So lets say you just rebuilt your original "numbers matching" big block engine for your classic car project. Now that it is rebuilt, you should never have to go through that hassle and stress of dropping in a engine ever again.. right? Well, some new regulations in the contents of your favorite motor oil could be the very cause for damage to your fresh "vintage" engine. This due to the "Evil Government". The U.S. EPA has sanctioned that oil manufacturers remove substances from motor oils that could reduce the life of modern emission related components (mainly the Catalytic Converter)on your car.
The reason this is worrying for your freshly rebuilt big block is that the one main substance that they are pressuring motor oil manufacturers to remove is ZDDP (zinc dialkyldithiophosphate). This additive is a necessity to stop premature wearing and scoring on a number of internal engine parts. They feel ZDDP can leave traces in the exhaust gases which (depending on how much oil a vehicle burns), can cause premature catalytic converter failure and greatly raise the emissions coming out of the tail end of your exhaust. This all makes sense in the manner of "preserving mother earth". But, unfortunately for anyone with a older car the removal of ZDDP could mean excessive (and ultimately destructive) wear on the internals of the engine in your older vehicle (most of which don't even have a catalytic converter!).
ZDDP has been a important additive in oil for many years (I've read it goes back as far as the late 30's-40's). This substance is what creates a very fine film on internal engine parts (most importantly the cam to flat-lifter contact point) and basically sacrifices itself to keep major wear from occurring on the actual parts themselves. Almost all current engines now use roller lifters that do not require this additive or protection. This leaves anyone with a older flat lifter engine out of luck and potentially putting oil in their vehicle that can cause extreme wear on internals.
What we have added to our catalog is our own ZDDP additive that you can mix with today's "stripped down" oil to keep your current (or "new" fancy rebuilt) engine in your older car safe from the threat of this major wear. Simply add the bottle with each 4-6 quarts of oil you put in the engine when doing a oil change. This will bring the ZDDP level back up to a safe margin in which you can rest easy knowing your lifters and cam lobes aren't dying a quick, hot death.
"Why Eastwood's ZDDP formula, when I can get the similar at the local parts store" you ask? Well many of the off the shelf additives you may find at your local store will not have high enough of a concentration of ZDDP in a bottle to bring the levels to a safe point in 4-6 quarts of oil. Therefore, you need to add multiple bottles which now means you are putting a abundance of a unknown oil substance (there is more than just Zinc in Phosphorous in this formula) in with your oil which can dilute the detergents and other chemicals in your oil that need to also do their job. No one likes to be counterproductive, so be very careful when shopping for this type of product at your local store.