Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Overdrive Pulleys

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by kpanza, Jul 1, 2003.

  1. kpanza

    kpanza 1/2 ton status

    Joined:
    Dec 8, 2000
    Posts:
    1,579
    Likes Received:
    0
    Location:
    Lake Forest, Orange County, California
    Hey, does anyone know where I might be able to get some Overdrive pulleys (not the Underdrives!) for my power steering and alternator? Want to get some extra amps at idle and also some extra steering boost at low rpms...

    Thanks for any info...
     
  2. Big Red

    Big Red 1/2 ton status

    Joined:
    Jan 9, 2003
    Posts:
    250
    Likes Received:
    0
    Location:
    Bristol, CT
    easiest and cheapest way, go to a machine shop with a lathe or cnc mill. give them the materials and specs, theymill it out, u give them cash, u go home and install for free. better than paying $100+ for a set of pulleys. /forums/images/graemlins/thumb.gif
     
  3. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    I don't know where to find the one for the power steering, but check with Dorian (dyeager535) on the one for the alternator. He bought one recently. /forums/images/graemlins/cool.gif
     
  4. kpanza

    kpanza 1/2 ton status

    Joined:
    Dec 8, 2000
    Posts:
    1,579
    Likes Received:
    0
    Location:
    Lake Forest, Orange County, California
    Ok, will do...yeah, my buddy Tony (tonypeebs) can machine some for me, was just hoping to get them quick and easy from a shop that sold them...
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    Here's some of my previous posts:

    [ QUOTE ]
    To be honest, stock older alternators are pretty bad for idle output, mines an 87 amp unit that I rebuilt, and works fine, but no difference than before...low idle output voltage. Increasing RPM by about 300 bumps output into the 13V+ range, but increasing idle speed that much is pretty drastic. Also tried approx. 33% overdrive pulley with it (turned it faster), no dice. Thats with stock stereo, HD heater on high, headlights on, and nothing else.


    [/ QUOTE ]

    [ QUOTE ]
    Just don't forget, (for example) if you went from a 3" to 2" pulley, you increase the alternator speed by 33%, and since its already "overdriven" from the motor because the crank pulley is larger, you will have to be careful not to get crazy with overdriving it...you increase wear on the alternator, and apparently at ultra high RPM's, they can or will self destruct.

    [/ QUOTE ]

    [ QUOTE ]
    Got a response back from www.powermastermotorsports.com about the OD alt pulleys.

    Part# 110 for chrome and 111 for
    natural. 2 3/8". No price given.

    If its only $10-12, (the serpentine ones aren't much) I may try it. Thats not MUCH of an OD ratio, but its a bit. Can't hurt to try!


    [/ QUOTE ]

    Can't find where I replied with my results, but they weren't good. Didn't see any increase in idle voltage that was worth measuring. Something like .2 volts. Still dimmed the lights when I turned the heater on at idle.

    I actually turned around and sold it to someone on here, can't find that info either, you could have asked how it worked for them. /forums/images/graemlins/frown.gif
     
  6. BadDog

    BadDog SOL Staff Member Super Moderator Author

    Joined:
    Feb 24, 2001
    Posts:
    7,777
    Likes Received:
    11
    Location:
    Phoenix, AZ
    I've also been looking for an overdrive pulley for my PS pump to help it keep up with Hydro boost, and Hydro Assist. I've about decided I'll need to run 2 pumps to get what I want, but I've still got a few things to try first...

    On the alt, might be worth looking into upgrading to one of the late model 130(?) amps. Much better low rpm output.
     
  7. kpanza

    kpanza 1/2 ton status

    Joined:
    Dec 8, 2000
    Posts:
    1,579
    Likes Received:
    0
    Location:
    Lake Forest, Orange County, California
    BadDog, that's exactly what I'm trying to solve...I've got the WTOR Redneck Ram assist, AGR SuperPump (with the WTOR tech trick mods), AGR steering box, and I still have subpar asist at low-idle rpms...figured I would try the overdrive pulley to spin it faster, since when I increase the engine rpms, the steering gains much more assist...but you can't just go flying over the rocks to try to get the steering to work better!! /forums/images/graemlins/smile.gif

    I've also got a Powermaster 140 amp alt, but still can't keep up with my electrical loads...
     
  8. BadDog

    BadDog SOL Staff Member Super Moderator Author

    Joined:
    Feb 24, 2001
    Posts:
    7,777
    Likes Received:
    11
    Location:
    Phoenix, AZ
    But is it the small body? IIRC, the small body, late model 135(?) amp alternators are specifically designed for much higher output at lower rpms. I checked mine a long time ago, and seems like it puts out just over 12 at 600-700 rpm idle and around 13 at 1000, but it's been a long time and I could (likely) be wrong on what readings I got at what rpms...

