I've tried looking this up and everyone has differing opinions.

I have a 1950 Flathead V8, stock, definitely hasn't been rebuilt after about 1980...possibly never. And, now that I've got it running and it's not burning oil and engine seems to run great I now have questions about the gas.

2 questions:

1. It's very hard to find non-ethanol where I live. One place about 20 miles away has it. I go by there every week or two... but i don't always have a gas can (and I'm not driving the truck 40 miles for just gas). Is the ethanol issue only really with not driving the vehicle much and fouling up the carb requiring more frequent cleaning/rebuild? I've replaced fuel lines, fuel pump, rebuilt carb (had ethanol ready parts), so nothing should be affected too much except the engine and the carb. I've read a little marvel in gas helps the ethanol issue as it relates specifically to the carb fouling?

2. My vehicle is running rich. I need to go down a few thousandths on my jets (0.049) at Colorado altitude, maybe more. However, ethanol requires more gas for same mileage... So, if I do use ethanol gas I may be able to keep the same jets in there as the ethanol would counter act the altitude. Thoughts on this logic?

Of course, both of these questions assume I start driving it enough that getting 5 gallons at a time as I go by every week or so is too much of a pain. If using ethanol gas causes more pain in the long run to warrant getting gas 20 miles away, it may just be my answer, stick with non-ethanol.

Any comments/experience/lessons learned appreciated! Specifically for a possibly original 1950 V8 engine.

 

Since you've made the fuel system conversion. I would just buy the corn gas and not worry about it. Use mmo if you wish - or not - and enjoy your ride. These are fairly simple and forgiving engines that don't need pampering.

In my experience, mmo didn't affect performance either way and corn gas is stable enough to endure a few months if weather induced storage. Certainly I empty the lines and carb when tucking the truck in for the winter along with a bit of fuel stabilizer in the tank. Nothing too serious.

Can't comment on the altitude issue since I live at about the 600' level.

 

Leader gas acted as a lubricant in the engine. When an older engine is rebuilt harden valves are usually put in and you can then use lead free gas. Not sure if corn gas has the same effect on the valves but you might be able to put the lead additives in it. Somebody that knows for sure should come along soon and give you the correct answer

 

There's more than one issue to "worry" about if you're so inclined.

Hardened valve seats - with the flatheads, it's my understanding that Henry used good steel, and they aren't really required. It was only in later year engines past the flathead that exhaust valve recession became a problem, maybe because of higher compression or temperatures or lesser quality steels etc. It's also generally more of a problem associated with extended high speed highway use and/or towing that will cause valve recession. So you may not really have to worry about this. Hopefully others will weigh in on this.

Fuel today generally does not have as long of a shelf life because of oxygenates and ethanol, apparently. Fuels containing ethanol are hygroscopic and tend to absorb moisture. In these old trucks a quarter or half empty fuel tank will also act as "bellows" in wide temperature swings drawing in humid air. Then at night it condenses on the colder metal walls of the tank. Over time quite a bit of water makes it into the tank. Also subject to "phase separation" of the fuel. If you can keep good straight gas in the tank, keep it at least 3/4 topped off, away from wide temperature swings it will last pretty good. On a trip where you're running through several tanks, it shouldn't really matter, it's not going to be sitting around. A small amount of Marvel's in the fuel seems to be good stuff and a lot of guys run it. About 4oz per 10 gallons of fuel. Try it and see what you think.

The jetting can be tricky. Your logic is exactly right. If the plugs look good then you're close, but the problem is modern fuels do not "color" the way they did when lead was in the fuel. It is wise to jet down some when indicated but, jet size (for level cruise) also has an important effect on the air fuel ratio the power circuits can provide when under load. In other words, if you jet down too much it will go lean under power/acceleration.

It's OK to run very lean mixtures at no load steady level cruise conditions - but never under power or load conditions. So without using a wideband O2 sensor or something like that it is always better to run a little on the rich side of things. Excessive fuel will wash out rings and dilute the oil in the crankcase. Also keep in mind that carburetors using a power valve or economiser need to be spec'd with a lower number at altitude, usually 1 whole number per 5,000 feet. A vacuum gauge you can read from the cab at different RPM and road conditions is real useful for dialing in a carburetor. When a flatlander gets up high in the mountains the power valve will be stuck open and waste incredible amounts of fuel, very often overlooked.

