Alternator
Nits78
Quick question. Is it absolutley necessary to use a marine grade alternator on
a mercruiser 454 ? What are the differences if any ? If so, how much do you
guys think they are going to bang me for a job like this ?
Thanks,
Nits78
Gould 0738
I'd be less worried about the "banging"
and more concerned with the potential
"ka-boom!"
Use of an automotive alternator on a gasoline engine like a 454 is dangerous.
Auto alternators are not shielded to prevent sparking. One little spark in a
bilge with gasoline vapors and you could enjoy a bird's eye view of what's left
of your boat,
You boat with a 454, (how many gallons an hour?) and you want to save a hundred
bucks with a dangerously sub standard
part?
Step up and get the good stuff.
Or, better yet, look into having your old alternator rebuilt. That's just about
a $hun, locally.
Good luck.
________
Chuck Gould
Float and let float.
Rob
contain anything that would produce a spark -- i.e. no brushes. Except for
extra paint, I could never tell the difference between them?
Rob
Gould 0738 wrote in message
<19990830104408...@ng-cs1.aol.com>...
Nits78
However, I never stated that I wanted to save money on a substandard part and
risk burning down my boat. I was simply asking how much a marine alternator
costs vs. an automotive alternator and whether there was a difference in
construction because I don't know. I kind of got the answer, but there was no
need for you to ASSume I'm a cheapskate and not willing to "step up and get the
good stuff."
Damn, Can't anybody ask a simple question without getting flamed around here.
>I'd be less worried about the "banging"
>and more concerned with the potential
>"ka-boom!"
>
>Use of an automotive alternator on a gasoline engine like a 454 is dangerous.
>Auto alternators are not shielded to prevent sparking. One little spark in a
>bilge with gasoline vapors and you could enjoy a bird's eye view of what's
>left
>of your boat,
>
Just Some Guy
"one size fits all" so some adaptations may be required. If you have an odd pulley
size (like volvo) it gets tricky. Rebuild cost in my area is $100 - $250. It is
true that marine alternators and starters must have sealed brushes so there are no
hot sparks in the bilge.
People do make assumptions, if it is someone who is a cronic "pain in the butt" it
is annoying but I don't think this is the case with Chuck. If someone is
knowledgable and has help out on the NG by giving good answers and ideas then let's
give him a break. I try to never assume anything. Keep in mind the person you
flame could be the next president (or the next mass murderer)!!!
--
Regards,
John G.
--
NJ Coastal and ICW - Somers Point / Ocean City
Marcus G Bell
> Is there really a difference between the two? Automotive
> alternators do not contain anything that would produce a spark
> -- i.e. no brushes. Except for extra paint, I could never tell
> the difference between them?
Automotive alternators DO have brushes to carry current to the
rotor. That's the "field" current. They CAN spark.
I'd imagine the marine unit has wire mesh in important places to
arrest the spread of flames.
-- -- Marcus. ( be...@mail.med.upenn.edu )
George Jefferson
nobody seems to know specifically what the difference is, so they need
to resort to colorful scare tactics.
It is my suspicion that marine electronics are often identical
parts, but passed through a higher level of inspection / QC.
(right there is your cost and justification).
--
george jefferson : geo...@sol1.lrsm.upenn.edu
to reply simply press "r"
-- I hate editing addresses more than I hate the spam!
RBStern
>Damn, Can't anybody ask a simple question without getting flamed around here.
Nits, perhaps Chuck jumped to a wrong conclusion, but he wasn't flaming you.
Not his style.
Also, it's "be-nice-to-Chuck-week" because someone used his boat for battering
ram practice.
Rich Stern
Ron White
with) do contain brushes. These brushes ride over smooth copper rings on the
armature and are not the source of much arcing but as anything electrical
they can arc causing sparks. I some cases on automotive engines that are
converted for marine service, the alternators are basically automotive unit
that have been converted to marine service by adding a screen over the rear
end and an outer housing that covers most of the holes in the alternator
housing. The screens and coverings will do prevent explosive vapors from
entering the alternator but they will give some measure of protection
against sparks from being thrown out into the engine bay. Another thing is
the pulley. Generally you would use a larger pulley due to the sustained
higher RPM of the marine engine vs. the car.
As to whether or not you should use the auto unit, I would use the marine.
You can usually get a auto unit converted to marine by a alternator shop
that does marine work. The conversion should not be over 75 or so. When or
if the Coast Guard inspects your boat they are supposed to check for marine
electrical items such as alternators and starters.
There are more fancy marine alernators but we are just talking the basic
minimun here.
--
Ron White
Check out HAMMER the 30' sportfisherman I am building
http://www.concentric.net/~knotreel
Carl G. Craver
The biggest difference is "flash-proofing".
That means that any spark produced by the alternator is internal, and that
all the vents and openings in the alternator are shielded to keep any flames
and explosion inside the alternator.
The same holds true for starters, relays, distributors and most other
electrical devices.
As a rule of thumb, if it has to do with electrical, or fuel, it has to be
MARINE.
Carl G. Craver
Evinru...@home.com
PS: Just see the earlier post on the boat explosion at Martha's Vineyard to
see what happens.
George Jefferson wrote in message <7qefvb$fcb$1...@netnews.upenn.edu>...
>:Damn, Can't anybody ask a simple question without getting flamed around
here.
>
Steven Shelikoff
>
> Hi,
>
> Quick question. Is it absolutley necessary to use a marine grade alternator on
> a mercruiser 454 ? What are the differences if any ? If so, how much do you
> guys think they are going to bang me for a job like this ?
