Alternator, Marine or Auto ?

Richard R

Seaman Apprentice
Joined
Aug 27, 2001
Messages
37
Hello,<br /><br />Boat Info:<br />Freshwater only, pleasure boat, 17' <br />4.3 GM / OMC I/O<br />Problem: Broken Alternator Case / Mount.. don't know how it broke.. odd.<br /><br />Curious as to the general consensus regarding the use of an auto or marine alternator in a boat, locally about $80.00 difference?<br />Doing it correctly is more important than cash... but don't need to waste the cash either :) <br /><br />I did search the forums, several posts regarding complete engine changes and found one post mentioning some alternators using metals that less likely to corrode because of dis-similar metals and thus more compatible with marine use otherwise it said internally they are about the same (except the price).<br /><br />I checked locally (at a marine parts distributor) and they say differently, they say "DEFINITELY.. ANYTHING WITH SPARK OR FUEL must be marine". <br /><br />So I thought I'd check with the vast experience of this board. <br /><br />Regards,<br />Doc
 
D

DJ

Guest
Re: Alternator, Marine or Auto ?

DocWater,<br /><br />You DO NOT want to use an automotive alternator on a marine engine.<br /><br />Marine alternators and starters are shielded to not allow sparks to exit the case.<br /><br />Sparks in a bilge are NOT welcome.
 

scallywag

Seaman Apprentice
Joined
May 4, 2002
Messages
30
Re: Alternator, Marine or Auto ?

I TEND TO AGREE WITH YOUR LOCAL MARINE STORE,IN AN ENLOSED SPACE LIKE YOUR ENGINE COMPARTMENT ANY PART THAT COULD SPARK, STARTER-ALTERNATER MUST BE MARINE.IF THERE WAS NO DANGER YOUR BOAT WOULD NOT BE FITTED WITH BLOWER.
 

Richard R

Seaman Apprentice
Joined
Aug 27, 2001
Messages
37
Re: Alternator, Marine or Auto ?

Yep makes sense to me... <br />Marine is the way to go!!!<br /><br />People and boat replacement would be to hard to do, and it would probably cost more too.<br /><br />Just wanted to be sure I was not getting hosed..<br /><br />You guys are fantastic... Can't wait until I know something I can help someone with... still a rookie :rolleyes: <br /><br />THANKS AGAIN!!
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: Alternator, Marine or Auto ?

Back when I was young,dumb and crazy, I had a mercruiser inboard with a car alternator on it. I had no problems, but it's a miricle I'm here. It just never occured to me that the brushes could come into contact with gas fumes. But that's all it would've taken! I was very religious about venting the compartment before cranking (5minutes minimum), but still,had I known what a dangerous situation it was, I would've spent the extra green for the marine version...It looks cooler anyway :D <br />I never DID make the obvious connection,until I learned it here.
 
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DJ

Guest
Re: Alternator, Marine or Auto ?

All,<br /><br />Just for info.<br /><br />I do not know if any of you out there know how they test the marine components for seal integrity, but here is how it is done.<br /><br />1. Screw a spark plug into the casing of the piece to be tested, whether it be an alt., starter, or distributor.<br /><br />2. Attach the spark plug to a source of ignition-similar to a magneto.<br /><br />3. Fill a test chamber with propane.<br /><br />4. Insert the item to be tested in the chamber and seal the chamber.<br /><br />5. Fire the spark plug repeatedly over a set period of time. <br /><br />6. No BOOM-pass :D , BOOM-no pass :(
 

Richard R

Seaman Apprentice
Joined
Aug 27, 2001
Messages
37
Re: Alternator, Marine or Auto ?

Amendment:<br />djohns19 Testing Procedure.<br /><br />3-A) Bechure da testy chamber maked outa good thick stuff, plastics or glass things are nought good. (you wana here da boom.. not see or feel it)<br /><br />Thx djohns, can't say I'll try it any time soon :eek: !!
 

Walter

Senior Chief Petty Officer
Joined
Jul 3, 2001
Messages
787
Re: Alternator, Marine or Auto ?

Ya might wanna get a hold of Mr. Jasperson to see if he has any deals on marine alternators.<br /><br />Just a thought...<br /><br />Walt<br /><br />PS<br /><br />Get her going soon...the weather's supposed to be very nice over the next few days.
 

Walter

Senior Chief Petty Officer
Joined
Jul 3, 2001
Messages
787
Re: Alternator, Marine or Auto ?

Oh by the way... Who did you get a price quote from? Did you try Napa, Baxters, etc?
 

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: Alternator, Marine or Auto ?

Just for your information only.. If you know how to take apart a alternator. You can get a automotive one and convert it for 16.00 using this kit.<br />
imscrkit.jpg
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: Alternator, Marine or Auto ?

New 94 amp single wire delco www.amarket.com 150.00. May find case/housing at junk yard, switch every thing inside.
 

Richard R

Seaman Apprentice
Joined
Aug 27, 2001
Messages
37
Re: Alternator, Marine or Auto ?

Hi Lo....<br /><br />Hey Walt.... <br /><br />oh yeah.. been shopping, best price was at Napa... although the first quote was about the same as Harvey's, the finial price was about $30.00 less. Lampheres doesn't carry OMC stuff and they even suggested Harvey's or Napa.<br /><br />Have not bothered Garth... figured I would do this one and save the big stuff for him :) <br /><br />All:<br />I really appreciate all the response on this topic, the rebuild ideas are some thoughts I had not considered. I haven't done an alternator before but I had never rebuilt a motor, greased outdrive U-Joints, gotten married, had kids (jury is still out on the last one) and several other things before the first time either. Probably wouldn't be to tough except for the time.. my time is worth money plus, like Walt mentioned.. the weather is FINALLY getting decent around here, from my experience here in Oregon when it does get nice you better get it while you can... <br /><br />I want it fixed NOW, d@## the wallet, full replacement ahead ;) <br /><br />Again, thanks for the input, this board is awesome, thanks to all!!
 
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