OLD GAS!!! Dangerous For your Old Engine!

Don't use old gas in your old engines! It will and does cause damage to the valve guides and heads. We need to use fresh fuel and a top-end lubricants, in our old cars and Ferrari's, even more so!

MMO-Marvel Mystery Oil or 2-cycle oils, in the fuel at proper ratios, will prevent damage. I've done this for years in classic and antique vehicles.

I like to watch "Jay Leno's Garage", and he had this happen to his rolling chassis Duesenburg. Watch this clip and see what Jay and his mechanic, have devised as a remedy for this, on his Duesenburg. I don't agree with the reccomendation of ATF, as a lube. It's not the right kind of lube and is not designed to be combusted and has other additives that cause other problems of deposits, when they are burned.

Watch this clip from his site. There is a 15 sec. GM Cadillac Commercial, before the story starts.

http://www.jaylenosgarage.com/video/index.shtml?vidID=126269

Hope this saves some grief for someone.

Ciao...Paolo

 

Cheers Paolo
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You do need to consider that older engines used leaded gas for a reason. They did not have teflon valve guides. That must be compensated for in some way. There are a variety of products to compensate for that issue.

 

Old gas won't run well and gums up the carb parts but what part is "dangerous" for your engine?

Sounds like sensational BS to me.

I've spent many years getting cars going in the Spring following Winter storage. Most owners just stop driving in the Fall and wonder why it won't start in the Spring.

A bit of cleaning and maybe a few parts later (SU fuel pumps especially hate storage) they're running. Often with last years gas (especially if there's already 10-15 gallons of gas in the tank).

Usually no problem.

If the car's been stored for years it's a different story. Usually the gas will be brown and smell terrible. In this case it get drained (and frequently the tank needs repair). You'd never get it running with this brew anyway.

As far as leaded gas goes, it did provide some lubrication to valves/guides but was also important for maintaining valve seat integrity. Later model (since at least the 70's) engines have hardened seats that makes this unnecessary.

Lead substitutes are NOT recommended (GLUE). They can cause more trouble than they're worth.

If you are going to drive your vintage car a lot, just be prepared for new valve seats at the next valve job. After that you're good to go.

Bronze, cast iron, steel, yes but I've never seen Teflon valve guides.

 

Use gas stabilizer when you store it over the winter and you shouldn't have any problems.

 

I agree.

Cars that sit over the winter will usually get water at the bottom of the tank (water is heavier than gasoline) so that's what gets sucked first...vehicle won't start until that gets passed through To avoid this, FILL THE TANK with gas as it leaves no room for condensation to form.

Old VWs use bronze valve guides and stainless steel valves so they don't need lead anymore. I want to say since the mid-60's (?).

 

I believe what they meant is that the lack of lubrication and varnishing effect caused the valve to stick and *could* be dangerous if you have an interference motor. (i.e. pistons will strike a valve if a valve stays open - which is all our motors.)

Those of use who rode motorcycles know the effects of this. If you left gas in the carburetor float bowls, they would varnish over and clog the carburetor jets.

Gasoline *does* go bad, especially race fuel/high-octane fuels. I've had that happen and have had to drain the tank on my Mustang and burn-off that bad fuel in my other cars by mixing it with fresh fuel. It smells bad and burns badly.

If I were storing a car for 3 - 4 months, I don't think I'd worry so much. Adding a fuel stabilizer is a good preventative measure though. If I were storing a car for 6+ months, I would drain the fuel tank completely (as I have done on my Mustang SVO)

Bob

 

Old gas will clog carb jets but it is unlikely to cause a valve to stick open.

I have seen lead substitutes do just that (it is sticky stuff). I'd bet that Jay uses lead substitutes in his old Deusys and that is what caused the stuck valve.

 

What do you guys think of the solution of drilling a small hole in the "bucket tappets," over the exhaust valves, allowing engine oil to drain down in small amounts, over the exhaust valves and springs, and into the guide areas, therefore lubricating the assembly, but not entering the combustion chamber? The engine will smoke with this arrangement, as they stated, but they don't have to meet emission requirements, because of the age of the Duesenburg.

