The Mustang Chronicles: Carburetion

 For decades, carburetors were the primary devices for mixing fuel and air at a ratio to maximize combustion in gasoline powered engines.  These devices are simple in theory - they used the flow of air to regulate the metering of fuel, creating an ignitable vapor to generate power.  Over time, they became more complex to provide increased power and meet ever increasing emissions regulations.  With those changes, they gained a reputation of being clunky, inefficient, and unreliable.  This reputation is undeserved in most cases.  Carburetors have been used on everything from lawnmowers to large aircraft and are still used for many applications today. 

(Carter YFA one barrel carburetor)

The 1965 to 1967 six cylinder Mustangs originally came with the Autolite 1100 carburetor, as did most Fords with the Thriftpower six.  The Autolite 1100 is a one barrel carburetor developed by Ford as a replacement for the Holley 1904 and 1940.  It included an automatic, hot air choke and a spark control valve to manage ignition timing.  A common upgrade for these engines is to swap out the one barrel carburetors with two barrel units, and replace the Load-O-Matic distributor with a Duraspark or DUI/HEI.  This conversion can be done using an adapter for the Thriftpower's Log Head intake manifold, or by modifying the intake to accept a two barrel carburetor.  

Switching to a two barrel carburetor provides more horsepower by increasing the volume of fuel/air, which is measured in cubic feet per minute (CFM).  Increased CFM volume equates to more power through larger displacement, either due to the size of the engine, or by increasing the engine's speed, measured in revolutions per minute (RPM).  

But there is more to the math than just increasing CFM volume.  You also have to consider volumetric efficiency (VE), which is defined as the ratio of the mass density of the air-fuel mixture drawn into the cylinder at atmospheric pressure, to the mass density of the same volume of air in the intake manifold.  Or in plain English, you can't shove more gas into an engine than it can expel as exhaust.  That's why bolting a Holley 750 Double Pumper on the Thriftpower six is the automotive equivalent of the Milk Gallon Challenge.  

I'm more worried about drivability than power.  I want better street performance from a torquey engine with good throttle response.  The engine is basically stock, with the original camshaft, pistons, crankshaft, and exhaust, so I'm not going to get much benefit from a two barrel carburetor conversion.  

A better choice is to replace the Autolite 1100 with another one barrel carburetor and upgrade to the Duraspark or DUI/HEI distributor.  Ironically, many people swap out the Autolite 1100 for a Holley 1904, 1940 or "universal" one barrel carburetor.  Or, you can go with a Carter YF or YFA, like I did.  

I went with the Carter YFA for reliability and compatibility with my stock setup.  The YFA was used on a variety of Ford cars and trucks from the 1970s into the 1980s and bolts on with no modifications to the fuel line or throttle linkage.  It also provides the improvements in performance I'm looking for.  At some point in the future, I'll probably do a complete tear down on my engine, upgrade the camshaft, exhaust, and go to a two barrel carburetor.  But for now, I'm more interested in driving my Mustang than rebuilding it.          

A Time to Sell

I'm selling my daily driver...

In the past year I've driven my Ford Fusion about 3,000 miles.  Since the start of the pandemic, it's been driven less than 5,000 miles - More than half of those miles were put on by my daughter, before she got her own car.  Now I've reached the conclusion it's time to sell.  

I still like the Fusion, which I bought new in 2013.  Over 78k miles, it's been almost flawless as a daily driver, requiring regular maintenance and one minor repair to replace a fuel pressure sensor.  It's averaged about 26 MPG - lower than the EPA combined estimated, but not far off the mark.  Manufactures have been gaming the EPA test for years with smaller displacement turbo charged engines, and Ford is no different.  The 1.6 turbo 4 cylinder makes 188 horsepower and about an equal amount of torque.  It's a good engine, but buzzy and lazy when paired with the 6 speed automatic.  

My other complaints are minor.  The electric steering is numb, lacking any road feel, and it's light, like using a Logitech racing wheel.  I also don't like the 18 inch wheels with low profile, 45 series tires - they aren't well suited for pothole and metal plate strewn Midwestern roads.  

Complaints aside, it's the best car I've ever owned for transportation.  It has the best ride - a good mix of comfort for long stretches of interstate highways coupled with enough backroad competence to justify taking the Blue Highways.  And the way the car looks...

