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Chevy 350 Serpentine to Vbelt Conversion Question

Discussion in 'The Hokey Ass Message Board' started by 1959apache, Nov 28, 2011.

  1. 1959apache
    Joined: Nov 22, 2009
    Posts: 2,635

    1959apache
    Member

    I am ditching my 1992 Astro van serpentine belt setup for something more traditional (vbelt setup) on my 86-92 350 Chevy Block. What I need to know is if I can run the same alternator and power steering pump that I currently have on it at the moment. I know that the water pump is reverse on serpentine belt setups, so that is a must. What else do I need to know before doing the swap? Is there a certain water pump I should use and are the coolant ports the same on the block compared to earlier 350's (I read somewhere they are different)? I have brackets and pulleys ready for installation, just need to make a tally on the parts needed. I am looking for a short water pump setup because that is what my brackets are for. Thanks in advance guys!
     
  2. mgtstumpy
    Joined: Jul 20, 2006
    Posts: 9,214

    mgtstumpy
    Member

    I did the same on my 350 ('90 Corvette) for my '46 Olds. I removed the serpentine system, replaced the water pump with standard rotation [Long] pump, upgraded alternator to 'V' belt drive and added a set of 'V' belt pulleys. Only reason I went LWP was for clearance as I'm also running low mount P/S and A/C and needed header clearance.
    The SBC in my '35 Chevy was easy as it was an '87 motor with standard flow LWP. It only runs a low mount alternator.
     
  3. Pump and alt should both work, but keep in mind there is no offset on the brackets for the serp setup. You will have to align the pulleys on the accessories to the crank pulleys to get everything to run true.
     
  4. 1959apache
    Joined: Nov 22, 2009
    Posts: 2,635

    1959apache
    Member

    this should work for the short water pump conversion as well, correct? When you say that there isn't any offset on the brackets for the serpentine setup, does that really matter if I have a pre-'74 bracket setup (I guess I am not understanding what you are saying)? I am dropping everything serpentine, including the brackets and I have already purchased all new or used brackets/pulleys to get it back to a more stock look
     

  5. 1959apache
    Joined: Nov 22, 2009
    Posts: 2,635

    1959apache
    Member

    btt for the afternoon crowd
     
  6. A good way to check for proper rotation....

    If it has grooves for ribs, it rotates in the same direction as the crank.

    If it's smooth, it rotates just the opposite!
     
  7. Snafu
    Joined: Oct 10, 2005
    Posts: 61

    Snafu
    Member

    Getting things to line up might be tough. I did something similar with my racecar. I wanted to add a cheap-o alternator so I wouldn't have to worry about battery voltage dropping during a race (losing HP), or using a generator and battery charger at the track.

    I was able to get my hands on a bunch of different pulleys from a junkyard. I ended up running a double on the crank and a triple on the water pump. The inner V was strictly crank to water pump only. The 2nd V was crank, water and power steering. I am running a KRC pump so this probably doesn't apply in your case.

    The 3rd V is on the water pump pulley only. I run that one to the alternator. I have a short snout water pump and using the 3rd V gave me enough clearance to run the alternator directly in front of the right side head. I built a small bracket out of scraps and made a tension rod out of an old radius rod. Here are a few pics. It might give you some ideas about how to do your swap.
    [​IMG]

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    [​IMG]

    These are all mock up pictures. I trued everything up and finished all the welding after. 1 1/2 seasons and its working like a charm.
     
    Last edited: Nov 28, 2011
  8. Nevermind on the offset. I didn't realize you were converting the brackets as well. I thought you were just switching pulleys and belts.
     
  9. 1959apache
    Joined: Nov 22, 2009
    Posts: 2,635

    1959apache
    Member

    oh okay cool.

    Even though the serpentine power steering pump rotates in the opposite direction than a vbelt setup, will that pose any issue, will I have to swap the lines from the gear box?

    Does a 86-92 block have any kind of gear that runs the water pump off of the cam (can't remember)?

    Thanks guys for all of the help
     
  10. 1949 caddyman
    Joined: Jun 30, 2010
    Posts: 225

    1949 caddyman
    Member
    from arizona

    Only the LT engine with the distributor on front uses a shaft to drive the water pump.
     
  11. Apache,
    Does the P/S pump have a smooth pulley? I've had a few of those Chevies, and I can only remember them being grooved (standard rotation).
     
  12. 1950ChevySuburban
    Joined: Dec 20, 2006
    Posts: 6,187

    1950ChevySuburban
    Member Emeritus
    from Tucson AZ

    P/S pumps rotate same direction as crank.
    Alternator shaft size is smaller. Can not swap pulleys.
    I'm not sure if P/S pump shaft is same diameter or not.
     
  13. 1959apache
    Joined: Nov 22, 2009
    Posts: 2,635

    1959apache
    Member

    I have grooved, so it should work okay then, I guess I am not thinking correctly lol. I have already pulled the passenger side serpentine bracket and alternator. I was going to work on getting the eyebrow welded on the rest of the way, pull the fender and get that power steering side off so I can, hopefully, swap out the pulleys.
     
  14. 1959apache
    Joined: Nov 22, 2009
    Posts: 2,635

    1959apache
    Member

    So for sure the alternator cannot be swapped? What is the standard size for a normal alternator
     
  15. nev34
    Joined: Jun 20, 2010
    Posts: 2

    nev34
    Member
    from coffs

    I'm doing a silmiar thing. So does a old style chev water pump fit onto a new 350? The LS style? What why does the old water pump spin?
    Thanks
     
  16. Raul jr
    Joined: Apr 7, 2017
    Posts: 2

    Raul jr

    Hello I got question I did the conversion on my 305 engine and it runs a little hot could A revers rotation pump cause it to run hot
     
  17. Raul jr
    Joined: Apr 7, 2017
    Posts: 2

    Raul jr

    I have electric 16" fan
     
    Model A Vette likes this.
  18. 1959apache
    Joined: Nov 22, 2009
    Posts: 2,635

    1959apache
    Member

    Of course, it will not pump properly and therefore, flow will not be what it should. A 396 water pump has the same bolt pattern as a 350, but has a different impeller for more flow. I used this in humid Indiana for better cooling (worked well), but I moved to SoCal and now it is too much and I can't get her to a decent running temperature.
     
  19. Mr48chev
    Joined: Dec 28, 2007
    Posts: 33,948

    Mr48chev
    ALLIANCE MEMBER

    Yep, you absolutely have to have the correct rotation for the belts setup you have.
    I first ran into that mess when the shop I was working at had an 81 or 82 Camaro brought in because it was overheating at road speed and no one could figure it out. Car had had an older 350 from the mid 70's swapped in with V belt drive and the new owner bought a pump for the year model of the car rather than the setup of the engine.
    I never found out how that one came out as I changed jobs about that time and went to work in another shop but month or so later Car Craft or Hot Rod came out with a short Tech article on the subject and the need to have the correct pump for the belt setup.
     

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