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Small block chevy throwing PS belts

Discussion in 'The Hokey Ass Message Board' started by mrchevrolet2, Jul 29, 2013.

  1. mrchevrolet2
    Joined: Jul 12, 2013
    Posts: 20

    mrchevrolet2
    Member
    from usa

    I've got a 55 Chevy 2 door post with a 350, slightly built that I can not keep a power steering belt on. Pulleys are in line, stock new NAPA belt for a 350 Camaro. If I tach it up to 5 grand & power shift it throws the ps belt, any ideas? Deep groove pulleys??
     
  2. 40Standard
    Joined: Jul 30, 2005
    Posts: 5,963

    40Standard
    Member
    from Indy

    what type of belt, V or clog type?
     
  3. phat rat
    Joined: Mar 18, 2001
    Posts: 4,920

    phat rat
    Member

    Is the belt the correct width so that it sits down in the pulleys? I used to have a problem with my alternator belt because of a shallow pulley on the alternator
     
  4. ANDEREGG TRIBUTE
    Joined: Jan 1, 2008
    Posts: 1,385

    ANDEREGG TRIBUTE
    Member
    from Bordertown

    Pics if you dont mind so we can see the mounting. Long or short water pump?
     

  5. Power shifting at 5 grand regularly and power steering usually don't go together.
    Chances are that your alignment is off and you just haven't found it yet.
     
  6. Or the pump is loose.
     
  7. mrchevrolet2
    Joined: Jul 12, 2013
    Posts: 20

    mrchevrolet2
    Member
    from usa

    40 standard-v-belt

    phat rat-NAPA stock belt for a 70 Camaro

    anderegg tribute-no pictures, I'm in Canada-car is in Virginia

    31 Vicky-alignment is dead on, checked with a straight edge.
     
  8. mrchevrolet2
    Joined: Jul 12, 2013
    Posts: 20

    mrchevrolet2
    Member
    from usa

    chopped51-pump is tight
     
  9. ANDEREGG TRIBUTE
    Joined: Jan 1, 2008
    Posts: 1,385

    ANDEREGG TRIBUTE
    Member
    from Bordertown

    thats a long ass straight edge.....jk
    since you said 70 Camaro, I guess we will assume long water pump. But there was a change in the mounting and you have to use the right water pump with the right p/s pump brackets. Some had a long bolt that the p/s pump pivoted on that went through the boss on the water pump. Some had a threaded hole on the water pump and that takes a different p/s pump bracket. Ive never mixed the two so I cant say for sure thats the prob, but racing hobby stocks and turning 6 grand and shutting it down for a corner and Ive only had one turn over on me, and thats because it was loose. Hope you can figure it out.
     
  10. Prostreetgasser
    Joined: Sep 8, 2012
    Posts: 11

    Prostreetgasser
    Member

    I used to have the same problem with my big block Chevelle. Six grand and the P.S. belt would fly off. All pulleys were in line. The only way I could prevent it was to go to a "top cog" belt made by Dayco.
     
  11. mechanic58
    Joined: Mar 21, 2010
    Posts: 681

    mechanic58
    Member

    Try removing the belt first before you go hot-roddin it. That should solve the problem.
     
  12. Engine man
    Joined: Jan 30, 2011
    Posts: 3,480

    Engine man
    Member
    from Wisconsin

    I think NAPA belts are made by Gates. I've had many problems with Gates belts. Try a Dayco.

    We had a truck with a Detroit Diesel that started throwing belts after we put a new set of Gates on it. We even had the Gates rep check it and everything was straight and tight. It kept throwing belts and we ran out of new belts so we took a used set off another truck. Those stayed on. When we got more Gates belts, we put them on the truck we took the used set off and that one started throwing belts until we switched to Dayco belts.
     
  13. goodturn
    Joined: Sep 3, 2010
    Posts: 92

    goodturn
    Member

    x2 for the dayco belt.
     
  14. phat rat
    Joined: Mar 18, 2001
    Posts: 4,920

    phat rat
    Member

    While it might be the belt called for, does it fit down into the pulleys or ride up at the top of the grove?
     
  15. Straight edge only works on exactly identical pulleys, with in thousandths and 0 run out. And it only works on one plane. That's important
    The belt doesn't care about the outside edges, it wants to see the centers of the pulleys running true. Also there are a few different thicknesses and angles for belts with corresponding pulleys used across the years, they all have to match.
    And then the other thing is they need to be aligned at 5gs thru the shift, that's when it comes off right?

