Buick Cam Thrust Bumper
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Stuff you can do to prevent the camshaft from having too much end-to-end play in it on your Buick 400, 430, or 455. These concepts apply to other Buick V8 engines as well - 300, 340, 350 - though the exact details may differ.

There is some info about these types of modifications on the Buick Performance site, as well as a good bit of detail in the book Guide to Buick High Performance Engines by Steven L. Dove. I bought my copy of the book through either Poston or TA Performance a long, long time ago. You can also try Amazon. I got the basic idea from the books, and the specifics from Jim Burek while I was talking to him about a rebuild kit for my 430.

Basically, you drill and tap a 1/4-20 hole in the end of the cam thrust pad on the inside of the timing cover. Ensure it goes all the way through into the water pump area. Cut a small length of 1/4-20 brass all-thread to fit into the hole. Round off one end of the all-thread to use as the bumper, and cut a slot in the other end to use to adjust the bumper depth. After you install the cam and timing gears into the engine, temporarily install the front cover without a gasket. Adjust the can bumper to just touch the cam sprocket. Remove the front cover, fill the hole in the water pump area with JB Weld, and let it cure. Later, when you install the timing cover with a gasket, you will be left with just the right amount of clearance between the cam sprocket and the cam bumper. If needed it can be readjusted later by melting out the JB Weld with a torch and doing the adjustment. Luckily, most cam and sprocket sets will be about the same dimension, so even after a cam swap, odds are this will still work right without any adjustment.

Here's the piece of brass 1/4" x 20 "all thread" I bought at my local Home Depot to start this project. I cost just a few dollars.

BuickCamThrustBumper01.jpg (841071 bytes) BuickCamThrustBumper02.jpg (713226 bytes)

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Page last updated 01/02/2009 01:51:39 PM