John Capuano said:
I found a Lugger, smallest I could, for my side engine model L984D power output 70HP. Can't find out if wet or dry liners. Does any one know? Is this the smallest Lugger available?
I believe the L984D is the smallest Lugger propulsion engine available. I can’t find any reference to cylinder liners for the L984D, so I don’t think it has any. Since it is based on a Toyota block as opposed to most of Luggers, which are based on John Deere blocks, I think it is probably a throw-away. If you would prefer cylinder liners, you might consider the Lugger LP445D. The LP445D has wet cylinder liners and it is rated at 85 HP maximum, but the continuous rating is 65 HP @ 2200 RPM. I provided a comparison of the differences between the L984D and the LP445D:
Specifications: L984D LP445D
Bore: 3.85 in (98 mm) 4.19 in (106 mm)
Stroke: 4.5 in (115 mm) 5.0 in (127 mm)
Displacement: 212 cid (3.47 ltr) 276 cid (4.5 ltr)
Length: 46.22 in (1174 mm) 45 in (1143 mm)
Width: 25.15 in (638.7 mm) 24.6 in (625 mm)
Height: 27.27 in (693 mm) 35.3 in (896.3 mm)
Weight: 787 lbs (357 kg) 1070 lbs (485 kg)
With Hurth gear Keel Cooled, without gear
Continuous Duty: 64 HP @ 2200 rpm 65 HP @ 2200 rpm
Low speed ~29 HP @ 1000 rpm ~29 HP @ 1000 rpm
As you can see the LP445D has 30% higher displacement and 36% higher weight (without gear-box), but the power is about equal and longevity should be better.
John Capuano said:
Lastly, if I understand Portager correctly, my gen would be run from a PTO shaft off my engines.
Close, but on the L984D & LP445D, the PTO power level is limited to 5 HP, which would only power ~2.5 KW generator. What I’m recommending is a large hydraulic pump coupled directly to the main shaft of the auxiliary.
On the main engine, the pump could either be located between the engine and the reduction gears (note with a controllable pitch propeller you do not need a reversing gear) or between the gear-box and the main propeller shaft. Either way, this requires a pump/motor with “drive-through” shaft. Putting the hydraulic pump between the engine and the gear-box allows it to operate at higher RPM and therefore requires lower displacement. Additionally, the pump/motor on the auxiliary and the one on the main can be identical, which means interchangeable parts and fewer on-board spares. When the main engine is running, the pump can provide sufficient power to run all the hydraulic systems.
John Capuano said:
Does that mean that the gen will only recharge my batteries when the engines are running?
I’m not sure I understand this question. A conventional generator has an engine coupled directly to a generator. The generator does not produce power unless this engine is running. With the system that I’m proposing, the generator can produce power when either engine is running. If you’re referring charging to the engine starter batteries, I plan to keep a separate alternator and battery to operate the starter. Why mess with success?
John Capuano said:
Can a gen be both a PTO driven and have it's own internal engine to make it run if both engines are down? I know this may seem silly, but the more layers of back-up the better as far as I'am concerned.
Redundancy is a good thing, but only if applied intelligently. The classic example is the twin engine aircraft, if it can’t take off on a single engine (and most can’t), then having the second engine only makes it more likely to have catastrophic engine problems on take-off.
The simple answer to your question is yes, you could have an additional engine that is connected by an electric clutch or even another hydraulic pump, but the real question is would that give you the additional security that you desire? That answer is not really, because your fixing the wrong problem.
The truth is having two separate engines fail due to independent causes is extremely improbable. It is the common causes that you need to worry about. On Diesel engines, the most common cause of engine failure is bad fuel and if you feed your engines from a common tank, or buy all your fuel at the same place, or transfer fuel from one tank to the other, well you get the point. The common denominator for the hydraulic systems is the hydraulics. Hydraulic systems are intrinsically very durable, but a leak can allow the critical fluid to escape and shut the whole system down. It is important to have isolation valves to shut off branches that develop problems. It is also important to have spares onboard and enough hydraulic fluid to refill the system once or twice, but the same is true for any drive approach.
Regards;
Mike Schooley