VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Gas lead additives

All of a sudden I am finding new issues after fixing the transmission oil leak.

What is the consensus about lead additives?

1930 Coach . Should I go ahead and use them or what I have around the garage? This has never come up before.
I think the exhaust valves were redone when I first bought the car 8 years ago.

Don't waste your money on "lead" additives.

There was no lead in gas in 1930 unless you bought the pemium which was called Ethyl gas back then and cost more money.
Ading lead was a cheap way to increse octane.....increasing octane made the gas burn slower and was desrieable in high compression engines which Chevrolet was not.

I don't want to step on any toes here and hope I'm not.
With due respect, and the caveat that I can be wrong...
Leaded gas was not commonly used yet in 1930 but... it was common to do a frequent valve job. Sometimes annually at least. Most of those valve jobs went by the wayside when leaded gas was used.

Here's why:
When valves get hot, micro welding occurs between the valve face and the seat. This tears tiny pieces out of the face of the valve eventually destroying it's ability to seal properly. Hot gases start to seep by the valve and eventually the valve and seat start to burn out.
Lead in the gas left a white oxide deposit on the valve face and seat that slightly separated the 2 surfaces and prevented that micro welding.
Harder valves and seats or inserts fixed the problem without the lead.

After lead was gone, some gasoline had a phosphorus compound added that left a darker phosphorus based deposit on the valves that accomplished the same thing.
Good "substitutes" that specifically say they protect valves do this same thing.

So...
If your engine has new valves and hardened seats... you are good to go without an additive.
But if it has original valves and seats and you aren't sure if your gas has the phosphorus additive... is the cost of a few bottles of a good gasoline additive that specifically says it "protects valves" too high?
It's the valve protection you want. Not the octane improvement. And it's up to you.

I do not want to get in a debate on the value of "lead" additives in low compression engines.

I fully understand that the following is anecdotal and not scientific. I can expand the discussion to a more scientific level if it is necessary.

I have driven 1931 and 1932 Chevrolets for over 50 years. The vehicles are basically stock with stock parts. Don't know the total miles but it is well over 10,000 miles. I have never used an additive in the gasoline except for a little ATF or oil occasionally to reduce the sticking of intake valves. I also don't drive them like a "grandmother". I have never had any problems with valve erosion or had to do a valve job even on engines that I have not rebuilt. I have also driven an original stock 1951 235 cu in engine driven thousands of miles without additives or any valve problems.

There are plenty of higher compression engines with "soft" valve/seat metal that might benefit from additives or part replacement. However they produce much higher valve/seat temperatures than the low compression engine that is the subject of Bauer's inquiry.

THANKS TO ALL.

After we fixed the transmission leak problem, other people suddenly brought up the lead additive question. One thing I think is certain is that if you only drive the car for 2-300 miles, for
a year, it matters little. The same as do you use Castrol 10-30 or Walmart oil? Matters little as there is so few miles I will put on the car. But I did want to ask.

What a bunch of terrific answers.