They are doing this because they said that area was dry, and lack of lubrication, was a part in the cause of the valve-sticking failure.

If you looked at the video clip, That straight 8, is a beautiful engine!

Ciao...Paulo

 

The holes might help. A little oil smoke (especially at startup I'll bet).

The Duesenberg is an overhead cam engine, typically exhaust valves get some splash lubrication. Apparently the buckets shield this from happening.

 

Whoa! not so fast with that drill. The Ferrari uses a bucket follower design thats been around since at least the 1940's, its very well proven, and until the advent of pneumatic springs, is the same actual mechanisim at work in F1 cars for several decades. Also, there is plenty of oil pouring all over the valves, springs, and the top of the guide, its just that its stopped from running past the guide like a sieve by the valve guide seal. Some gets by, but ideally just enough to lubricate the valve stem and guide and carry away heat.

Back in the day, it was common for makers like Ferrari to run without a guide seal, and run a close clearance bronze guide and let the oil run through. One of the reasons Valvoline oil was so big years ago, was because it was formulated just for that purpose, to not leak through to fast, and not coke up all over the valve. If you see vintage Ferrari's, Alfas, etc., youll notice a good blast of oil smoke when they start up, but with good guides it generally clears right away. Its from the oil running down the guides after shut down.

I agree with Tim and others, rotten fuel will wreak havok on the fuel system after a good extended period, but it has virtually no effect on the guides. And it really takes more than six months to ruin the fuel in the car sitting in a controlled garage, you really dont start seeing trouble until after about 12 months or so, but after that it starts breaking down rapidly. If you can keep it cool and from wild temp fluctuations, it can last for years. They keep it in underground tanks and it dont go bad. As far as ATF, I have never heard any thing BAD about using it, but I do think its bad for cats IIRC, cant remember. Ditto on MMO, that stuff can be remarkable.

 

Fuel formulations in CT have changed quite a bit over the past few years. MTBF was discontinued due to ground water polution problems and replaced with 10% ethenol, and there are likely other changes too. Mototcycle and landscaping folks are having a tough time keeping their engines running properly after winter storage and most think it is because of the new fuel blends. It seems that the fuels break down a lot quicker today and fuel stabilants don't work as well as they once did, although I have never used them personally. Where I once kept the fuel tanks full when not in use or storage, I now try to run them dry, trading off condensation concerns for fuel break down concerns.

Bill

 

My guess, I am not an expert, is the octane booster alcahol that is used today instead of lead, evperates and over time, basicly the octane rating of the gas fumes away. So if nothing else old premium gas turns into regular or lower.
The varnish that can happen with old gas is worse in my view when it just makes the jets smaller in the carbs, becouse now you have a lean situation that is harder to notice. detanation caused by lean or low octane old gas can be much worse than valve sticking.

 

That's exactly how my engine is designed. Smokes on startup due to the leakeage of oil down the bronze, sealess guides, but this is a feature, not a bug! I only burn a quart every 1500 miles or so.

Some people with really old cars add castor oil to the gas. The Europa community has rejected this for our cars (gums up the works!) but they mention vintage Ferrari owners doing this. Comments?

Ken

 

Went there, did that with my Lusso in latter years. Both you and Paul are right. Short of vast replacement of valve guides, that is the ticket. Octane enhancement is one thing. Valve guide care is quite another.

 

I think you meant teflon valve seals. They are very good at keeping oil off the valve stems, hence not much lubrication as the stems ride up and down in the valve guides. This is where bronze guides come into play.

 

I use Chevron Techron /keeps everything clean, and if it happens to stay parked for any length of time, no worries.
I have also had experience winterizing old marine inboards using ATF with NEVER an issue. Just poured it down the throat (air filters off) a little at a time to begin with, then ramped up the amt. till the motors stalled. They are good and fogged at this point. Come spring time, a couple of shots of starting fluid and they're up and running (a little smokey at first, but it burns off).