    On the ram assist, I've got the worst possible combo. Hydro boost brakes with 2" hydro assist ram. Even with the volume mods, it just can't keep up. /forums/images/graemlins/frown.gif I've got another pump (remote res) that I'm going to play with as I put the latest changes back together. I'm going another 1/64 larger on the valve hole, but I'm afraid that will be too much and I'll loose pressure. It felt like I got a little less "assist" on the last hole size, but it was so close I could be just paranoid. And before someone says to do the pressure mods, the "pressure mods" won't help if the hole is too big. I have not done anything to alter pressure as I think it is unnecessary...
     
  9. DieselDan

    DieselDan 1/2 ton status

    Joined:
    Jan 27, 2001
    Posts:
    1,056
    Likes Received:
    0
    Location:
    Vermont
    I'm the one that bought Dyeager's altenator pulley. 'Had similar results: didn't help much at idle, but it did allow the volts to kick up alittle quicker off-idle. Works good with the diesel on fast-idle (cold) as it can actually start charging before "moving out". I suspect the smaller pulley may be more prone to slippage and squealing /forums/images/graemlins/smirk.gif

    Oh ya, wasn't I reading some post on aftermarket power steering pumps. I think they offered a smaller pulley for the "P" series pumps (is that our Saginaw /forums/images/graemlins/confused.gif ).
    /forums/images/graemlins/usaflag.gif
     
  10. kpanza

    kpanza 1/2 ton status

    Joined:
    Dec 8, 2000
    Posts:
    1,579
    Likes Received:
    0
    Location:
    Lake Forest, Orange County, California
    Yeah, the Powermaster is the same as the old Delco small body units...I have heard that the later model SI series, big case alts are nice, may try to fab up some brackets to get it to mount. My electrical system has always been a sore point on my truck...someday I will rip it all out and get a Painless kit to make sure everything is right...

    The first time I messed with drilling the pressure fitting to a larger size, Matt at WTOR still had the old instructions on his site...basically said to drill out the hole up to a 1/8 bigger than what you started with...well, he has now changed his directions to say that the hole should end up no larger than 5/32" (I believe). I measured mine and it was close to 1/4"!! So, when I put it back together this last time, I checked the fitting that came with the AGR pump, and it was already sized at exactly 5/32"...thought that would solve everything, but no dice...still sucks at low rpms. I've got the 1 3/4" x 8" ram, is very frustrating to have all the "goodies" and still have crappy assist where I need it most! That's why I was hoping that the overdrive pulley could help me out...I'll see if TonyPeebs can machine me one...I'll let you know the results if I get it done.

    By the way, you don't think the PS cooler I installed has any detrimental effects do you? It's a small car tranny cooler by Hayden...I've seen some guys extending their PS Pump reservoir necks to get more fluid capacity - would that help any??
     
  11. BadDog

    BadDog SOL Staff Member Super Moderator Author

    Joined:
    Feb 24, 2001
    Posts:
    7,777
    Likes Received:
    11
    Location:
    Phoenix, AZ
    It's not going to help the low rpm problem to add more fluid, and the cooler won't make it worse. Although, both are worthwile improvements with the added hydro chores. Like I mentioned earlier, I've about come to the conclusion that the only REAL solution to get the performance that I want is dual pumps. /forums/images/graemlins/frown.gif

    On the "still cant use it when I need it most" category... I've been telling people for a while that at idle you can steer, or you can use the brakes, PICK ONE! /forums/images/graemlins/tongue.gif It's a lot of fun /forums/images/graemlins/rolleyes.gif when your nose down, off camber, looking over a cliff, and your tires are pointed straight over the side.... and then you have to hold the brakes hard, get ON the gas to bring the rpms up against the converter to around 1-1.2k rpms, AND THEN you can steer...
     
  12. DieselDan

    DieselDan 1/2 ton status

    Joined:
    Jan 27, 2001
    Posts:
    1,056
    Likes Received:
    0
    Location:
    Vermont
    OK power steering pumps and pulleys /forums/images/graemlins/thumb.gif
     
  13. 86K5TrailBlazer

    86K5TrailBlazer 1/2 ton status

    Joined:
    Apr 24, 2001
    Posts:
    436
    Likes Received:
    0
    Location:
    Orange,CA
    Keith, Re: the cooler I have only read/heard negative remakrs towards staked/sandwich style cools are they restrict flow and that raises temps,
     

Share This Page