Dear Barb and mid-60s Buick caregivers,
Not that I Know. I will ask since I have not drove him long enough to get its oil changed. It was put in last year when I pulled him out of my garage. I have any put 100 miles since I got him running .
If you look at just about any classic car publication, you see a buzz about oils (and oil additives) that contain ZDDP (
Zinc dithiophosphate.) As noted in the Wikipedia article, this compound was discovered in the 1940s and was soon added to lubricants like motor oil. It forms a very slippery film on parts like camshafts. Until recently, all camshafts were of the
"flat tappet" variety. This means that there is a metal to metal surface contact between the camshaft and the lifter. Basically these are two pieces of steel rubbing against each other. Without some sort of lubricant, the lifter will wear down the lube of the camshaft. It is the camshaft lobes that control when the engine valves open and close. If the camshaft started to wear, the valves stop opening when they are supposed to and the engine will start to run rougher until it doesn't at all.
Unfortunately, a small amount of motor oil gets into the exhaust and it was discovered that ZDDP reacted with catalytic converters, effectively "clogging" them over time. So regulators required that the amount of ZDDP in motor oil be greatly reduced. Modern engines use a different system called a roller camshaft that puts a roller bearing in the place of the steel to steel contact point of the flat tappet camshafts. So reducing the amount ZDDP doesn't harm modern engines. However, this is not the case for engines built before the 1990s - like Dusty's.
Around 2005, the owners of small sports cars with high revving engines started to report mysterious engine failures after as little as 6 months after a rebuild. It took a while to determine the cause, but eventually it was concluded that the lack of ZDDP in the modern motor oils had caused excessive camshaft wear. From that point on, there was a race by motor oil makers to come with specially formulated oils for classic car engines. Today there is a dizzying number of motor oil brands with formulations for classic cars. Here is a 6 month old discussion about it on this forum:
http://65gs.com/board/index.php?topic=2931.msg19405#msg19405Indeed, you don't have run over in panic to change Dusty's oil, but probably you shouldn't delay very long either. Biquette's original engine was rebuilt in 2001. In 2010 and after only about 10,000 miles, the engine started to run rough and there was clear evidence of timing errors in the opening and closing of the valves. So modern oils really do damage older engines. Switching to a classic car oil is something you should do at your earliest convenience.
Cheers, Edouard
P.S. There is an interesting post on V-8 Buick explaining of the issues, but that board is still down for an upgrade. I'll post the link when it comes back up.
