Home |
Search |
Today's Posts |
|
#1
posted to rec.boats.building
|
|||
|
|||
Replacement for Hitachi LR135-31 alternator?
Ray,
You got a couple of good answers so far, but I can not resist muddying the water just a little more. The rating published is often optomistic as referenced to sailboat applications as they seldom run at rated speed and are often charging at the top of the recharge curve so they won't be near the published capability. There is an available 90amp unit that is a bolt-in kit. It will just take some looking as I do not have the part number available. I know of two of these installations that were done by owners. A Yanmar dealer probably would (expect to be quoted at least 250$us). Some sets I have installed were a 500$ alternator and separate regulator package and the owner has always been delighted. Be aware that 90amp machine will eat near 2hp. That may be critical and if you currently often run at full rack (wide open), you may wish to include a field shut off to get those 2 horses back pulling. It will also destroy drive belts that were less than terrific. Always have at least one spare on hand. I do several of these upgrades in a typical year. If you have any other questions, I'm here a lot. Fair Wind and Smooth Sea Matt Colie ray lunder wrote: Ahoy, I could only find one technical reference for this which claims it's a 30 amp alternator. Could this be correct? That's immeasurable, that's minuscule- that's nothing. I measured about 13.2v output at idle and I had to rev the engine to over half throttle to get 14.4v out of it. (my batteries were topped up at the time if that makes a difference). It's on a 12hp Yanmar one cylinder diesel and I'd like to charge my house batteries (220AH) and a 12v starting battery. If I'm beginning to understand these things I'm to look for an alternator which will produce 30% of my amp hour capacity. Since I'll probably charge the two systems separately I guess that's around 70 - 80 amps. My crank pulley is about 4" diameter, O.D. to O.D.. I need a 3" foot model to fit my engine. Any similar experiences, recommendations, empowering observations? Ok, the spell chek is complete, I had eleven errors. Thanks again. |
#2
posted to rec.boats.building
|
|||
|
|||
Replacement for Hitachi LR135-31 alternator?
Watts to HP....In 1492 Columbus divided the year in two and converted watts
to horsepower. 1492/2=746watts/hp "Matt Colie" wrote in message ... Ray, You got a couple of good answers so far, but I can not resist muddying the water just a little more. The rating published is often optomistic as referenced to sailboat applications as they seldom run at rated speed and are often charging at the top of the recharge curve so they won't be near the published capability. There is an available 90amp unit that is a bolt-in kit. It will just take some looking as I do not have the part number available. I know of two of these installations that were done by owners. A Yanmar dealer probably would (expect to be quoted at least 250$us). Some sets I have installed were a 500$ alternator and separate regulator package and the owner has always been delighted. Be aware that 90amp machine will eat near 2hp. That may be critical and if you currently often run at full rack (wide open), you may wish to include a field shut off to get those 2 horses back pulling. It will also destroy drive belts that were less than terrific. Always have at least one spare on hand. I do several of these upgrades in a typical year. If you have any other questions, I'm here a lot. Fair Wind and Smooth Sea Matt Colie ray lunder wrote: Ahoy, I could only find one technical reference for this which claims it's a 30 amp alternator. Could this be correct? That's immeasurable, that's minuscule- that's nothing. I measured about 13.2v output at idle and I had to rev the engine to over half throttle to get 14.4v out of it. (my batteries were topped up at the time if that makes a difference). It's on a 12hp Yanmar one cylinder diesel and I'd like to charge my house batteries (220AH) and a 12v starting battery. If I'm beginning to understand these things I'm to look for an alternator which will produce 30% of my amp hour capacity. Since I'll probably charge the two systems separately I guess that's around 70 - 80 amps. My crank pulley is about 4" diameter, O.D. to O.D.. I need a 3" foot model to fit my engine. Any similar experiences, recommendations, empowering observations? Ok, the spell chek is complete, I had eleven errors. Thanks again. |
#3
posted to rec.boats.building
|
|||
|
|||
Replacement for Hitachi LR135-31 alternator?
"Dave W" wrote in message ... Watts to HP....In 1492 Columbus divided the year in two and converted watts to horsepower. 1492/2=746watts/hp Several smart answers on conversion of units, but none on efficiency of alternator and that is needed to determine actual HP needed to drive the alternator. The figure Balmar quote is 1HP per 25A output at 14V. Others quote even higher loses. For original poster, this link should provide much of what you need: http://www.balmar.net/PDF/Alternator...or%20Guide.pdf For a 3/8" belt drive, they don't recommend more than 75A. I would not exceed this unless you want a lot of belt problems and the need for a complex system to switch out alternator when you need engine power. Personally, I would stay with the 55A unit. GBM |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Boat Alternator Woes | General | |||
Replacement for Hitachi LR135-31 alternator? | Boat Building | |||
Replacement for Hitachi LR135-31 alternator? | Boat Building | |||
Replacement for Hitachi LR135-31 alternator? | Boat Building | |||
More update on hot alternator. | Cruising |