 

This is IMO only...

Today's fuel is blended for FI engines. The ethanol is supposedly added for emission reasons (not really but it is a racket).

Methanol attracts moisture out of the atmosphere. Modern vehicles have EVAP to prevent this. They also have electric pumps to prevent blend separation. A mechanical pump creates conditions for blend separation (sucking instead of pushing... ).

While the ethanol raises octane, it also presents problems for carbureted engines. If you are not near a seller that offers 100% gasoline (mainly in rural areas with heavy farm usage), your best bet (again IMO) is to add regularly DRY-GAS containing isopropyl alcohol. Years ago, most fuel tanks had a drain petcock to drain any collected water (much like a diesel fuel tank).

Also replace any rubber fuel line with line rated for ethanol (FI low pressure rated). Any rubber say in the fuel pump or carb also has to be ethanol rated.

 

No, there is some logic behind it. Oxygenated fuels are a federal requirement, MTBE was the additive used in the past, but was found to contaminate ground water supplies and consequently has been banned. Ethanol is a "good" replacement as far as that goes.

To be clear, I can't see why adding even more alcohol to the fuel would help anything unless you're running only straight gas, I suppose. It does help keep fuel lines from freezing in the winter, but E10 has made HEET sales a thing of the past, I'd wager.

 

Like I said someone that knows what they are talking about will help. I was under the impression all valves seats were intentionally 'soft' ( if that is a correct term) to absorb the pounding. It wasn't until later they found a way to harden them and still work. Old Henry was a pretty smart guy so it makes sense. I would love to live in CO and have to work out a problem like this because you can't have too bad of a day when you are surrounded by the beauty of those mountains. Hope you figure it out. Have fun.

 

That won't stop you from opining anyway though, eh?

 

There was logic initially but was found over time the methanol caused more damage and did not reduce emission levels as planned. The documentation is available. EPA/Congress has not eliminated it as the methanol industry is lining their pockets. We have the best government money can buy.

As for lead, all the horror stories proved not to be true, Lead was the cheapest way to raise octane in gasoline and refiners did not want to let go of it. Did not matter to then how much the lead damaged the vehicle or us.

ADDED -

Maybe read tech on isopropyl alcohol.

 

That's the thing, I think it's about 50/50 with people saying they are hardened and are not hardened and where the line was (53 and above?) or maybe (48 and above? after the war)... also depends on rebuild which i have no idea about...lol

Thus my confusion. I'm leaning towards just keeping the non-ethanol in there for a while and seeing how much of a pain it is for me to make a 20 minute detour. I'm not driving on the highway or towing anything. And I'm only driving around town and don't expect to take up real high in mountains. I will be using the lead additive though... only because it seems like it might be a good idea.

I live at 6700 feet though, so definitely some new jetting required! 0.051 are on there now, I'm going to order 0.049 and 0.047 and test them out.

 

Well you should provide it. Ethanol does reduce HC emissions, because it's not a hydrocarbon. Big surprise there! I agree ethanol fuels have a lot of problems, but as far as meeting emission controls in that narrow definition it does work. All I'm saying is so long as the feds mandate oxygenated fuels, corn squeezins is a reasonable way to do it. Better than polluted groundwater, I suppose. MTBE is some nasty stuff.

 

Lead additive? Exactly what additive are you using?

It is as simple as this.

Usually only a HD gas engine ( 302/332 - FT - SD Gas) will have hardened seats. They will usually also have sodium filled exhaust valves and rotators as it will be the exh valve that usually recedes.

If you are concerned about the absence of lead, hardened valve seats can be added. There is no mystery.

 

Why should I provide it? Why not provide some documentation as to your position?

GOOGLE busted?...

 

Have run only R90 gas in the stock truck & will continue to do so .The alcohol in the gas causes enough problems in all the implements on the property which requires fuel shut offs, running engines dry & etc.
Yes , hauling gas is a pain but easier than rebuilding items that foul up by the alcohol laced gas .
Have had zero problems w/ the stock truck 239 flattie in 2 1/2 yrs. since completion while running R90 gas .

 

What option do you mean? I said what I thought was correct and your infinite wisdom corrected. But I've change that option you may be correct about the valves. Now I just think you may be a pompous ***.