Fuel for old tractors - Lead?

[Qapla]

the best thing for those old motors is to find gas with out E85 in it.but thats like looking for a needle in a haystack.

Guess I'm glad I'm not in your neck of the woods. Around here, you are doing good if you CAN find E85. However, all the gas has 10% Ethanol.

Running the "modern" gas will probably not hurt the motor, as long as you aren't working the tractor all-day-every-day. However, I will probably result in a premature need to rebuild the carb if it has rubber seals in it. If it is old enough to have leather seals, the alcohol doesn't do them as much harm as it does the rubber.

 

[DJ54]

A machine shop operator where I had the head for my '64 Ford truck 6 cylinder suggested using Marvel Mystery oil in the gas tank. Works great in older lawn mowers too, that the valves may stick when using unleaded gas.

We're still fortunate here in my area, to get 100% gas. You just have to buy it at a company named station. BP, Marathon, Sunoco, etc.

Alcohol pretty well wreaks havoc on anything neoprene in carbs. I know it took more than several thousand accelerator pump seals out of many early carbs... Mine included, in my '74 Chevy truck.

 

[Bigkrank]

Lot of us around here go to the airport and get 100LL avgas. It's all I've used in old tractors and older small engines/chainsaws for quite a few years. Doesn't varnish either.

 

[Reg]

As I understood it the issue is "soft" valves and/or valve seats.
The lead additive somehow softened the blow of the valve hitting the valve seat, i.e. its benefit was mechanical not chemical. It was an anti-knock agent too.
BICBW.

I used a lead substitute additive in 80s/90s boats, which were supposedly 5 or 10 years behind their car/truck equivalents - at the time.
I haven't run a boat in a long time, so haven't looked for the lsa at Wally world lately.
I may still have some, I'll dig around and see what I can make out of the label.

I think there were some places offering head re-builds with hardened valves and seats - which were claimed to fix all things (-:
I never looked into that fully,,,,, it may be worth some research.

 

[SandburRanch]

I don't know what all the hype is about leaded gas. Natural gas and propane engines ran just fine without lead and the valves lasted a lot longer than engines running leaded gas.

 

[Reg]

I don't know what all the hype is about leaded gas. Natural gas and propane engines ran just fine without lead and the valves lasted a lot longer than engines running leaded gas.

The "hype" has history.
I can't get the details exactly right, but if you try a search for Dupont, General motors, and tetra-ethyl lead you should get the "story".
At least some modern rendition, courtesy of wiki and its contributors.

 

[GaryCrowell]

I personally think the issue is overblown and you could probably run regular unleaded gas in an old tractor without noticing any ill effects. On something that old chances are something else is going to break long before the lack of lead affects anything. I'd be more worried about running gas with ethanol in it, but ethanol free gas is pretty easy to find in my area if you look around. Several stations have signs boasting ethanol free gas and that's where I buy gas for my chainsaw and other small engines.