A test engine with variable compression ratio is used to define octane rating. It is run against 100-octane 2,2,4-trimethylpentane, compared with zero-octane (n-heptane). This gives a scale for octane. Gas is a mixture no matter who you get it from; but they run their mixtures in the test engine and have it not knock under conditions for which 87, 93, etc wouldn't knock (compared to other gasoline). It doesn't matter how much of what kind of branched hydrocarbons are in it; In other words you might have two completely different mixtures in 87 from one place and 87 from the next place, the only thing you are guaranteed is that neither one of them knocked in the test engine when compression was set for 87. I must assume there is some margin of error that pushes the gasoline to the "Safe side" of 87 (like 87.59 octane or something higher than 87.00) but that is just a guess.

In OUR engines the best safety factor we can use is low temperature. Cold fuel, cold air, water injection, stuff that will slow the rate of combustion down so it doesn't get violent.

 

In my opinion they should've kept lead is gas. It helped reduce engine knocking and it also boosted the octane rating. My dad complains about gas all the time in his 318 Dodge Ram (carb) making his truck run like $#it. It's a all original factory truck. Last year we pulled the carb off and took some carb cleaner to the jets etcs.... You wouldnt believe the green crud/gooey crap that was built up in the carb. Back in the day dad told me they never had those issues.

 

My carbed S10 went to **** also. It was one of the reasons I LS swapped it. I've also been seeing a lot more accelerator pump and float needles sticking in general when helping out some friends on motorcycles etc. you've about gotta run some sea foam in the gas on carbed engines to keep it clean

 

Yes... this past summer I had took a carb off a push mower that I bought to cut the grass with.... your eyes would surprise you all the crap that was built up in it.

 

Gm penetrating oil is by far the best stuff for cleaning that green **** out of carbs.

 

Lead ruins catalytic converters, and they are the only way to clean up exhaust to the extent necessary. The air in our cities is a lot cleaner because of it. So there is a reason the lead is out. Besides that lead fouls plugs and other stuff. So there is a downside on the personal level too.

 

Oh I have something to say about carbs. The air filter and fuel filter, most people don't use the right ones. I am not so sure it is the gas you are seeing "collecting filth" so much as the air quality getting involved. Every carb I ever owned with a proper filter stays perfectly clean when using gas; lawns mower to holley blower carb.

 

It's not always the filter's fault the carb gets "dirty". After time, gas "varnishes" or turns to crud in and around the carburetor. It's the reason for carburetor cleaner, spray or dump-in-the-tank.

 

Gasoline is mostly carbon and hydrogen. Kind of like a short chain, liquid version of charcoal (if we broke the carbon chain chunks out of charcoal and surrounded it with hydrogen to make it stand-alone without becoming a radical)

So what you are seeing in old gasoline allowed access to the atmosphere is, the lighter chains will evaporate first, and the heavier chains tend to stay behind and interact with each other, and form conglomerates. What I am trying to delivery is the message that "charcoal" and "gasoline" are 'dirty' with a wide range of carbon chain assortments, it is un-reacted portions of carbon chains that become "carbon deposits" in an engine.

The solution is to fully seal any gasoline that won't be used soon. i.e. tool maintenance. A carb is difficult to seal so we usually "run it out of gas" when done using the machine. I do this to every tool, 4-wheeler, boat engine, lawn mower; you don't leave the gas exposed to air in your beloved motor.

If you form varnishes, it isn't the fuels fault you let it exposed to air for too long.

if it has good filters and uses good gas, doesn't let it sit for long time between uses, it should stay clean as clean.

 

As usual, you are speaking of ideal situations. A carbureted engine BY NATURE exposes gas to air while sitting. How long something sits depends TOTALLY on when something needs to be used. It IS the fuel's fault; it's the nature of gasoline. Sometimes it might be a while between uses, or it might be all day every day. A car doesn't lead a laboratory experience where its life is scripted to have everything go according to plan. Start speaking in terms of reality, Talon. Not doing so is when you go off the rails, like other times here, and people quit paying attention to you.

 

The reality is I drain the carb everytime I am done with the engine. Even if I am using it the next day, I still run it dry when I am finished. This is my reality.

 

As someone who worked on a lot of pre emissions cars when unleaded was still readily available I can honestly say I never noticed them being any cleaner back before emission systems and efi took over. If anything there were more problems in general because fuel and oil wasn't refined to the point that it is today and both system were more or less open air systems.
You would not believe the crud that built up inside a 10yr old engine. I'm talking about sludge so thick in the oil pan that a putty knife was a regularly used tool. I saw many neglected engines that the sludge was so thick the oil couldn't drain back because the oil return holes were plugged. A high mileage motor back in those days was anything over 100,000 miles. I see engines now that have three times that and no buildup to speak of.

