Story by Phil

“We would remove the spark plug and pour in a small bag of ground up walnut shells…”

In 1953 Buick introduced the V-8. Commonly called “The Nail Head Engine” 1953-1966. It had a high compression ratio and dome pistons. If it was driven conservatively carbon would build up in combustion chamber. When a piece would break off you would swear the engine had a rod knock. This became a common problem because most of the Buick customers didn’t use wide open throttle much. Liquid chemicals introduced through the carburettor would dissolve the loose piece but not clean up the combustion chamber for a long-range repair. This was the where the Walnut shells come in.

We would remove the spark plug and pour in a small bag of ground up walnut shells. Insert an aerator into the plug hole and apply air pressure. As the walnut shells swirled around they would scour out all the carbon. Then a vacuum attachment was inserted into plug hole to remove shells and carbon.

This worked very well with one exception. If you left any walnut shells in the cylinder when the engine started it would break a piston. We got so we would hold our breath, cross our fingers and say a prayer.

Phil