There are a lot of differences between marine grade alternators and auto
alternators. For you, the only difference of any importance is
spark/flame arresting mesh. You're not going to be charging large house
batteries like a sailboat would, so the ability to withstand high
amperage output for a long period of time isn't important to you.
Putting out max rated current for a long period of time would quickly
cook an automotive alternator.
Steve
--
/ / /
\ \ \ mailto:shel...@averstar.com
/ / /
Rob
Carl G. Craver wrote in message ...
>There is a huge difference between an automotive alternator and marine.
>The biggest difference is "flash-proofing".
I can appreciate this concept and it certainly applies for starters, relays,
& distributors where arcs occur. However, with modern day alternators there
are no brushes or anything else that would produced an arc. Beside some
extra paint and/or conformal coating I am wondering if there really is a
difference. If there is some extra "flash-proofing" what is it put around?
They both look the same to me...
Rob
Brian Runyard
> Rob
> However, with modern day alternators there
>are no brushes or anything else that would produced an arc
Rob
If you take a good look at an altenator, you'll see they DO have brushes.
It's the only wat to transfer the power to/from the Rotor.
Brian
Phoenix
Chuck response was not a flame, he was making a comment to whomever reads
your post and his answer that THERE IS A DIFFERENCE. After you read this NG
for awhile, you will see it was a very civil response, just sometimes a
response might seem to be a flame because you miss all of the body language
that goes along with normal conversation.
He was trying to be helpful to you and anyone else who is reading this
thread. Enjoy the NG, but enjoy your boating even more.
--
Jim
1994 Regal 256 for sale - see ad at
http://www.classifieds2000.com/cgi-cls/ad.exe?P1+C189+R1187463
Nits78 <nit...@aol.com> wrote in message
news:19990830115551...@ng-fl1.aol.com...
> Thanks for your reply Chuck,
>
> However, I never stated that I wanted to save money on a substandard part
and
> risk burning down my boat. I was simply asking how much a marine
alternator
> costs vs. an automotive alternator and whether there was a difference in
> construction because I don't know. I kind of got the answer, but there
was no
> need for you to ASSume I'm a cheapskate and not willing to "step up and
get the
> good stuff."
>
> Damn, Can't anybody ask a simple question without getting flamed around
here.
>
Gould 0738
>Thanks for your reply Chuck,
>
>However, I never stated that I wanted to save money on a substandard part and
>risk burning down my boat. I was simply asking how much a marine alternator
>costs vs. an automotive alternator and whether there was a difference in
>construction because I don't know. I kind of got the answer, but there was
>no
>need for you to ASSume I'm a cheapskate and not willing to "step up and get
>the
>good stuff."
>
>Damn, Can't anybody ask a simple question without getting flamed around here.
>
Hey, Nits.........
Somebody using your e-mail address posed a question here, along with a remark
that they thought they'd be taking a "banging" by paying the difference between
a car part and a suitable alternator for a boat. You might want to figure out
who that
was, cause I might not have been the only
dum dum to make the ASSumption that price resistance was a prime motivator
behind your inquiry.
As for flames.........you must be recently arrived on rec.boats' shores. It
takes a blowtorch 'round here to generate a
flame worthy of note. Consider my post just a "harmless" little auto parts
spark, ok?
Again, good luck to you.
C>Thanks for your reply Chuck,
Rob
contain a couple of slip rings. I guess I have developed a mind set from
hanging around to many outboards where it's not done this way.
Rob
Brian Runyard wrote in message <7qg6tv$ve3$1...@trog.dera.gov.uk>...
Bryon Kass
an automotive alternator. Doing this increases the possibility
of causing an explosion if you have any fumes. Marine
alternators for gasoline boats are built to prevent this explosion
potential. I can get you rebuilt marine alternators without core
deposits. Get back to me for more info.news:19990830101619...@ng-fy1.aol.com...
> Hi,
>
> Quick question. Is it absolutley necessary to use a marine grade
alternator on
> a mercruiser 454 ? What are the differences if any ? If so, how much do
you
> guys think they are going to bang me for a job like this ?
>
> Nits78
Jared Sherman
There is one other difference. If he repowers with a non-marine grade
alternator, that equipment will not be USCG or ABYC approved for use on
a boat. (Mainly because of the spark/flame arresting.)
IF anything happened and there was a fire or explosion on the boat, any
insurance he has might be voided because of the use of non-certified
equipment. And if something happened to the "next owner" of the boat,
there would be grounds for a liability lawsuit because of the unsafe
equipment.
Just something to think about when considering the final balance.
--
Jared Sherman
Reply to: jareds...@worldnet.att.net
Steven Shelikoff
That's a legal difference, not a physical difference. But it is a good
one.
brian whatcott
>
>Jared Sherman wrote:
>>
>> Steve-
>> There is one other difference. If he repowers with a non-marine grade
>> alternator, that equipment will not be USCG or ABYC approved for use
on
>That's a legal difference, not a physical difference. But it is a good
>one.
>
>Steve
The physical difference amounts to little more than a copper gauze
over any airway between a spark source and the outside
environment.
Try placing a copper gauze sheet over a gas flame.
You can light below, enxtinguish above, or
light above, and extinguish below.
works like magic!
Brian Whatcott Altus OK
Steven Shelikoff
It's actually more than just that physical difference. Try taking an
auto alternator that's rated at, let's say, 60 amps and actually draw 60
amps from it for any length of time while it's in a hot environment like
an engine compartment. You'll quickly burn it out because it can't get
rid of heat fast enough. Try the same thing with a high quality marine
alternator and it will last much longer.