Measuring crankshaft oil clearance on a Chevy small block | Redline Update - Hagerty Media
The old adage, “cut once, measure twice” rings true for Davin in this week’s Redline Update as he measures for oil clearance before the crankshaft on our Chevrolet 283 small-block V-8 is reground.
Davin’s been rebuilding engines too long to simply trust the numbers that come from the factory. So today, he’s putting in some extra effort to verify that everything on the rods and main bearings is as it should be.
“These bearings are 10 thousandths [of an inch] oversized, meaning this diameter is going to be 10 thousandths smaller than it would be from GM, let’s say,” he explains. “What I need to do is verify this number and give [our guy] a number that allows for oil clearance. Oil clearance is simply this: You have to have room for oil … oil lubricates everything … So if this diameter and the shaft diameter going into it are the exact same size, this isn’t going to turn.”
After Davin pulls out his cylinder gauge and gets into the minutia of the process, he offers his RockAuto.com tip of the day: “Measure every one of them. Don’t assume that because you bought the bearings from the same company they’re all marked correctly, that the measurements are the same, because they might not be. Stuff happens. And write everything down so you have a permanent record.”
With his work done for the day, Davin gives an update on the Buick Straight-8 by showing us its final destination under the hood of a 1951 Buick Super convertible. Of course, he isn’t content with just showing us, he takes the beauty for a drive on a gorgeous spring day in northern Michigan.
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