What is the best gas to use in my 383? Should I upgrade the cooling?

[67fish383S]

Sorry if this is a stupid question or has been covered in other threads, but I'm looking for opinions on the best type of gas to use in my new-to-me '67 Barracuda Fastback. It was originally a 383 and still is, but the block is a 1970 casting with correct engine mounts. It has a Carter AVS four barrel and the original 4 speed and 3.23:1 sure grip diff. Electronic ignition.

The person I bought it from just recommended premium gas, but then someone else suggested Ethanol free. Thoughts?

Also wondering about cooling. It idled a little hot on the first drive home and when I checked the coolant level later, it needed about 1/2 gallon to bring it up to the filler neck. No signs of leakage or spray that I could see. All the hoses look good and the coolant is normal color. The radiator is the original PN # 2785929 for the 383 engine. Not sure about the water pump, but assume original. Also I have not been able to nail down whether or not the engine has been rebuilt (still working on collecting history, which is sparse at the moment). It has run cooler overall since I filled it, but the weather is cooler also.

I hate to mess with originality, but also want it to be a stable driver. Should I consider a radiator, fan and/or water pump upgrade? I imagine electric fans are considered a capital offense. ;) But it tends to get stupid hot/humid around here this time of year.

 

[rustycowll69]

in the PNW, ethanol free gas is about double the cost of regular 10% ethanol gas. If you can afford it, and can find it locally, have at it.

 

[yellow rose]

Beautiful car. Very cool.

I’d be more concerned with keeping 91 octane in it rather than worried about the minimal amount of ethanol in the fuel.

As long as you can keep the temp under 200 degrees or so on your hottest days I’d leave the cooling system alone.

As long as someone hasn’t messed with the OE cooling system it’s pretty hard to beat. Chrysler had it together on its cooling system.

 

[yellow rose]

in the PNW, ethanol free gas is about double the cost of regular 10% ethanol gas. If you can afford it, and can find it locally, have at it.

Yep. I’ve seen it as high a 4.99 a gallon on the west side and as high as 3.79 on the east side. You can find it cheaper. You just have to look.

 

[Joey4speed]

Nice car.
I also have little history and wanted originality.
I run any high octane fuel here in the east and so far so good.

My 69 383 also ran too hot in traffic, but a timing adjustment, and richened up the carb a bit (by a good old school mechanic) helped.
I installed the period correct clutch fan after some advice, it wasn't "original" with my car but its not obvious.
They all helped the overheating issue.
It may be a little late to do do this season, maybe get the original radiator re-cored at GlenRay.
Give them a call for estimates and turn around time. They can replace the core for extra cooling and keep the look if your radiator tank is original or has period correct numbers.

 

[Demonracer]

Acquiring the history as you are trying to do is a good thing, If all else fails, get a bore scope camera & look into the cylinders to see what the pistons look like. Check to see what thermostat is in it, as well as what water pump is on it. (Standard, or high flow). Take the car on short cruises around your neighborhood at posted speeds & observe the temperature, as well as short highway cruises.

 

[lilfontleroy]

Sorry if this is a stupid question or has been covered in other threads, but I'm looking for opinions on the best type of gas to use in my new-to-me '67 Barracuda Fastback. It was originally a 383 and still is, but the block is a 1970 casting with correct engine mounts. It has a Carter AVS four barrel and the original 4 speed and 3.23:1 sure grip diff. Electronic ignition.

The person I bought it from just recommended premium gas, but then someone else suggested Ethanol free. Thoughts?

Also wondering about cooling. It idled a little hot on the first drive home and when I checked the coolant level later, it needed about 1/2 gallon to bring it up to the filler neck. No signs of leakage or spray that I could see. All the hoses look good and the coolant is normal color. The radiator is the original PN # 2785929 for the 383 engine. Not sure about the water pump, but assume original. Also I have not been able to nail down whether or not the engine has been rebuilt (still working on collecting history, which is sparse at the moment). It has run cooler overall since I filled it, but the weather is cooler also.

I hate to mess with originality, but also want it to be a stable driver. Should I consider a radiator, fan and/or water pump upgrade? I imagine electric fans are considered a capital offense. ;) But it tends to get stupid hot/humid around here this time of year.
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There are no stupid questions, but plenty of stupid answers to be had! Everything YR said is spot on. Go with good gas, I like aviation fuel occasionally. Past that, if it ain't broke....
The low radiator fluid level is a little concerning, is there any "milking" of your oil? Best place to check is under the oil filler cap. If yes, you may have a cracked head or..?? With the car running check for liquid out of the exhaust. If none of this applies, just RUN IT! And unless you're showing the car and going for trophies, don't sweat the electric fan thing, if you think it needs it, do it.

 

[Joey4speed]

Im old enouugh to remember in the 60s, all the overheated cars on the side of the roads in the summer traffic.
It was a common occurence.
Glad we can circumvent that with todays technology.

 

[toolmanmike]

Use the highest octane you can find without ethanol. If it pings you might need to back the timing off or fix your timing curve in the distributor.
If you're not blowing coolant out you're not overheating. The system can and will get over 200° and not be an issue.