    My buddy kept inverting his alternator belt in a 1/4 mile pass. 1/8 mile and it would stay on. He swore it was perfectly aligned. We are both looking at it and I see it off, he swears it not. Shows me with the straight edge it's perfect. I made him 2 spacers and the debate starts. After a while I talk him into putting them on. He doesn't understand how to this day and swears it shouldn't but it worked because his belt stays put.
     
  16. scrap metal 48
    Joined: Sep 6, 2009
    Posts: 6,079

    scrap metal 48
    Member

    When power shifting at 5 grand the engine may be moving just enough to throw the belt.. At normal RPMs and shifting it's probably is not a problem...
     
  17. mrchevrolet2
    Joined: Jul 12, 2013
    Posts: 20

    mrchevrolet2
    Member
    from usa

    Called my son, he's picking up a Dayco belt tomorrow. Maybe that's the problem. Thanks
     
  18. chopolds
    Joined: Oct 22, 2001
    Posts: 6,208

    chopolds
    Member
    from howell, nj
    1. Kustom Painters

    The factory, and Moroso used to make deep groove pulleys for high RPM engines. Common problem for belts to fly off at high speed.
     
  19. mustang6147
    Joined: Feb 26, 2010
    Posts: 1,847

    mustang6147
    Member
    from Kent, Ohio

    Isnt this the reason serpentine belts arrived....
     
  20. 1971BB427
    Joined: Mar 6, 2010
    Posts: 8,719

    1971BB427
    Member
    from Oregon

    Why would the engine moving change anything? The accessories all move with the engine, so as long as they're mounted solid anything that is bolted to the engine will move with it.
    Throwing belts is often caused at high rpm by the engine pulling faster than the accessory can keep up, which creates slack on one side of the belt, and they ride up on the pulley. Then a shift suddenly slows the rpm's for a split second, and the belt is thrown. A different V style will allow the belt to sit deeper, so if you're using a A belt, or B belt, you can go one size down and keep it in the groove of the pulley. Sometimes it requires going to an industrial belt supplier and handing them your belt and asking them to match it with a different profile, but same length.
     
  21. TheTrailerGuy
    Joined: Jun 18, 2011
    Posts: 392

    TheTrailerGuy
    Member

    I've had this happen numerous times and it usually ended up being an overly stretchy belt, mis matched pulleys or misalignment due to mounting bracket flex. But... hey... who knows.
     
  22. icsamerica
    Joined: May 23, 2012
    Posts: 62

    icsamerica
    Member

    I had the same problem, My high reving 406 shifts hard at 6k and it tossed almost every belt at one point or another. I tried a double groove PS pump pulley and double water pump pulley which helped. Then I went to the flat style alternator belt form a 85 Camaro but occasionally it still tossed a PS belt. Then I went to a under drive crank pulley. All of these things seemed to have solved the issue but I was not getting enough cooling or Volts at idle with the under drive.

    How is your PS pump mounted? Stock brackets or After market? I determined that my stock PS pump bracket has just enough flex in it for mis alignment when the engine abruptly made the 1-2 shift at 6k to 4K. An after market PS pump mount was another expensive gamble so I gave in and installed an 90's Fbody serpentine system I found on CL for 50$ (that was before HotRod mag did the story on them) ...not traditional but works perfectly.
     
    Last edited: Jul 30, 2013
  23. Mine was caused by a cracked mounting bracket that I couldn't see until I removed the power steering pump.
     
  24. jdubbya
    Joined: Jul 12, 2003
    Posts: 2,435

    jdubbya
    Member

    I have dealt with the same issue in the past... I was told by a friend to run a garden tractor belt, they are stiffer, and seem to stay put, it worked for me, just an idea.
     
  25. mrchevrolet2
    Joined: Jul 12, 2013
    Posts: 20

    mrchevrolet2
    Member
    from usa

    Sorry it takes so long to get back to this, but the wife & I traveling thru Canada so I have to wait my turn at whatever motel we stop at. Anyway my son bought a Dayco belt today and installed it, went for a ride, it stayed on. I've ridden with my son, so if it stayed on for him it should be good, thanks guys!!!
     

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