VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 adding lead to the fuel

Some of the old timers that own cars in the 30s and 40s say they add lead to their fuel because the unleaded fuel is hard on the valve seats. true or false?

False

This has been discussed and if I recall correctly the consensus was that the statement would be true in that the unleaded fuel would be harder on the exhaust seats. I think the controversy comes when in determining just how much harder (on the valve seats).

Several old time experts suggest that it isn't necessary and cite the cost (in trade off terms), as well. If I had the head already off, I think I would do it. But if the engine is buttoned up, I don't think I would unbutton it for that purpose only. If that makes any sense.
Charlie

BTW: When I took my cylinder head in to have it done, the machinist said it wasn't really necessary unless I was going to drive it a lot. I know that "a lot" is a relative term but we were on the same page. I don't expect to drive it much more than 2-3K a year. No A/C. You know.

BTW2: If I got this all wrong then somebody will undoubtedly straighten us/me out.

As you will recall, we have discussed this subject many, many times in the past (due a search on CC II and you will get tons of hits). Anyway, the answer is false! A lead additive is not needed on the older low compression engines and to do so is a complete waste of money. Cars in the early 1930's and prior ran on unleaded gas when they were knew. A lead additive for the newer vehicles is not needed either since they will perform just fine without it. Additives are just another gimmick for taking money from the consumer.

I've put tens of thousands of miles on various engines made when lead was in gas using unleaded gas and never had an issue with damaged seats.

GREAT !! I didn't want to start buying an additive every time I gas up anyway. THANKS

Wawuzit....Fill up your gas tank with Jack Daniel's,that good old (home town)Tennessee sipping whiskey. Then if your valve seats burn you won't care anyway.GOOD LUCK.

Sounds like a plan to me. There's still a few moonshiners around if times get hard (harder).

WAWUZIT.
I just want to point out that in your initial post you made a statement. Then you asked if the statement were true. It is TRUE. It is true because some old timers DO make such statements. Nonetheless I assumed that your intent was to ask if unleaded gasoline was hard (read harder) on the exhaust valve seats than leaded gasoline.

I don't belive that there is absolutely no difference between the two fuels regarding the valve seats. I believe that there is a slight negative impact to be realized if one drives the engine at highway speeds for extensive amounts of time and distances and accumulate a little upwards of 60K miles over time.

I believe too that the difference is so slight that by the time you reach 60K or so on a babbit bearing engine it may need a minor overhaul anyway, i.e. valve grind, rings and rod bearing adjustment, etc, as appropriate. So there is, after all, nothing much to really to worry about, is there. Hardened seats can be installed when needed.

I realize that others may have good reason to say that the statement is FALSE when assuming its intent. I respect that. But technially speaking, I "stick to my guns."
Best,
Charlie

BTW: I could be absolutely wrong here. It is just my opinion. Nothing more.

It will be easy enough to tell if your valve seats are "sinking in" as the exhaust valves will get tighter and cause the engine to run rough after it gets warmed up. This would require adjusting and loooseneing the adjustments frequently.
I have never heard of anyone having this problem.
My 1950 has 55,000 miles on it. The last 35,000 miles have been put on with unleaded gas and at Interstate Highway speeds and the head has never been off......they couldn't do that years ago with leaded gas. We would be grinding valves from 25,000 to 40,000 miles. Unleaded gas is actually better for the valves because the lead deposits are not there to keep the valves from closing completely and causing them to burn.

Gene, maybe so but we're talking about the exhaust valve seats not the valves themselves. Just ask youself how many do you think, that if suddenly they had a choice between two pumps next to each other, one regular leaded gasoline and the other regular unleaded gasoline, how many of us would be lined up for the leaded. Something to think about.
Charlie

Notice in my first line I said valve seats.......The valve seats in the "seat" in the head. The seat can become too deep after many valve and seat grindings. If the seat becomes too deep from too many grindings then its time for new hardened seats. This can happen with leaded or unleaded gas.

I started using unleaded in my cars when leaded was still available.

