64 Tbird gas

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If it has the 390 fe or the 427 fe either engine needs premium as the engine is at least 10.5: to 1 these motors also were designed to run on leaded gasoline which if the heads haven't got harden exhaust seats installed. ..you should use a lead substitute if you plan on taking it out for some lengthy long drives. So in a nutshell at least 91 octane with a lead substitute added to each tank of gas, unless you know that the cyclinder heads have the upgrade.
 
I think the book will tell you 100 octane, but that's by an old standard. The 91 octane would be fine.

As for lead, I think that's a bit overrated. Remember, Amoco had, and heavily advertised, unleaded gasoline back in the 1960's and people used it without hesitation. Basically if you plan on hard driving through mountains, or pull trailers frequently, you might want to find some lead to put in there. Easy casual driving, such as to and from car shows, makes no difference. Then, if the motor gets rebuilt, it will most likely get hardened valve seats -- end of problem.

You might also consider replacing any rubber hoses in the fuel line. They're old anyway, but the old-style rubber can break down slowly with the newer formulated gas-ethanol.

In my case, I've got a rebuilt motor with a blow-by problem and compression is low. Someday I plan to have it rebuilt properly, but for now I'm using mid-grade gas with no problems whatsoever. On occasion I've accidentally put in regular, and it runs fine -- but if I nail it I get a small amount of knock. The knock is a sign of burning too quickly, and octane needs to be raised to prevent it.
 
I just bought a 64 T-bird during labor day week in 2017. My 390 was rebuilt but I still use high grade. Please keep me in touch how your 64 is doing. I am still new to the Thunderbird world, coming from (cough) Mustangs. I am learning while I go and any advice would be greatly appreciated .
 
Well, high grade is what you SHOULD use.

A lot of people have trouble understanding what high grade gas actually is. After all, we remember TV commercials that make you think that THEIR high-test gas gives you more horsepower, or better mileage, or something. Gas is gas, it's the motor that gives you good or weak performance. But one major way to increase power is to increase the motor's compression. The tradeoff is the tendency to "pre-ignite". When the air/gas mixture is heavily compressed, it gets really hot, and it ignites before the spark plug fires. That's what sounds like marbles inside the motor. A higher-compression engine requires a higher-octane gas, as the octane is a retardant that reduces the tendency to pre-ignite.

In the case of my motor, which is a LONG story, the compression actually measures low. My guess is incorrect rings. Whatever, it burns oil like crazy. I've figured as long as the compression is low, I'll take advantage by using mid-grade gas -- and it runs fine. Oh, someday I'll have a local shop go through this motor for me.

Nothing wrong with Mustangs -- they are neat cars! On the good side, they are easy to work on, parts are readily available and cheap, the cars are simple and practical, and they make great daily drivers. On the bad side, as old cars go they're a bit too common -- take it to a car show and park it with all the others. Thunderbird is more of a luxury car, built in the Lincoln factory with the attitude of "why use 3 moving parts when you can use 47?", and with a smaller population base you'll find some repro parts are up there in price. For whatever strange reason the finished car isn't worth that much -- can't figure that one out. I guess it's not a sporty muscle car, it has all the hardware but weighs twice as much. But it's certainly a nice ride, and it is definitely an attention-getter!
 
I have a 65 with 390 typical, and use non-ethanol gas when convenient, seems to make a difference in pinging. As well, it was suggested, and I complied, to put a lead additive in the oil.
 
The old substitute for lead in the gas is Marvel Mystery Oil. It help lubricant the valves and keep the Valve Seals lubricants. It can’t hurt. Put one can in for every tank full.
 
Thanks to all of your for the suggestions. I ended up finding a great lead substitute. With that and Premium gas, it cleared up all problems including the smoking from the tail pipe.
 
You might also change out the points to Pertronics Electronic Ignition and a Flamethrower Coil. It ups the voltage at the spark plugs from 30,000 volts to 45,000 volts which makes the engine run cleaner. It only cost about $100.00. Good Luck. Rick.
 
I have a 65 with 390. The engine has been rebuilt a few years ago. I use Exxon Premium and a can of lead substitute.
The only problem I have is when I first start off I get a hesitation up to 25-30mph then its ok. Any suggestions
Thanks Dennis
 
Check the vacuum advance in the distributor it might be sticking and need to be cleaned.
 
Is there a hose going from the vacuum advance to a vacuum port on the carburetor ??? If you open up the distributor and remove the plate that the points sit on there should only be 2 screws. The advance is under the plate. Put some WD40 to free it up and then then put some luberplate grease on it. Because you don’t use the car every day you might want to do it every spring. They do get stuck because of lack of use. Take a picture of it before you take it apart. Don’t remove the points from the plate just take the whole plate out this way you won’t have to set the dwell again. Good Luck Rick.
 
It sounds harder then it actually is it shouldn't take you more then 30 minutes to do the whole job. Good Luck Rick
 
No leave everything hooked up and just remove the plate and you will see the weights there. Just make sure they move freely. Also make sure the vacuum advance is working. Move the arm of the advance all the way out and put your finger over the nipple for the hose then see if it returns back to the original position with your finger on it. If it does you might have a bad vacuum pot. Another way to test it is to have a timing light on the motor and see if the timing mark moves on the damper wheel as you bring the throttle up. Some of the vacuum advances are adjustable find an Alan wrench to fit in the nipple where the hose fits on. When you tighten it that brings in the advance sooner and if you loosen it it brings in the advance later. I hope you cure your problem Rick
 
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