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About 80 years ago, while evaluating the effects on gasoline of various heavy metals, scientists discovered that the addition of tetra-ethyl-lead reduced knocking in automobile engines. Lead also had the added benefit of providing lubrication inside the combustion chambers, which was particularly helpful for the exhaust valves and their seats. Because of these beneficial properties, a minimum number of adverse side effects, and its low cost, lead became a staple in gas for nearly 50 years.

All of that changed in the early 1970s, when oil companies began phasing lead out because it was incompatible with the catalytic converters that automakers were required to install. By the late 1970s leaded fuel was becoming quite rare and a few years after that it essentially vanished. This is not a problem for newer cars, which have been engineered to run on unleaded fuel, but can be troublesome for many of the older cars still on the road. While the increased anti-knock properties that lead imparted to gasoline have been addressed with various other additives, the same is not true for lead’s lubricating benefit. Newer engines have been designed to operate without the combustion chamber lubrication that lead provided but older engines are susceptible to certain damage without this lubrication. In particular, the exhaust valves and their seats are vulnerable to accelerated deterioration when an older engine is run on unleaded fuel.

There are two ways to address this problem. The first is with the addition of lead or lead substitute to the fuel in your tank. This creates an ongoing expense and is a little bit of a nuisance but is probably the best solution for cars that are driven infrequently. The second way to deal with the absence of lead is to modify your engine so that it does not require upper cylinder lubrication. This is done with the installation of stainless steel valves and hardened valve seat inserts.

Related posts:

1. Corvette Restoration Tip: Fuel Pump Installation
2. Corvette Restoration Tip: Exhaust Manifolds
3. Corvette Restoration Tip: Wiring Harnesses
4. Corvette Restoration Tip: Understanding Numbers & Codes
5. Corvette Restoration Tip: Door Weatherstrip

Corvette Catalytic Converters, Corvette Engine, Corvette Fuel, Corvette Gas Tank, Exhaust Valves, Gasoline, Lead, Leaded, Unleaded