Lead additive??

[Guest]

Is a lead additive necessary in the older motors and if so, what's a good brand?? I run an additive in mine, but have no scientific reasoning for using it, just <BR>here-say.

[rocketraider]

Tetraethyl lead (TEL) lubricates and cushions valve seats. It has the added benefit of increasing octane and allowing higher compression ratios. Pure and uncut, it's also nasty poisonous stuff.<P>TEL formulations are available for those who don't mind the risks and hazards associated with handling it . Rubber gloves and goggles at a bare minimum and thorough washup after you're done.<P>The 54 Olds engine probably doesn't need TEL for octane as the compression was below 9.0:1. Most older engines can be safely run on 91-94 octane unleaded fuel as long as they're not really horsed around too hard. You might get into some exhaust valve recession problems if you really dog the car a lot. The heads can be reworked with hardened valve seats which will eliminate valve recession when that time comes. If you hear obvious detonation under normal load, then you need to 1)find better fuel, 2)tune the engine properly or 3)decarbon it.<P>In the meantime, Marvel Mystery Oil or something similar added to gas tank will provide SOME valve lubrication. Not a lot as it tends to burn off at high combustion temps (aggravated by current oxygenate gasoline which burns lean, creating more heat and possible detonation) but enough to stave off problems.<P>But I can vouch for better performance and cooler operating temps in a 64 394 and 69 455 when they get some 110 octane fuel or even TEL supplement in the tank. Then they run like they were meant to run, and smell so good behind them! leaving the smell of burnt high octane fuel in their wake...