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I recommend one additional item.  Add an electric fuel pump in the line on a toggle switch.  Mechanical fuel pumps hate ethanol.  In addition, alcohol boils at a lower temperature than water.  Some old cars take on a new problem with ethanol whereby the vapor lock at high outside temperatures. 

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On 7/1/2018 at 4:12 PM, Philberty2g said:

So, another question, rebuild the original carburetor or go with something else? 

 

Unless a car's original systems were problematic

when they were new, there's no need to change them.

(And those cases are few and far between.  Oldsmobiles

had fine reputations in that era.)

Phil, I recommend keeping and rebuilding the original carburetor.

 

Any changes made that differ from the original

will make you car a bit harder to sell when that time comes,

whether that's 5 years from now or 50.

Lots of changes = Lots of questions = Buyer resistance.

 

I hope you've had a chance to enjoy your car so far this summer!

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On 7/6/2018 at 11:09 AM, Dynaflash8 said:

I recommend one additional item.  Add an electric fuel pump in the line on a toggle switch.  Mechanical fuel pumps hate ethanol.  In addition, alcohol boils at a lower temperature than water.  Some old cars take on a new problem with ethanol whereby the vapor lock at high outside temperatures. 

 

I have a couple of carbureted cars with mechanical fuel pumps and the owners manual for both state that 10% ethanol won't hurt anything and won't void the warranty.  

 

Letting ethanol fuel sit and absorb water is where 95% of the problems come from; water is the problem, not ethanol.  That's why you see more problems in small engines that sit a lot vs cars that are driven regularly.  In Brazil they use 18-25% ethanol in gas. 

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50 minutes ago, theastronaut said:

 

I have a couple of carbureted cars with mechanical fuel pumps and the owners manual for both state that 10% ethanol won't hurt anything and won't void the warranty.  

 

Letting ethanol fuel sit and absorb water is where 95% of the problems come from; water is the problem, not ethanol.  That's why you see more problems in small engines that sit a lot vs cars that are driven regularly.  In Brazil they use 18-25% ethanol in gas. 

 

The ethanol fuels of today are more volatile than the ethanol containing fuels of years ago. Most cars will do OK with modern 10% ethanol fuel as long as you drive it enough to keep the ethanol from sitting. If you let it sit in the fuel system for a long time, problems will tend to occur in the fuel system. I have used ethanol fuels on tours without much problem, but I avoid ethanol fuels when posible. The modern ethanol containing fuels do have a tendency to have vapor lock issues worse than non-ethanol fuels in personal experience with a 1937 Buick 320 engine. The fuel lines are close enough to the exhaust manifold that the fuel lines soak up enough heat for the modern ethanol containing fuels to exhibit vapor lock. An electric  pump can keep the fuel pressurized enough to keep the fuel in its liquid state and flowing when it can otherwise exhibit fuel starvation due to the mechanical fuel pump's inability to pull vapor through the line when the fuel reaches a temperature at which it becomes a vapor rather than a liquid. 

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There have always been cars that were prone to vapor lock, and there are probably more now due to the volatile compounds blended in the gas.

 

It is interesting that no one seemed to be complaining about the gas in the 1980s regarding vapor lock. The cars that always had trouble just still did.

 

I was working in a Texaco gas station in the mid 80s, and at that time I read an oil industry publication that stated that modern fuels were blended with some combination of Methanol, and or Ethanol and or MTBE at close or equal to 10%. The exact brew varied by brand and season. These were used to boost octane in the absence of Tetraethyl lead.  It said you could expect the whole 10% in Super Unleaded, and a little less in Regular Unleaded.

 

MTBE (now banned in some states) and Methanol both boil at lower temperatures than ethanol. We should be having an easier time now.

 

In a case of vapor lock, it pays to look very closely at the check valve function in the fuel pump, and also to make absolutely sure the fuel line has no pinholes, cracks or leaking rubber hoses. Plug the end of the tank pickup and test the whole line with a mityvac. If that doesn't fix it, then look at fuel line location and/or adding an electric pump.

 

The simplest and most reliable fuel supply system ever devised for a carbureted car is a mechanical fuel pump, and a tank pickup with a sock on it. Use it if you can.

 

If it just won't work, using a pull-through pump, on a switch, mounted at the back of the car, as recommended by many on this forum, is IMHO about the best band aid that exists.

 

(Ethanol should still be avoided if possible. It corrodes fuel system parts, and old car enthusiasts would be better off without it.)
 

 

 

Edited by Bloo (see edit history)

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9 hours ago, theastronaut said:

 

I have a couple of carbureted cars with mechanical fuel pumps and the owners manual for both state that 10% ethanol won't hurt anything and won't void the warranty.  

 

Letting ethanol fuel sit and absorb water is where 95% of the problems come from; water is the problem, not ethanol.  That's why you see more problems in small engines that sit a lot vs cars that are driven regularly.  In Brazil they use 18-25% ethanol in gas. 

I totally disagree.  It depends on the age and type of the car.  I had a 1971 Buick that never had a problem with ethanol except that it would, yes, get water in the fuel and occasionally skip a beat from it.  However, my straight 8 Buicks will not run on it.  The fuel line runs between the thermostat housing and the cylinder head.  In fact, there is a metal bracket bolted to the head that holds the metal fuel line in place.  The cars can be driving okay and you stop for gas.  They will start right up and run about 100 feet or less and run out of gas because they are vapor locked at the thermostat housing area.  This happens on Florida hot days  Or, on a 90 degree day you can be driving down the road a 50 mph and all of the sudden simply run out of gas.  Water passes through the engine restarts itself, air doesn't.    Any fool knows alcohol boils at a lower temperature than water (except the government engineers, who don't care).  I've wrapped the lines in insulation and I think that has helped, but not cured problem.  The '39s do not ever experience the problem on real gas.  I've had the one since 1963 and it never ever once did this or had this problem on real gas.  Condensation from sitting is also a problem with ethanol, but not the main problelm, which is heat.

