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pulley ratio with edelbrock waterpump

Discussion in 'Shop Talk' started by dwj, Apr 27, 2009.

  1. dwj

    dwj Member

    Could not find anything in searches on this item. I have KC big block with edelbrock waterpump and the crank to waterpump ratio is 1:1. I called Edelbrock today to ask their opinion on changing that ratio to increase the flow of water. They informed me that they recommend the pump run at .7 that of the crank. (cavitation a concern)

    Has anyone trialed different pulley ratio's with an edelbrock pump? Wonder if I slowed my pump down if it would cool better?

    Not sure if I am going to have an overheating problem this summer, just trying to figure out my options if I do.
  2. 427HISS

    427HISS Member

    I'll be building a 527 cu. side oiler and I've done some research.
    Supposedly,.... the Edelbrock pump increases 40% over stock. With the "March" pulleys, they sell a kit for cobras. kirkham has also figured out what sizes are needed for our cobras. We need to overdrive the pump by 15%. Dave Underhill has been all through this. Maybe he'll check in. :mrgreen:

    I believe with even a stock ratio, if you have your colling system is working properly, there should not be an issue. When I bought a Spal fan & shroud, I did not get over 2010 degrees with my old 428, and that was in 95 degree temps in traffic.

    We'll see how my new monster motor does. :wink:
  3. undy

    undy Member

    Up to 527 now Kev?? You need to make up your mind... 482? 496? 527? I'm not sure that Genesis' iron block's clearanced for enough stoke to get you to that CI.. I'd thought the Shelby aluminum block was the only way to go for that monster 4 1/2" stroke. (that's what's required for 527) I'd hate to see that dual plane intake cause that motor to fall on it's face at 5K RPM.

    Back to the pulleys..

    I'm running an OEM 1 row steel 6 3/4" OD crank pulley with a 6" single row aluminum March water pump pulley. That equates to a 12% overdiven waterpump.
  4. 427HISS

    427HISS Member

    Yeah, I thought with the machine shop making a very cool billet air cleaner assembly (and other products) that replacing the 427 for a 527,..... would look cooler. :lol:
    I'll be using the single Victor intake. 8)
  5. Kevin, I can't locate your partners number, any word on when to expect pipes, KC called getting close to buiding.

  6. 427HISS

    427HISS Member

    Hello Wendell,
    Usually, it's 4-9 weeks depending on the muffler supply. Below is Ron's number & I'll also call him. Since these are custom made and not cookie cutters laying on the shelf, it just takes a little more time. You'll be very happy with them.

    Tell him he's hard to get a hold of because he's so OLD and doesn't get out of bed until noon, then back after the cows come home, at 5:00 pm. :lol:

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