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  #11  
Old 08-04-2021, 01:37 PM
Wakerider16 Wakerider16 is offline
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Quote:
Originally Posted by ValveCoverGasket View Post
quick google search found these guys
https://lhboulanger.com/

have a lot of positive reviews on google, and they even have boats on their website!


I did look at the name but didn't apparently look hard enough as I figured mechanics vs rebuilds... will be giving them a call in the next hour!
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  #12  
Old 08-05-2021, 05:29 AM
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JimN JimN is offline
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Originally Posted by Wakerider16 View Post
I am in MA (south of boston, Closest major town is New Bedford). I tried yesterday to find someone who could rebuild it for me and had very little luck. Not sure what you were looking at in regards to where I have someone nearby me that could do it but I am all for finding out.
Maybe there's someone you could use in this list-

https://www.yellowpages.com/new-bedf...tor-rebuilders
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  #13  
Old 08-05-2021, 07:55 PM
dpb185 dpb185 is offline
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It sounds like the consensus on this is to uprate your existing alternator. A few questions:

1) Can you go from a stock 51 amp alternator to something around 100 amps or is 70 amps the limit ?
2) Is 70 amps enough to run a modern stereo of say 600 watts output without any issues ?
3) What is involved in going from 51 amps to 70 or 100 amps ? Do they rewind the alternator with more wire or something ?
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  #14  
Old 08-06-2021, 09:30 AM
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JimN JimN is offline
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Originally Posted by dpb185 View Post
It sounds like the consensus on this is to uprate your existing alternator. A few questions:

1) Can you go from a stock 51 amp alternator to something around 100 amps or is 70 amps the limit ?
2) Is 70 amps enough to run a modern stereo of say 600 watts output without any issues ?
3) What is involved in going from 51 amps to 70 or 100 amps ? Do they rewind the alternator with more wire or something ?
I commented on the output for this style case, but that refers to the one on the 2001 (and most other Indmar engines), so it doesn't necessarily apply to the Ilmore version.

P=IE. Power (Watts) = I(Current)xE(Voltage), so use some nominal percentage for amplifier efficiency like 50% (nothing is 100% efficient and I would build in some extra for marketing BS when they show 80%) and use 12 as the voltage, or you WILL have problems because most people use their stereo a fair amount of the time when the engine is idling or off and the alternator doesn't output 14V below about 2000 RPM.

600W/12V=50A at 100% efficiency, so a 51A alternator is useless at the start because the engine and all of its electronics need at least half of that before you turn on any of the boat's accessories. That leaves you to require at least 100 if you really pound the stereo and you always need to design for worst case scenarios.

Usually, the stator and armature are the same, but the regulator is beefier, although you could call and ask what YOUR local shops do. Also, ask about an external regulator.

If you do use a heavier duty alternator, make sure to increase the gauge of the battery cables- the OEM cables are sized for the OEM alternator, not something that can deliver twice the current.
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  #15  
Old 08-06-2021, 11:02 AM
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ValveCoverGasket ValveCoverGasket is offline
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on that note regarding upgrades/output - all the alternators ive had done by our local shop have also come with little alternator dyno plots where they show actual output v shaft rpm (youd have to do the math on how that translates to engine speed but thats easy if you measure the pulley sizes).

usually they end up being 20-25% above their rated output after their work.
what they do to them to achieve that, and if its normal, im not sure.
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  #16  
Old 08-06-2021, 12:07 PM
dpb185 dpb185 is offline
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I'm just trying to get all the info on this I can before I really need a new alternator (ie current one stops working) and have to do it on the quick. Mainly is there some sort of physical limitation to uprating my current 51 amp alternator to 100 amps and if so, will 70 amps be sufficient for future stereo upgrades ? Or is there and off the shelf alternative ? I've seen a lot of posts by people saying they had to grind down parts of off the shelf alternators to make then fit and that makes me nervous. 5.7L Indmar LTR engine by the way.
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  #17  
Old 08-06-2021, 04:20 PM
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JimN JimN is offline
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Quote:
Originally Posted by dpb185 View Post
I'm just trying to get all the info on this I can before I really need a new alternator (ie current one stops working) and have to do it on the quick. Mainly is there some sort of physical limitation to uprating my current 51 amp alternator to 100 amps and if so, will 70 amps be sufficient for future stereo upgrades ? Or is there and off the shelf alternative ? I've seen a lot of posts by people saying they had to grind down parts of off the shelf alternators to make then fit and that makes me nervous. 5.7L Indmar LTR engine by the way.
There are limitations, but the shop will need to let you know about them. Since there'sno such thing as 'free power', the stator and armature will have limits, but the regulator does, too. A higher output regulator won't fit in/on the housing.

If you want to future-proof the alternator, don't 'get by' with 70A- that's not enough and your existing alternator is probably rated for that- look on it for some indication of capacity.

The reason I recommend rebuilding and upgrading to the highest capacity is so you DON'T have to grind anything and it's a direct fit.
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  #18  
Old 08-06-2021, 06:58 PM
dpb185 dpb185 is offline
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Quote:
Originally Posted by JimN View Post
If you want to future-proof the alternator, don't 'get by' with 70A- that's not enough and your existing alternator is probably rated for that- look on it for some indication of capacity.

The reason I recommend rebuilding and upgrading to the highest capacity is so you DON'T have to grind anything and it's a direct fit.
My thought exactly, plan for replacement and get what I want or settle for what I can get when it becomes an emergency.

I'm pretty sure I have the original alternator, need to double check. Except for the radio head unit, I haven't found anything else in the boat has been replaced or upgraded.

Which isn't a bad thing, there isn't much wear and tear, it still has the original 2000 interior for example.
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  #19  
Old 08-06-2021, 07:08 PM
Tsumi Tsumi is offline
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When I went around looking to rebuild our LTR alternator, it was significantly more expensive than buying a brand new one (was quoted $180). The one I linked is $85 and puts out 70 amps. I only needed to grind about 1/4" of material off of the alternator bracket.

https://www.ebay.com/itm/27390829453...sAAOSwCTBbO6lm <-- I think we put this one in the X-Star. 95 amps. Can't find the receipt so I can't verify.
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  #20  
Old 08-06-2021, 07:58 PM
dpb185 dpb185 is offline
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Quote:
Originally Posted by Tsumi View Post
When I went around looking to rebuild our LTR alternator, it was significantly more expensive than buying a brand new one (was quoted $180). The one I linked is $85 and puts out 70 amps. I only needed to grind about 1/4" of material off of the alternator bracket.

https://www.ebay.com/itm/27390829453...sAAOSwCTBbO6lm <-- I think we put this one in the X-Star. 95 amps. Can't find the receipt so I can't verify.
Did you swap your existing pulley to the new alternator ?
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