulls not at the stern as I reported.

[lancelots]

beau a few photos of the engine rooms would be nice, if you get the chance, or perhaps your very proud friend might like to showcase the boat here?