yankeesfan

What do you do when the car takes leaded gas and you can't buy that. I read about an additive and it takes about a bottle to a tank of gas. Does that sound correct? Thanks for not laughing.

J-(Chicago)

http://www.truckcustomizers.com/prod...FLL100.01.html

1971 and earlier may need a lead additive to help protect the valve seats.
Not a huge deal to run without it if you don't beat on the car or take it on cross country trips.

jensenracing77

there are many thoughts on this. all you really need to do is add about
1/2 Qt of automatic transmission fluid to your tank of gas at fill up. many people say that you should just forget about it and drive it. i have even seen people go 10s of thousands of miles with no problems. you can also use marvel mystery oil but it is a little more money.

yankeesfan

Really transmission fluid?? Did you mean that some people do not add anything to the gas, just run unleaded?

jensenracing77

many people don't run any thing and don't have trouble. and yes, surprisingly ATF will lube the valves good enough. it is also a good additive for older diesels that don't like today's dryer diesel fuels but that is another subject.

Redog

I used "Gunk" lead additive.

$3 a bottle at AutoZone

Yellowstatue

We don't add anything to our gas and the kid's '68 350 (regular unleaded) went to Alberta and back to too close to Toronto in 2005,7000km, and she has had that car eleven years now...the wife's '68 400 (premium unleaded) has never had additive in the past 27 years or so...my '69 GMC 350 (premium unleaded) has not had any additive for the past 12 years ...so what we are saying is that we are too cheap to buy additives and we still have our valves

csstrux

I used to occasionally use ATF, otherwise pump and go. Never had a problem. I was never running a high performance engine, and rarely treated them that way, so have no personal experience there, but day to day driving and what not, you should be fine.

ThyPlumber

Yes and no on the leaded gas. It will burn the seat if you do not use it. Been there done that, also try putting the car on a dyno with and with out, it makes a difference in performance numbers. I would suggest buying some 100 LL AV gas, usually cheaper than race gas. Or even easier pop the heads off and have a local shop put the hardened seats in and a multi angle valve job while your at it. Problem solved for a couple of hundred bucks. The valve job will probably wake the motor up quite a bit.

old98owner

A question and a word of warning about having the valves redone...

When these cars were new mechanics would caution you about just having a valve job without replacing the crank bearings. Why? The rational behind this was that the increased compression would put such a strain on your bearings that they would soon go out.

In other words: All of the engine was worn, not just the valves, so you might as well repair everything at once.

Now we are talking about cars from about 1960 with 80,000 miles or so on this here, not high compression engines from the late 1960's. Still, is this advice good or is it just an old tale? Did engines improve over the decade to the point that a valve job did not place undue stress on the crank bearings?

ThyPlumber

I would just do the heads and forget it. My recent project started out like that, might aswell replace this too while I am at it. I have spent 15K on parts so far and put more labor in the car than you can imagine, and still not finished. The car is for sale now, and I am going to lose my butt on the deal. I would just fix what needs fixing is my advise.

MN71W30

Most of these old cars don't get alot of daily use. I think if you really think you'll put a ton of miles on the car and had the heads off anyway I would consider it. But for the last 10 years I haven't had seats installed on any of my heads and never had an issue. I like some of those home remedies, I'll have to read up on that.
JMO
Dave

bigoldscruiser

When I was a teenager (many moons ago) my boss bought only DeSoto's and used only Amoco white gas (no lead) and never had any trouble. Why would it be any different now?

Rdrokit

I usually just have the heads fitted with harden valve seats and not worry. About doing valves and causing the bottom end to go......if the bottom end is that worn it should have been rebuilt when the heads were done

yankeesfan

We don't plan on driving it much and the engine was just rebuilt. We talked to the current owner and he said he has been running unleaded through it and it needs no additive so maybe he already did the heads. We are going Wednesday to look at her and hopefully bring her home. Thanks for everyone's input and help!!

69OldsCutlassS

leaded gas, whats that? lol

69OldsCutlassS

By the way I was lol not at the question but at myself, by the time I was born leaded gas was a thing of the past, I have a 69 and never knew about leaded only, I have only seen unleaded only.

oldsonharmont

I had an old engine builder tell me that valve seats were 'hardened' by simply holding a torch to them for a little while. I'm not sure if they were in the car or not, but that's all it took according to him.

Hydro462

I ran unleaded 93 in my hi compression 64 Pontiac 389 for years without any troubles.. Very successfully performance wise too. I know many people out there who have done the same.. Most of these additives today are nothing but alcohol. Todays gasoline already has enough of that...

I've used tranny fluid to free sticking lifters buy adding a 1/2 qt to the oil but never used it in the gas and I've used a pint of brake fluid in my hydro to help swell the seals. That's interesting putting tranny fluid it in the gas.....

88 coupe

Use unleaded gas.

Norm

88 coupe

And hope no one notices the blue smoke from your exhaust.

Put it this way: If oil in the combustion chamber is a good idea, why are "oil control rings" used on the pistons?

Not exactly: Some people waste their time and money on additives. The rest of us use the gas that comes out of the pump.

Another myth. It can, but only under extreme circumstances.

It is.

He is right.

Norm

88 coupe

It was called "white gas" because it was clear, like water, and commonly used as a solvent/cleaning agent. Because tetraethyl lead was/is poisonous, coloring was added, as part of the lead additive, to identify it as such.

Not quite that simple, but it is how they were done at the factory.

Norm

wmachine

There are obviously different schools of thought about this. Personally, I've seen and heard enough to be convinced which is right. I won't even get into it.

But the point I'd like to make is this: Using a lead substation is cheap insurance even you don't believe it is needed.

csstrux

GOD I'M GETTING OLD!!!!! Had too

82 Grocery Getter

WOW! This absolutely... positively the FIRST time I've EVER heared of adding ATF to the fuel OR the oil!

jensenracing77

i am of the school of not adding anything but 1/2 Qt of ATF won't make it smoke. i took an engine apart that had ATF ran through it for over 50,000 miles and the heads looked great. no build up in the ports or anything. it was very clean in the combustion chamber. of course i had the seats updated while it was apart.

82 Grocery Getter

ATF added to the fuel, the oil, or both?

Thanks,
Chad

jensenracing77

just the fuel.
i have seen people do it in the oil to help clean the crank case after a blown head gasket. they will add a little and run it for a few minutes and drain it. i have no idea if it does any good. if i was to flush one i would just use oil. i think the theory is that ATF is a detergent and it will clean good. the only thing i personally have experience with is the fuel. and especially for older diesel engines because of the dry fuel causing injector pumps to go out.

dingusboy

Has anyone used an actual "lead" additive? Not a substitute for lead but actual lead.

wmachine

Yes, I have, but it is highly toxic, and not necessary to get upper cylinder protection. "Real Lead" had real lead in it, surprisingly. There are safer alternatives, so why take chances.

Yellowstatue

I thought that lead was only toxic if it was moving really really fast!!

wmachine

That's lethal, not toxic!

Texascarnut

You don't worry about it! Leaded fuel has not been commonly available since 1974. A total ban on leaded fuel went into affect in 1996. So what ever the car may be, it's been running on unleaded fuels more than likely since 1974 and certainly after 1996.

While lead added a certain amount of lubricating properties for valves its primary purpose was the elimination of spark knock, i.e.; boosting the octane rating. The possibility of valve seats being damaged on an engine previously using unleaded fuel is pretty darn remote. Many "myths" have circulated about ruining pre 1974 produced engines with unleaded fuel. Typically the engine will die from other causes before valve seats cracked.