 

And you're wasting your time and in some cases likely doing more harm than good unless it's a two stroke engine that going to sit for months without use. I treat the fuel on anything that's going to sit for more than few months and top off the tank and leave fuel in the line and carb to help combat condensation. Condensation and air exposure are two things I always try to limit.

 

^^^^^Truth!!

 

On small gas engines I find a 4 oz per gallon mix of sea foam prevents almost everything gunk related.

 

yep most common small equipment is two stroke maintenance devices. Many are inside house so there is no desire for liquid fuel in their tanks. Many of them at 20+ years old with original distorted plastic tanks with broken rubber grommets that don't seal well. The point here is to recognize that each persons circumstance is different, and the bottom line is knowledge of the chemistry taking place to prevent buildup of any kind. Not the method of individual users maintenance/storage, which varies from person to person or situation to situation or engine to engine.

Maybe someone wants to read this and tell us what it says (I didnt read it but it resulted first when I googled "how much water does 10% ethanol hold")
https://www.bellperformance.com/blog...tion-Water-E10

If we want to keep water out, here are some solutions for keeping water out I can think of at random
1. wrap the engine or carb with a desiccant (you can put small engine/carb into plastic bags with separate desiccant)
2. Dry boxing, you heat a box to drive water from the air and that is where you are handling and pouring fuels and closing lids
3. Clean dryboxing, same thing as a dry box but with air filters so it functions as a clean room for rebuilding carbs also
4. enter your imaginary way

The inside of some carbs might not really care about whatever water finds the fuel, though. keeping the fuel tanks of equipment full all the time to displace "air water" is far more hazardous and unpredictable when the tanks are "leaky and old" conditions. So it is situational, no "one correct way".

 

and lubricates unhardened valve seats!!!

Just wondering out loud for my own curiosity, is he sticking with a carb to keep the truck original (show truck)? Or ease of maintenance, and/or knows how to work on carbs, but not EFI? Or something else?


Someone already briefly commented on this in an earlier post, but, after long exposure, tetraethyl lead will (ultimately) kill a catalytic converter. OTOH, not sure if kill is the correct wording, but tetraethyl lead will coat the sensor part of your oxygen sensors much quicker, rendering them non functional in a modern, computer controlled, electronically fuel injected vehicle.

Back on topic, I’m assuming you are aware that you can “wash” modern gasoline to remove the alcohol content. If not, there are multiple how-to’s spread across the Internet, just hit your favorite search engine. This assumes also, that non-alcohol, “pure” gasoline fuel is not available in your area. I’m in the south central part of the country, and non-alcohol fuel is available pretty much everywhere excluding large cities/population centers.

The tetraethyl lead is possibly a different story. Any chance either you, or your father are chemist?

Wikipedia has a pretty good write up here:

https://en.wikipedia.org/wiki/Tetraethyllead

To include plenty of chemical formula’s.

OTOH, if a sealed 5 gallon bucket of tetraethyl lead magically appeared on your front door step tomorrow, do you have any idea how much you might need to add to restore your “now washed”, alcohol free gasoline to all of its 1960’s glory? I know I don’t. Also, wondering out loud if a 5 gallon bucket of tetraethyl lead would need any special handling instruction, or if filtered air mask would be necessary? I don’t know.

I’ve taken this restoration of leaded fuel around the long way intentionally. I have serious doubts, even with all the magic he has, that even President Trump could bring back the old leaded fuel we all knew and loved from the late 1960’s and early 1970’s.

 

To clarify, I was the one who said lead ruined converters, and it IS the converter that gets ruined, by lead fouling the catalyst. Leaded fuel will NEVER come back, as long as gasoline-fueled vehicles are sold in this country. Catalytic converters do the job asked of them, and as a result, you will never see lead in gasoline again.

 

You win! I lold all through that post.

If a 5-gal bucket of tetra lead showed up on my doorstep I'd report it to the proper authorities.

BUT if it showed up on my NEIGHBOR'S door, HE might mix it 2-2.2 grams per gallon if HE wanted to be around 100 octane. But he's far less responsible than most of us on this site.

He would probably wear polypropylene gloves and goggles or a face shield while handling it, because he is pretty careful about his personal safety.

 

I had a 6litre in a 2012 2500 4x4. 18mpg on the highway all day long and I never babied that truck.