Nabster

As far as I'm aware what they have out now is a lead substitute that does the same thing as lead in the gas, without actually using lead and thus not giving the EPA a reason to stir a ruckus. It's specifically for the older engines that need it. They have it in the mustang catalogs in the back with the rest of the supplies, and you can get it in most auto stores in larger bottles too.

Oxnard Montalvo

I've been driving some kind of a pre- '70s performance car since before unleaded gas came on the market, and I can tell you I have never had any problems with valve recession or anything else. Nor do I know anyone who has ever had a problem. Save your money for gas.

alz

From what I've read and heard, unleaded gas won't cause any problems with older engines under normal driving conditions. If you are towing heavy loads frequently or doing a lot of drag racing, you could have problems with valves. That being said, I didn't put hardened seats in my 67 Mustang's 289 when I rebuilt it 15 years ago and I've put over 25,000 miles on it with no problems.

Al

kalli

hardened seats don't need lead but the original ones will.
they need that so that then valves have something to nibble on ...

when they removed leaded gas they had additives containing lead, but they're now forbidden and you can buy additives that work the same but without lead.

I'm interested in this discussion as I have no idea if I need it or not. Ie: are my seats hardened or not ...

Kalli

Starfury

What happens is that without lead to lubricate the valve seats, the exhaust valves have a tendancy to stick to the seats under high load conditions, which eventually leads to valve recession. Assuming you're not towing or racing often, the combustion pressure usually aren't high enough to causea problem.

stangimgood

have always used lead substitute in our older cars. just followed instructions on bottle and never had problems. we are not passive drivers. my wife loves to show the ricers that the tires can smoke on the stang and on her jag. i have been told by many mechanics that the way she drives, it's almost manditory to use the additives. i wouldn't mind on the stang as parts are not too pricey, but a v12 jag can cost an armand yourtesticales to rebuild. so i'll just be safe than sorry.....
just MHO

kalli

what does happen when you use the subsitute when you have hardened seats ?

kalli

actually that's a great raed:
http://www.millersoils.net/1_downloa...utes_facts.pdf