Unleaded also makes the exhasut systems last longer, eleminates the lead (which is acid) from getting in the oil and attacking the bearings, no more lead fouled spark plugs and on and on.

Lead was only used to slow down the buring rate of the gas. Thats was back in the days of poor refining methods. It was never intended to lubricate anything.

I had the unfortunate luck of taking the head off of my 216 after about 23,000 miles after an engine rebuild. The head does not have hardened seats in it. The car was driven at 65 mph for many of the 23,000 miles. The valves were great as was the valve seats. Obviously all of the 23,000 miles have been done on unleaded gas.

dtm

Then, it seems, that the answer to the initial statement and its intented question, is that unleaded gasoline is actually easy (read easier) on the valve seats. Is that what the proponents of/for unleaded gasoline are saying?

I'm trying to remember what all that hoopla was years ago when we first learned that lead was being removed for gasoline. I thought that, at the time, consensus was that removing the lead was a bad thing for old car engines.

Now some are saying that leaded gas is bad for the engine's valve seats and that unleaded is better. It's a puzzling dilemma.

Charlie

"It used to be that before the addition of lead, gasoline tended to pre-ignite or detonate, causing a metallic 'pinging' sound, a situation called engine-knocking, that damaged the engine. Tetraethyl leaded gasoline changed that. Not only did leaded gasoline withstand higher compression environments, they also lubricated the inside and valves of the engine, protecting the valve seats from erosion."

The above is from the "Wise Geek" or something like that.
Charlie

BTW: How 'bout them apples."

Way back when lead was being removed from the gasoline lots of "experts" claimed that the new unleaded gasoline would ruin the valves and valve seats in older vehicles since the leaded gasoline provided lubrication to the valves. They had many of the car hobby population buffaloed and scared to death. The "worst" didn't happen and it turned out that the older vehicles ran just fine with unleaded gasoline.

Our 1969 Impala has used unleaded gasoline for decades and with almost 200,000 miles of running on unleaded gasoline it has never had a problem. The same is true for my 1972 Cheyenne and my 1968 GMC....no problems there either and my '68 GMC has run for over 100,000 miles with no issues. The only time it did burn a valve is when it was running on LEADED gasoline! Same is true on my '51 Chevy....no problems at all after using unleaded for over 20 years.

Now, that stupid, worthless, garbage Ethanol is a different story! Our 1984 Oldsmobile absolutely hates that crap and in hot weather it vapor locks constantly.

"...lots of "experts" claimed that the new unleaded gasoline would ruin the valves and valve seats in older vehicles since the leaded gasoline provided lubrication to the valves."

JD, I done believe you have hit the nail on the head!
Charlie

From July 2011 in Australia,ordinary octane un-leaded will no longer be sold,and we will be forced(by a combination of government greed & tree hugging greenies)to purchase either premium un-leaded(up to $1.40/litre Australain,or rubbish E10 ethanol mix.
BP(aren't they a nice company!)are now in the process of coming out with an E85 blend and in conjunction,Holden are looking to build a new engine to take the new fuel.Looks like another way to push older cars off the road.

<Posting Deleted>

It's not that I disagree with anything that was posted here... it's just that we try to keep politics out of this forum.

somebody been drinking steves moonshine again..

As an update to my previous posting please note that the key words in my statement are "experts claimed". Actually, it was found that the leaded gasoline lubricated nothing.

But its proved to be a good money maker for those who sell an additive that is claimed to contain lead AND DOES NOT

Man, you are so right on that one! Lots of dudes are wasting their money on lead additives and they are not gaining a thing.

I think the dudes that buy the mouse milk additives also believe that the oil companies and car companies were in cahoots to suppress all those carburetors that got 50-100 mpg. Wonder if they still think that they have done the same with the fuel injection systems? Some people will believe anything even if it is not logical. Of course most don't know what logic is because it is not even discussed in modern schoolrooms.

since we are already talking about it. what year did lead come into fuel and what year did they take lead out.