Could somebody please explain to me why or why not you should be putting lead additive into your gasoline? I'm running number five heads on my classic olds and I didn't know if I add lead additive, it would help seal the valve seats better.

 

Later heads got around the removal of lead from gasoline by installing hardened valve seats. In fact, if you have machine work done on an old set of heads the machinist will usually install hardened valve seats (at least on the exhaust side).

DOH! I guess I misread your post.

 

What year and model is your "classic Olds"?

 

As am I.

Lead additive alone makes the engine run worse. I have tested several combinations over the years. You want an octane booster with MMT.


That's the best of the readily available.


And that's close enough.

 

Matt, as you intimate, lead helps cast iron exhaust valve seats last longer.

But what years of unleaded gasoline use have shown is that heavily-loaded engines are the ones affected most. Lightly-loaded engines can go most of their life without significant seat recession.

If you have a current problem or whenever you rebuild your heads, get inserts. Otherwise, if you are not towing with your car or using the engine in a boat, don't have concern about using a lead-replacement additive.

Gary

 

Tetraethyl lead (TEL) is what used to be in fuel as an anti-knock agent to raise octane, overtime It was also found to help prolong valves and seats. The reformulated fuels used today compensate for that in most cases and hardened seats help for engine used for towing or high torque applications. I've found that no additives are required over the last 20 years.

 

American,/Amoco has sold premium gas without lead since the '60's. We ran Amoco Premium (unleaded) almost exclusively and never had a problem without hardened seats specifically on Olds and other engines for many years and miles. As stated heavy duty use such as towing may be different.

 

My experience in the business is that Olds heads rarely if ever have valve seat issues. To be honest with you not many engines really do unless they are run very hard. I would not worry about it just make sure to run a good quality name brand fuel and it will be fine.

 

That's what my uncle told me, that is good information thank you.

 

Thank you everybody, your comments really cleared things up for me.