T-Pain Is On A Boat: Re: [Electric Boats] Well, I am pleased to meet you, won't you guess my name.

Sunday, October 16, 2011

Re: [Electric Boats] Well, I am pleased to meet you, won't you guess my name.

Am I getting every ounce of potential out of the alternators? not nearly.

Am I getting useable voltage for for gas by the pint out of a package that weighs 80 lbs.?

Absolutely.

I'm sure a 1000 lb motor would get more power out of the alternators, but the object of the exercise is pushing the boat.

You're talking about an extra 920lb of motor, plus fuel tanks(s) deck space and the extra hull to keep it all displaced.

With all due respect to your apparent education and expertise, you need to factor in the concept of diminishing returns.

Put down the calculator, walk over to the work bench. All the answers aren't in that little plastic box.

From: Femm <femmpaws@yahoo.com>
To: electricboats@yahoogroups.com
Sent: Sunday, October 16, 2011 8:51 PM
Subject: Re: [Electric Boats] Well, I am pleased to meet you, won't you guess my name.

Okay those would be the Gm-Delco Delcotron and they run from 43 amp to 68 amp output ratings at 14 volts, some were as high as 75 amps for single drive belt. Yes you maybe spinning four of them over. BUT you will not be able to pull full ratings out of all of them at the same time. If I was to put an amp-meter on each output lead it's very likely you are only putting out less then 25 amp per unit.

Lets do the math. 4 Hp X 500 watts= 2000 watts 2000 watts of power is all that you can get out of that gas motor. That also doesn't account for the power losses of your drive belt. I don't care if you are spinning one or ten alternators the total power you can pull is 2000 watts. That works out to 143 amps at 14 volts.

Yeah I can say I'm running a 10,000 watt genset with your 4 HP motor and in fact I can but you slap that system with a 4,000 watt load you A. slip the belt or B. kill the motor. Being able to spin over the alternators is one thing pulling their rated power out of then in something else. My big worm drive skillsaw will kill my friends 2000 watt genset if I try to cut to fast with it and the saw is rated at 1750 watts...

--- On Sun, 10/16/11, Lochadio Who <lochadio@yahoo.com> wrote:

Architects live in a fantasy world.
Engineers live in a perfect world.
and it's up to the field guys to drag them (kicking and screaming) into the real world.

I'm not sure where the gentleman got his information, but...
A 4 horse Briggs and Stratton side shaft with an oil bath air cleaner, (salvaged from my grandfather's 1950's lawnmower)
with an 8" reeve salvaged from an electric dryer will, in fact drive, two 70's era GMC truck alternators (with stock pullies) so well I pulled it apart to add 2 more alternators (and fix the oil leak on the main shaft).

I apologize for correcting our esteemed member, but anyone with any doubts should try spinning an auto alternator by hand.
I'll post a video ASAP

...Before you ask, no, I don't know how many watts it puts out.

Regards

Mark