Alternator off rear end....???

I know an alternator can be used to create resistance. I know thats how the resistance is created in fitness equipment, such as bikes elliptical trainers and most self powered machines.

Maybe an electric assisted brake?

 

The alternator will output well before 2000 rpm, in order to output 60 amps yes I would have to spin the engine around 5000 rpm. However I need no where near 60 amps to power my vehicle, if you read the whole post my car has very limited draw on the system. It's going my my '29 Ford Tudor.....351 Cleveland, T-5, 9inch.

 

i did it once on a model A roadster and it worked fine , put a bigger drive pulley on it and your's will too

 

Here's an interesting set up that was at the Good Guys show in Nashville.

 

^cool

 

I pretty much copied this thread http://www.jalopyjournal.com/forum/showthread.php?t=257368
It works great. It starts charging at 2300 RPM in 1st gear. Once it is charging it stays charging down to about 2 mph. I used a 3 wire alternator.
I would put a larger pulley on yours and never look back. It will work well. Mines been on there a couple months and I drive it quite a bit. Heck, my battery was used when I got it almost 4 years ago and I have not even had a slow crank situation.
Crusty

 

No, typically an alternator is driven at three to four times crankshaft speed. An alternator starts charging at perhaps 500 engine rpm (2,000 alternator rpm) and may reach full output at around 1,500 engine rpm (6,000 alternator rpm) This guy is running the alternator at tailshaft speed with a 1:1 drive.

 

Every time you stop the alternator will have to be re-energized or you will have to get to a pretty high speed to self energize.

A lot of folks run th 3 wire GM and it will energize off the starter solenoid when starting. The engine turns from then until you turn it of. No need to constantly re energize.

I'm thinking in start stop traffic where you dont get over at leat 20 mph each time you take off you will never energize the alt and it will not charge. If you had a way to energize each time the driveshaft started turning it may work better. My .02

 

KY Boy, is this theory? Read my post above. It is real world experience and it works. I am going way less than 20MPH when it starts charging. Hell, I'm still in 1st gear.

 

How are you energizing? 1 wire or 3 wire? You could wire a hot wire in to keep it energized all the time when the key is on but that means you run the possibility of using more power to excite the alternator than you are generating, at least at low RPMS... and you are eating power at a stop. Lets get your finer details out in the air so this post is plenty helpful to folks wanting to do this later.

I'm not cutting on the setup, I'm trying to help the guy get it working the first time. I actually think its a great idea and would use it myself. I just have seen soooo many people have trouble getting the 3 wire setup to energize automatically and end up revving the snot out of the engine to get it started. Many many threads on here about how to wire these things...most people still post multiple times getting them to work...and thats on the engine where its easy to rev charge.

Oh and dang thats one BIG drive pulley inthe thread you referenced compared to the one in this post. May be a big part of your success if yours is that big

 

I didn't realize you were talking about the RPM of the alternator, I thought you were talking engine RPM

 

How about a piece of stainless mesh to keep the debris out of it while still allowing airflow.

 

I am using a Ford alternator with an external regulator.

 

Oh now that I look close at the pic I see that. Without going into a long paragraph and checking the wiring for the regulator I cant really say how that will be different. Does the external regulator have a constant hot+ going to it? If so it can use that to energize. I'm just not that up to speed on the old ford alts.

 

OK I see this set up is on a 9" ford but has any of you tried it on a chevy rearend. I have a 10 bolt in my car and I would love too use something like is set up on my car.

 

KY Boy, the pulley is standard small block chevy crank pulley so it is the same drive ratio as would be hanging on the front of an engine. It isn't going to work on the street with the small pulley the original poster has.
I'm running a 3 wire with the standard exciter wire that comes pre wired in all wiring kits, a heavy gauge battery wire, and the little jumper wire from the battery post to the 2 blade plug in on the alt.

 

Won't work. You need to overdrive the alternator. A lot. Mucho bigger pulley on pinion, smaller on alt.

