Alternator 220amp on 1gm engine? need advice

Bill Roosa · Mar 23, 2014

You would need either double belts or a serpentine belt to drive it.
Yes it will put several HP load on the engine.
This is all kinda moot as your 27' boat probably does not even have a battery bank that can accept that amount of current. You would need something like 880 AH of storage to even make this practical.
Before you go buying parts you need to understand how batteries charge and the parameters around balancing electrical use, production and storage.
How do you use the boat? day sailor, weekends
What electrical equipment do you have on board?
how big is your house battery bank?

Once you know how much electricity you need you can size the batteries so you can recharge in a fashion that supports how you use the boat.
With all that said, a bigger house bank is always a good idea if you have the room.

Benny17441 · Mar 23, 2014

The older 1GMs had 6HP. A 55A alternator would be about the higher limit I would consider using and even then it would seriously curtail engine performance to drive the boat.

seadaddler · Mar 23, 2014

?????

Why do you want 220 am alternator and I think anything bigger than your
55 am alternator will rob too much from your 6HP engine.
Nick

Alan Gomes · Mar 23, 2014

Benny17441 said:
The older 1GMs had 6HP. A 55A alternator would be about the higher limit I would consider using and even then it would seriously curtail engine performance to drive the boat.

That alternator is way too big.

I have a 6.5 hp 1GM in my Ericson 26-2. Mine has the factory alternator, which for that engine is 35 amps. I would say that is about right. When my house bank is low, I can definitely tell a difference when the alternator is working hard. I'd say there is absolutely no way you could drive a 220A alternator with a 1GM. Besides, for your 27 footer the engine is already significantly underpowered, so you don't want to reduce the power any further.

Bill Roosa · Mar 23, 2014

Hey Wesley
went to the link and a couple of observations
the 220 amp alternator is shown with a single pulley. that ain't happenin, no way no how. About the max HP you can get in a single belt is 1.5 or 75ish amps of current.
It list your motor and other small motors and I believe that those motor could power this beast. A 1 HP motor could power a 51ish amp alternator so a 6 HP motor could in theory power this beast but I'm thinking that this is a genset sort of solution not a inboard that also powers an alternator.

Maine Sail · Mar 23, 2014

Bill Roosa said:
Hey Wesley
went to the link and a couple of observations
the 220 amp alternator is shown with a single pulley. that ain't happenin, no way no how. About the max HP you can get in a single belt is 1.5 or 75ish amps of current.
It list your motor and other small motors and I believe that those motor could power this beast. A 1 HP motor could power a 51ish amp alternator so a 6 HP motor could in theory power this beast but I'm thinking that this is a genset sort of solution not a inboard that also powers an alternator.

Also the alt shown is a Cheap Chinese Hitachi knock off yet it is described as a Delco CS130.. Caveat Emptor on anything from that vendor..

Alternator 220amp on 1gm engine? need advice

wesleysherman

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Bill Roosa

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Benny17441

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seadaddler

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Alan Gomes

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Bill Roosa

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Maine Sail

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