In what year did engines stop using lead in fuel? I have a '64 C-10 and I was wondering if Lead needed to be added to the fuel. If it does need to be added, is it harmful to the engine if no lead has been used in the fuel for a couple of years. What kind of damage could this do to the engine. I just bought my truck and I haven't talked to the owner about this. I would appreciate any reply, thanks. -Zane
I am no expert on this and I am certain one will come along with an exact answer. The way I recall it was 1973 but some engines had already been made unleaded friendly before that. It is my understanding the lead has a lubricating value. The unleaded engines require hardend valve seats. An older engine may start to smoke more than a new one on unleaded fuel. You can buy some aftermarket heads , have yours worked or add lead to your fuel. Hope that helps... Butch
[updated:LAST EDITED ON Apr-16-03 AT 04:59 PM (CST)]Butch is correct about the lubricant value of lead. Leaded fuel was the single biggest reason the old 283 came out and a newer 305 went in my truck. An engine that's designed to run on leaded fuel, that is forced to run unleaded, will promptly burn the valve seats in the heads and in turn lose performance quickly. It took about 10,000 miles for the admittedly weary 283 to become mostly undrivable. It would ping uncontrollably at anything beyond 1/2 the accelerator and the valve train deteriorated to the point where it was burning more oil past the valve guide seals than it was leaking! Long story short: either have your heads re-worked to accept unleaded gas or put a can of lead replacement in each tank of fuel and plan on replacing the spark plugs every 3 months when the stuff fouls them out!
I rebuilt a 53 chev wagon up about 8 years ago and asked around about unleaded fuel problems at that time, because I wasn't doing the head just the bottom end of the 235. I was told that the lead build up on the valves over time should be sufficient to allow you to run the engine without worries on unleaded fuel. I ran the engine for 5 years before I sold the car, with no concerns using unleaded fuel. I suppose a V8 might have more strain on the valve train, hence more problems, but many of the guys in the vintage chev club I was in just ran the unleaded without special precautions. That is my meager experience for what it is worth.
I thank you all with your help about my truck, it was very much appreciated and it should help me a lot. Zane
