Converting an automotive alternator to marine Spec is it possible and cost effective?

[Cptobvious]

Wanting to put a 160 amp alternator on my 85 Penta/GM 350 but cant find a high power alternator that isnt 400+ bucks......is there a conversion kit available or a general do it yourself guide possibly?

 

[achris]

Marinizing an item on an engine involves setting it up to suppress any likelihood of any internal sparks triggering an explosion. Within the alternator there are brushes running on the slip-rings of the rotor. These generate very small sparks as the rotor spins. Nothing can change that, so if there are petrol vapours around there tends to ignite. A marine alternator has mess screens on the open ends to prevent that flame getting out and triggering a wide, more devastating explosion... One of the side effects of the screens is they reduce cooling through the alternator, which is probably why you can't find a cheap one with a high output.

As for a DIY kit... Never heard of one. Possibly because as a DIY it can't be SAE certified.

Just out of curiosity, why do you need 160A? Most of the 'big' alternators for marine are in the 65A area... That seems to meet the needs of most boats....

Chris.......

 

[Cptobvious]

Marinizing an item on an engine involves setting it up to suppress any likelihood of any internal sparks triggering an explosion. Within the alternator there are brushes running on the slip-rings of the rotor. These generate very small sparks as the rotor spins. Nothing can change that, so if there are petrol vapours around there tends to ignite. A marine alternator has mess screens on the open ends to prevent that flame getting out and triggering a wide, more devastating explosion... One of the side effects of the screens is they reduce cooling through the alternator, which is probably why you can't find a cheap one with a high output.

As for a DIY kit... Never heard of one. Possibly because as a DIY it can't be SAE certified.

Just out of curiosity, why do you need 160A? Most of the 'big' alternators for marine are in the 65A area... That seems to meet the needs of most boats....

Chris.......

Thanks for the response............I'm going to be installing a AC system in the boat and wanted to be able to run it off main engine power through an inverter....but if its that big of a hassle and expense I'll just stick with a generator.

 

[NYBo]

Thanks for the response............I'm going to be installing a AC system in the boat and wanted to be able to run it off main engine power through an inverter....but if its that big of a hassle and expense I'll just stick with a generator.

Stick with the generator. Have you priced an inverter large enough to run the AC?

 

[Cptobvious]

Was gonna do a 1500w running 3000w surge modified sine which should be plenty for a 5000 btu AC (500w running) unit and mini fridge (85 watt running).....modified sign isnt as efficient as pure sine so its a little over sized to handle start surge.....ive already tested the setup on a bench and it works good......tried a 1000w unit but turning the fridge and ac on at the same time caused the inverter to go into overload because of the surge......It was an older cheapy chinese unit so that may have been a factor so I just invested in a slightly bigger unit.

The plan was to run the fridge and ac off the motor while cruising and off the generator while parked

 

[farmer9009]

Here is a link for high output marine alternators at lower prices.
http://www.dbelectrical.com/c-10481-high-output.aspx