[C320-list] Alternator

[Warren Updike]

I just completed this project last spring.  I used Jack Rabbit Energy for 
all the equipment and would recommend them.  www.jackrabbitmarine.com  I'm 
happy to tell you about my experience.  I have pictures and details such as 
the wiring diagram for the engine harness, and overall wiring diagram for 
the whole project.  If you contact me directly (e-mail or 410-821-8246) I'll 
bend your ear for a while, and sent you all the documents.

Your question: I went with the AmpTech 125A alternator.  This has a US 
standard dual foot mount.  Unfortunately, the Perkins M-30 alternator mount 
is not standard.  It does not line-up fore and aft with the pulleys.  I had 
to have the mounting bracket modified at a machine shop.  That was simple 
and inexpensive to do.

The case of the alternator (any high-output model) will be substantially 
larger than the 55A Lucas original.  This led to the need to modify or 
replace the adjusting arm that goes over the top.  There must be a simpler 
way to approach this part than what I did; but, my approach does work.  I 
found an extension bracket in an auto store and had it welded onto the 
original bracket, offset to allow for the further aft location of the new 
connection on the alternator.  I then had to grind down the modified bracket 
to allow sufficient movement of the alternator to install/remove the belt 
and have adjustment room to keep the belt sufficiently tight.  There is 
precious little space to twiddle with.  There is a coolant hose above this 
bracket and to get enough vertical movement, I had to grind the bracket at 
an angle to match the shape and route of this hose.  Also, had to lengthen 
the oblong hole down.  This took about a dozen dry fits and grinding 
sessions.  Nevertheless, it is done.

I also installed: a Balmar ARS-5 voltage regulator, separate starting 
battery charged via a Blue Sea CL-ACR combiner, Blue Sea e-series dual 
circuit master switch to replace the 1-both-2-off switch, and an XBM 
monitor.  The monitor is essential.  It's a vast improvement and allows us 
to stay on the hook with a minimum of engine time.  It's well worth doing if 
you are a cruiser and want to maximize time on the hook.

If I had it to do over again, I would consider the Balmar 6-series 
alternator for two reasons: 1) if the case is smaller, you'll have more room 
around it; 2) and, this is a point I completely overlooked, with only a 3/8" 
belt, the max. output recommended for the alternator is about 80A.  (I have 
a chart of the output curve for this alt. on the M-30.)  The ARS-5 allows me 
to program it to reduce the output; but, if another 70 to 100A alternator 
has a smaller case size than the AmpTech, I would have used that.

The rest of the project involves running new wires from/to the alternator, 
installing shunt, fuses, buss bars, etc.  Lots of fun you will have 
regardless of which alternator you choose.

There is lots more to talk about; but, I'm sure Ive reached the text 
tolerance on this list.

Warren & Pattie Updike
C320, #62, 1994, "Warr De Mar"
Frog Mortar Creek, Middle River
Chesapeake Bay

----- Original Message ----- 
From: <brer at adelphia.net>
To: "Catalina" <c320-list at catalina320.org>
Sent: Monday, February 25, 2008 12:02 AM
Subject: [C320-list] Alternator


>I want to change from the stock 55 amp alternator to one that puts out more 
>amps. I went to the Balmar web site, but the info there doesn't tell me if 
>there is a direct bolt on for the M-30 Perkins. Has anyone made this swap? 
>if so what amperage did you select, and a part number would be great. 
>thank you  Don
>
>