Smallblock alternator relocation ideas?

-
Johnny Mac

Johnny Mac

www.blueprintengines.com
FABO Vendor
Joined
Jul 10, 2010
Messages
4,340
Reaction score
4,837
Location
OHIO
I've got an issue with throwing my alternator belt. I have an electric water pump, so my belt only runs from my stock crank pulley, to a powermaster (chrysler case) alternator. Also manual steering so literally the only accessory using the belt and pulley.

I believe the issue is the fact that it's a 140 amp..so i can only imagine the draw it's under at my shift point of 7200 RPM. So i'm asking alot of the belt to stay on at that point.

Anyways, i think the best answer is probably to try to low mount the alternator, and get a shorter belt on it so it can't bounce and walk like i'm sure it does now.

anyone else relocate their alternator? any pictures? does someone else have another idea altogether like switch to a gilmer belt and pulleys? I'd rather not ditch my newish, nice, properly functioning alternator.

appreciate the feedback.
 
I've heard some of the guys are using the serpentine setup from the magnum engines...
 
put a larger pulley on the alternator which slows it down....or get a smaller crank pulley which slows the alternator down also...
 
mguner said:
I've heard some of the guys are using the serpentine setup from the magnum engines...
Click to expand...

Something about the physics of the shallow grooves on a serp almost make me think it'd be worst? But I dont know.

A bigger alt pulley makes sense. Wonder how much that would affect the output?
 
Most alternators reach full output at somewhere around 5-6K RPM at the alternator. Some of the newer stuff is lower, and some starts to "really put out" on the curve below that. This info USED to be available. We used to have a Delco catalogue about a foot thick that listed all this.

I remember that I started having trouble in my old 70 RR V code, and figured out that if the engine was spinning 5-6K, the alternator was about 4X that, so 20-24,000 RPM. "They" didn't like that
 
Ken: would love a picture. Thank you.

Straight line...believe me I know. If I can get a bracket fabbed up I will see if someone with a cnc can punch them out.

67: yes im sure at 7300 im not in the optimal range. Now if I can just find a bigger pulley with the correct bore...
 
So I see a 5 inch pulley is gm shaft only, and 30 freaking dollars. So I guess I Will be reaming it out to fit the mopar shaft.
 
I moved mine to the drivers side tweaking the original brackets and a GM alternator
 
we use a 30% moroso underdrive pullley on the crank....never had a problem keeping the batteries charged......we dont have to charge between rounds...and very seldom charge the batteries before we go to the track.
 
70aarcuda said:
we use a 30% moroso underdrive pullley on the crank....never had a problem keeping the batteries charged......we dont have to charge between rounds...and very seldom charge the batteries before we go to the track.
Click to expand...

Moroso 64700? Whats it weigh? That a solid hunk of billet?
 
I have a whole thread somewhere about the same problem and I resolved it by buying and March performance underdrive pulley. no belt throughing anymore at all. The March pulley protruded out far enough to get the belt around the more protruding electric water pump than stock. It is a two groove pulley that I use the outer groove. I'll even throw in a picture here of the mark the belt made when it flew off at the top of second gear with the old pulley. I seen it shoot out of the preferable of my right eye I thought keep your foot in it and got my best time of the day! Lol View attachment 20150623_130615.jpg

View attachment 20150623_195655.jpg

View attachment 20150613_142139.jpg
 
j par said:
I have a whole thread somewhere about the same problem and I resolved it by buying and March performance underdrive pulley. no belt throughing anymore at all. The March pulley protruded out far enough to get the belt around the more protruding electric water pump than stock. It is a two groove pulley that I use the outer groove. I'll even throw in a picture here of the mark the belt made when it flew off at the top of second gear with the old pulley. I seen it shoot out of the preferable of my right eye I thought keep your foot in it and got my best time of the day! Lol View attachment 1714837473

View attachment 1714837474

View attachment 1714837475
Click to expand...

So you pretty much ran spacers on the water pump bolts and left it in the stock location, with an aluminum pulley
 
johnnymac2k6 said:
So you pretty much ran spacers on the water pump bolts and left it in the stock location, with an aluminum pulley
Click to expand...
yes - I had to run a one inch spacer on the alternator as well, and some longer bolts. All relatively easy to find at the local hardware store. I am going to look for that thread as I was asking all of this and I documented what I did as i was not getting any good advice.
 
Thanks Jpar. Im kind of fighting two battles at once with wanting the belt to stop throwing, and mounting an electric pump with an alternator. I figured I can run spacers like that too, but I guess I need to slow the thing down with whichever pulley is the less evil to change.
 
johnnymac2k6 said:
Thanks Jpar. Im kind of fighting two battles at once with wanting the belt to stop throwing, and mounting an electric pump with an alternator. I figured I can run spacers like that too, but I guess I need to slow the thing down with whichever pulley is the less evil to change.
Click to expand...
I've never tried pulling the alternator pulley and the march Proformance is a hundred bucks. It's a spendy piece, but very easy to put on.
I was in the same boat. I just laid out the stock pump and new electric one (with backing plate) flat and measured the difference from front to back (thickness). Lets say that the new electric pump protruded out an extra inch than stock - now the alternator bracket is pushed out another inch. Now the alternator must be spaced another inch to be flush. With my new Proform electric water pump and March performance underdrive pulley (3 inches from harmonic balancer to center of v) the belt cleared the water pump intake hose by 3/4's oof an inch. I did have to modify the triangle bracket to fit the electric pump. I'll go out to the garage and take some new pictures and post in a few minutes.
 
The March performance is bilit. The first picture the two spacers for the alternator that I used, the middle space is the stock one. also I have a picture of the stock triangle bracket modified and a little extra material welded on the underneath side to give it strength because it got the little thin on the underneath side. I've also included a picture of the clearance that I have for the belt to pass the inlet hose and I have a little orange thing there showing the space that's needed no matter which underdrive pulley you choose, if you so choose to go that route. And as 70aarcuda said NO MORE THROUGHING BELTS :thumleft:View attachment 20150818_070801.jpg

View attachment 20150818_071114.jpg

View attachment 20150818_071032.jpg
 
Truly my biggest problem was getting the belt around that inlet for the electric water pump. I was going to try putting it on the other side but I figured it would really get in the way of my timing marks. if you got the Proform water pump I bet you got a great laugh out of the bolts that came with it? I have yet to figure out with that goes to? Lol
 
70aarcuda said:
Description says it is cast aluminum ....but certainly lighter than a stock steel pulley....

and it does not throw the belts...
Click to expand...

I guess the picture is misleading...the unmachined surface in the middle appears to be alot more meat than i think it'd need.


thanks everyone for the pics and references. i will post what i come up with. i ordered this monster looking moroso pulley, some spacer tubes, and my water pump is in fact the proform (after tossing the little moroso drive motor)

hopefully get it all installed this weekend.
 

Attachments

  • 710-64700.jpg
    30 KB · Views: 476
You can't change the alternator pulley instead of the crank?
 
I saved all the small crank pulleys I could from mostly irrigation engines and that took care of most of my belt throwing issues on single belt applications anyway.
 
67Dart273 said:
You can't change the alternator pulley instead of the crank?
Click to expand...

well the only thing i have on the crank is the alt, and i truthfully don't know if the alt pulley is press on or bolt on. haven't been out to look. I also didn't see a larger mopar alt pulley being marketed for chryslers. Just ones that say Gm/Ford...so that would lead to be reaming out the bore to fit the mopar. At the end of the day i found the moroso pulley for $50, and i know that it's only bolted on...so seems easier at the end of the day.
 
You must log in or register to reply here.
-

Back
Top