That's a beauty of a Barracuda.

 

[67fish383S]

There are no stupid questions, but plenty of stupid answers to be had! Everything YR said is spot on. Go with good gas, I like aviation fuel occasionally. Past that, if it ain't broke....
The low radiator fluid level is a little concerning, is there any "milking" of your oil? Best place to check is under the oil filler cap. If yes, you may have a cracked head or..?? With the car running check for liquid out of the exhaust. If none of this applies, just RUN IT! And unless you're showing the car and going for trophies, don't sweat the electric fan thing, if you think it needs it, do it.

Did not see any evidence of coolant in the oil on the dipstick, but I'll check the filler cap. No juice at the tailpipes either that I've seen and it runs really well. The low coolant level was surprising, especially considering who I bought it from (Norm VerHage, the tech guy from the Barracuda Owners Club, who has a killer collection of original fish that I saw with my own eyes), but as of yet I'm not too concerned. I'll keep an eye on it and baby her until I have a better feel. Thanks!

 

[Demonracer]

The low coolant may have been evaporation from non use by the PO. He probably kept it up, but may have overlooked the coolant level. I know that my when bracket cars sits over the winter that I lose a little of the water & water wetter in the radiator due to evaporation.

 

[diymirage]

spring lake...thats over the 'zoo right?

cool

its kinda hard to decide what "hot" is
i take it you only have the stock gauge that goes from C to H

hard to tell on that if you're running at 180 or 220

one of those infrared thermometers will tell you though

does it have a radiator shroud?
if not, get one

simple to install, looks OEM and can be removed when you want to

also, you're running a 50 year old waterpump?
that may no longer be working as good as it once did

 

[toolmanmike]

By the way, I don't know what the manual says but neither of my cars like the coolant to the filler neck. You need some room for it to expand. Those cars didn't have a sealed system with a overflow tank so if you overfill it, it will blow some out the overflow.

 

[67fish383S]

spring lake...thats over the 'zoo right?

cool

its kinda hard to decide what "hot" is
i take it you only have the stock gauge that goes from C to H

hard to tell on that if you're running at 180 or 220

one of those infrared thermometers will tell you though

does it have a radiator shroud?
if not, get one

simple to install, looks OEM and can be removed when you want to

also, you're running a 50 year old waterpump?
that may no longer be working as good as it once did

Spring Lake is near Grand Haven on the West shore. Agree on the C/H thing, but it was obviously too far on the H side before I checked/filled the coolant. Thanks for the tip on the shroud. I'll check it out. I doubt the WP is the original, but it could be. I was more thinking stock vs. high flow. Thanks

 

[67fish383S]

By the way, I don't know what the manual says but neither of my cars like the coolant to the filler neck. You need some room for it to expand. Those cars didn't have a sealed system with a overflow tank so if you overfill it, it will blow some out the overflow.

I actually thought about that before I filled it, but wanted to be on the safe side. I figured worst-case it will find the level it wants to be at and blow out the excess if I was wrong to fill it. Haven't had a chance to re-check, but will do that today. Thanks!

 

[Dana67Dart]

IMHO...
use the grade of fuel that doesn't ping. It might be a lower compression eng and run fine on regular. It might need mid grade or premium.

That being said.... It won't hurt to run premium and if you only put 2000 miles a year the extra cost is about $100.00 per year.

As to cooling... Manage by fact, get a real temp guage and find out where you are, using an infrared at the base of the temp sender would probably wood good. Or perhaps the temp of the upper rad hose

 

[yellow rose]

IMHO...
use the grade of fuel that doesn't ping. It might be a lower compression eng and run fine on regular. It might need mid grade or premium.

That being said.... It won't hurt to run premium and if you only put 2000 miles a year the extra cost is about $100.00 per year.

As to cooling... Manage by fact, get a real temp guage and find out where you are, using an infrared at the base of the temp sender would probably wood good. Or perhaps the temp of the upper rad hose

You only need as much octane as you need to control detonation. After that, it’s just spending money. But, the lower grade fuels are full of fillers and junk. They burn considerably dirtier than premium does.

Just an FYI.

 

[Dartnut]

Nice car, there are a lot of great tips given by the people here.
One thing I would do is have the cooling system flushed and pressure tested.
And resist the urge to put in straight water into the cooling system.
The mixture I use is 50/50 distilled water and anti freeze (coolant).
It is not just for keeping the system from freezing in 40 below weather, it also lubricates the system and controls the heat better.
Water wetter is supposedly good too, but have never tried it.
Anti freeze or water wetter is a must have with distilled water if the cooling system has any aluminum components in it such as heads, water pump, or radiator.
Buy a good quality thermostat for the car, it's well worth the money, same as a new high volume water pump and a new radiator cap.
Change the hoses if they are old.
Why leave anything to chance?
Some people make the mistake to remove the thermostat completely, and it only makes the problems you have with overheating worse.
Shrouds and clutch fans are a great idea as well.
Lastly, make sure you have the factory rubber seal on the hood that seals the hood to the rad support.
Good luck, and let us know how it goes........