 

So it seems my design sucks and won't work. I would like to go to a larger drive pulley, I bought that pulley because it was built right into the yoke and I knew it would be round and true. I initially thought about making my own yoke/pulley, but I was afraid that I would not be able to build it just right so it wouldn't throw any belts.

I do have other normal 9inch yokes and pulleys that I could try and build one myself.... however I only have a mig welder and isn't the yoke cast iron and the pulley mild steel? Will I be able to weld the two together with no problems?

Another problem I have is the two other 9inch yokes I have are not like the one picutured here...
http://www.jalopyjournal.com/forum/showthread.php?t=257368

they have a flange/sheild that is close to the seal, I am guessing it's to keep dirt and shit out. In order to put a pulley on one of them I'd have to either cut it in half or cut the flange thing off the pulley.....

let me know what you think

ModelAMafia

 

I think you will find that your yoke is forged steal, and weldable. Based on that assumption, take it to a machine shop and ask them to turn off the pulley flange that is nearest to the rear end an leave the other flange as a straight disc. Give them a flat single grove crank pulley from an early SBC and have them open the center hole to match the diameter that was left by turning off the flange. Now the pulley will slip past the seal area of the yoke and up to the remaining straight flange where you have it tig welded together. I wish I could post a sketch of this but I don't know how. But this will fix the ratio problem and you will be good to go.

Craig

 

put a harley stator under the water pump pully, hidden makes enough to run everything , takes some mchine , fab time. wooks good.

 

Damn thats a great piece of info. I've seen the waterpump alternators but figured the parts were made specific for the pumps. Any particular Harley's, ie Evos or earlier???

 

I did mine in a slightly different way as i've seen diff mounted and the alternator doesn't seem to handle the transmitted shocks very well.
The reason i went this route is that my 394 Olds has 6 x 2 94's and using an alternator didn't look right and caused a visual imbalance of the engine.

The ladder bars were made slightly longer than usual to keep the fulcrum point inline with the yoke UJ, The movement is now only 1/8" on full suspension movement which will be absorbed by the belt.

I've used a 100amp alternator from a Toyota luxury car for its high output, Battery is a large 700amp unit, A 2nd battery is also fitted which is bought into play by a starter button which activates a starter solenoid just in case its needed.





A flange was turned up and welded to the yoke then chucked up in the lathe and trued and drilled for the attaching bolts.






Next a pulley was turned up from aluminium to fit over the welded flange. Diameter is the same as a normal crank pulley.







Here it is bolted together.








Painted and ready for final assembly.





Battery box

 

There is a thread on this where "Chopperman" tried this on one of his builds. I didnt see where he posted back on how it worked out.

I think having it up in the frame near the trans. output shaft would be a better location due to less shock, that the alt. would get being mounted off the diff.
a very slick idea none the less.

 

Here is a photo I took of the setup on Doc's 33 Ford.

 

langy I really like your design, however I don't have to tools (lathe, tig welder) to build mine that way..... hopefully someday.

 

I'm not saying there is anything wrong with this setup but I just don't understand. Why go to all this work just to remove the alternater from the engine bay?

How do you change it on the road if the alternator goes bad. Is there an access panel in the floor pan above it to allow for access? I'm sure that having all the dirt, water and other crap thrown up against it being inches from the road will decrease the alternator's life expectancy. And once that belt gets good and wet I'm sure it will start slipping.

I mean no disrespect...I guess if the setup is used on a vehicle that isn't going to see much road duty it may not be too bad. I just don't see the mechanical benefits...and I barely even see the visual benefits.

The fabrication looks excellent but I'm not sold on the idea.

 

I've used this system before without any problems, As for visual no one wants to see an alternator on a pretty vintage engine do they.

 

Mafia,

I just measured my pulley for you. The drive pulley is 7 inches. My alternator is a small import unit, I think it's from a Mitsubishi. This does overdrive the alternator. Hope this helps.

Doc.

 

If you weld to the yoke and you snap it off due to the tork I want to see photos of the mess it leaves behind.My 2 cents

 

probably not a good mess, but anytime you snap something like that its never pretty.