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I always seem to have a conflict of thoughts when I hear the mechanical/juice brake, disk/drum arguments and reasonings. I grew up right in the transition time of drum to disk. The reasoning given was for brake fade, not stopping power. I have drum brake vehicles, disc/drum vehicles, and all disc vehicles. First, on mechanical brakes, I’m still waiting to replace my first blown brake line(yes, sarcasm) and I can stop my 31’ Chevy with its drum brakes virtually on a dime, well, a slightly long dime but still very quickly. My restored 83’ diesel blazer, drum rear, disk front ( transition vehicle and front only as the front has more work load and prone to fade more than the rear in traffic when carrying a load) will literally throw you through the windshield with just a little extra push of the pedal, locking up all four wheels easily and they are oversized BF Goodrich AT radials. My personal all disc vehicles are my 08’ GMC diesel cc dually and my 14’ accord. My accord stops very well and it’s my work vehicle seeing many high speed miles here in New England where tons of traffic, poor drivers, and emergency stops are a everyday occurrence. My 08’ GMC is by far my worst stopping vehicle! It has huge rotors and calipers on it yet it will coast through some stops when loaded that if it wasn’t for my class A driving experience, would have resulted in a few accidents. So GM got rid of the old rear drum, front disc, great stopping setup for this new and improved, brake critic recommended, all disc system that stops like crap! Why does it stop like crap? For the same reason most brake fading occurs........  People just can’t drive so now GM adds “antilock” into the mix because people constantly use their brakes more than they should and all of a sudden a new reliability problem arises, warped rotors. Now people can’t understand this new problem they never had riding the brake pedal in their drum brake equipped car. So the manufacturers have to help us drive, so along comes antilock that takes all the braking “feel” out of the pedal and proceeds to make all the new drivers incapable of driving anything that isn’t completely computer assisted. Out driving on the highway with a 40’s up car just requires real driving and diligence that people used to have before the computer age. As a class A driver with my endorsements, this is the ONLY way I drive, no matter if it’s my Accord or my 31’ Chevy. I seriously doubt anybody with a well adjusted brake system in our older cars would ever experience brake fade under normal driving conditions. Now an older Ferrari or Lamborghini designed to go fast and driven hard around corners warrants that big disc system that was installed on it. They are prone to brake fade, an old Oldsmobile, not so much.

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Forgot to mention, put new belts on the car and keep new spares under the seat. It’s getting hard to even find the correct size V belt these days. Pull the radiator and have it flushed, change out the thermostat along with all the hoses as earlier recommended. Don’t forget the heater hoses. I’ve seen a blown one ruin many a cruise day for lots of people. They get old and hard with age and sometimes just disintegrate at the wrong time. Absolutely make sure all gauges work as too many drive around assuming they have fuel, oil pressure, or are running cool. 

    Then after you do all this realize that any of the new components you’ve installed can fail at anytime. Of course not just on your old car but you modern car too. It’s the way it goes. I recently installed a new fuel tank on my 83’ Blazer because the tank seam leaked and purposely installed a new sending unit though the old original was working fine. My logic was I’m in here, might as well go with all new. Sure enough, two months later that new fuel sender just quit! Stuff like this is what really aggravates me!

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I drive my own car (a 65 Barracuda) as much as I can while the weather is good - no snow) and 4000-5000 miles per year isn't unusual.

 

If you have more than one car, I would keep your 1955 Oldsmobile as a FAIR WEATHER daily driver.  As others have stated, the more you drive it, the more reliable it will become as old failure-prone parts are replaced.  There is no need to expose your car to the hazards of adverse weather conditions.

 

Presumably, your engine is mostly stock with the original carburetor.  If you're having carburetor problems, you're better off rebuilding your own carburetor than getting a remanufactured one from the parts store.  There is no guarantee that the reman was done right or that the carb is properly calibrated for your car.  If you can find vintage speed parts for it, then this might be a good opportunity to switch to a different carburetor.

 

If you have a cold hesitation, it would be good to check the condition of the manifold heat control system (heat riser) and you might need to free or lubricate the valve. If you a have vee-engine, the cross-over passage might be plugged with carbon.  I would also check the operation of the choke mechanism.  I do not recommend disabling this system even in hot climates.

 

Vapor lock can be problem for carburetor cars and an electric fuel pump can often help.  See Vapor Lock for more information.

 

Neglected engines can also have a large amount of rust & scale inside the block. I would do an acid flush (citric or oxalic) and refill with a 50/50 solution of antifreeze.  See Cooling System.

 

If you're still using a non-detergent engine oil, switch to a Heavy Duty Engine Oil.  See the Corvair Oil Guide and Engine Wear.

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On 7/1/2018 at 5:00 PM, D Yaros said:

I will join the chorus of "Yes, it can/should be driven" regularly.  As stated, it was intended to be a daily driver when produced and there is no reason it cannot be such today; provided you can afford the gas!

 

 

I would say it gets better MPG than my Tahoe. 😂 

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