Checking the Cam Lift

Discussion in 'Wrenchin' Secrets' started by Gary Anderson, Dec 2, 2019.

  1. Gary Anderson

    Gary Anderson Well-Known Member

    I bought this '68 Riviera (w/ 430) and the PO claims the engine was rebuilt before he bought it, but has zero records of it. From all outward appearances, I don't doubt it: Edelbrock Performer intake, Edelbrock carb, some chrome on and in the engine bay, completely new aluminized mandrel-bent exhaust system... Looks like somebody actually spent some money on it. There was even a pair of "430-4 Stage 2" valve cover stickers in the glove box (unused/new). The engine doesn't smoke at all, and lopes like it's got a cam in it, so I'm pretty sure it has been rebuilt. What I don't know is what's inside the block - cam, pistons, overbore, or even if the block was original to the car. (I'll try to get the block and heads codes tomorrow.)

    My question is about using a dial indicator on the rockers to deduce what the cam lift is. If I pull a valve cover and turn the engine over by hand so that I get full lift on an intake (or exhaust) rocker, will a dial indicator give an accurate cam lobe lift measurement - considering that the lifter may absorb part of that lift.

    Any other suggestions as to getting some answers without too much digging in the engine?
  2. philbquick

    philbquick Founders Club Member

    I don't know that series of engines (the only one I've never owned) but, if your dial indicator is on the push rod side you shouldbe able to determine the exact cam lift. You should also get a general idea of duration by looking at the damper timing marks and the valves as the exhaust closes and intake opens. You should be able to see if there is any over lap between intake and exhaust.
    Gary Anderson likes this.

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