Ford obviously cribbed off Aston Martin before they sold it off, and they got away with it.  It's hard to overstate the reaction people had to the second gen Fusion.  It caused a stir like the girl in the red dress in the "distracted boyfriend" meme.  It still looks good today, to my eyes, much better than the bland restyling in 2017. 

I never regretted buying the car, and if I still needed a daily driver, something to commute 30+ miles a day, I'd keep it.  But my commute is now a short walk from my bedroom to my desk.  My occasional Starbuck's detour has become a trip to the coffee maker.  And the Fusion spends its days parked under a tree, sprinkled with tree sap and bird shit.  A layer of dirt formed under the rear spoiler, and the other day I found acorns in the air box, left by mice or even a squirrel.  I just finished the engine work on my Mustang, and with access to several other cars, the music has stopped and the Fusion is without a chair.      

One of the many weird things to come out of the pandemic is the sudden jump in used car prices.  A global computer chip shortage and supply chain issues have left auto manufacturers with a shortage of new cars, at a time when demand for cars has spiked.  I've gotten countless emails and junk mail from dealers offering top dollar for my car.  This week I made the mistake of looking up the value and was shocked at how high it was.  Yesterday I dropped by the dealer, and the used car manager offered more than the book value.  

Tonight I'm going back to the dealer with my payoff note and the extra set of keys.  I expect to walk out with a nice check and fond memories.  

Dad's Rules for Driving

 I have two teenagers who are driving.  My son is 19 and goes pretty much anywhere he wants.  My daughter is not quite 16, but has her restricted license and drives herself to school.   

I came up with four rules to follow.  I wanted the rules to be simple, easy to remember, and applicable to most situations:    

1. Drive like I'm in the car.  

2. Be aware of everything around you.  Don't assume the other car/pedestrian/cyclist sees you or is paying attention.  

3. No passengers.    

4. If you ever feel unsafe to drive, for whatever the reason, call me and I'll come pick you up. 

Log Head Arithmetic

 The Ford 144/170/200 inline 6 is a simple, durable engine that is easy to work on.  It is a "cam in block" design, meaning the camshaft is inside the engine block, and the valves are actuated by pushrods.  From 1960 until 1983, it was the workhorse used in the majority of Ford's small and intermediate cars.  

The one shortcoming of the engine is the cylinder head - the intake manifold and cylinder head were cast as one piece for simplicity and to save on production costs.  Known as the Log Head, because the intake manifold looks like a small log with branches feeding the cylinders, it is a restrictive design and provides an uneven flow of the fuel/air mixture.  Early engines, made from 1960 to 1967, had the small log head.  Beginning in 1968, Ford changed the design of the cylinder head and increased the intake volume, which provided slightly better performance.  These engines were produced up until 1983, in cars like the Maverick/Comet, Granada/Monarch, Fairmont/Futura, and Mustang, and are referred to as large log heads.        

(The small log head from my 1965 Ford Mustang - the log is behind the valvetrain with pushrods)

The best way to increase performance on a pre-1968 six cylinder is to swap out the small log head for a large one.  From there, you can add a dual outlet exhaust header, Duraspark or DUI/HEI distributor, and a bigger carburetor.  You can also buy a 2 barrel carburetor adaptor or modify the intake manifold to accept a larger carburetor.  

(Large log head on the same engine - this head was cast in 1973)

Swapping out the cylinder head is straightforward, but not something to take on if you're a novice mechanic.  The Ford Six Performance Handbook provides detailed instructions on the steps involved, expert tips, and things to watch out for.  In addition to the advice in the book, here are some additional things to I learned:  

• Cylinder heads are all interchangeable for all years and displacements, but you will want to factor in combustion chamber sizes and compression ratios so you don't end up with too much or too little compression.    
• The cylinder head itself weighs about 65 pounds.  You will need help lifting the old one and installing the new one.  
• Ford changed the sensor for the temperature gauge in late 1965, so you will need a new temperature gauge if your original cylinder head dates before August of that year.  
• The carburetor spacer for the small log does not fit the large log - the bolt holes are about 1/2 inch further apart.  Additionally, the bore for the intake is about a 1/4 inch larger in diameter. This difference, in addition to the wrong carburetor gasket, will cause vacuum issues, leading to stumbling and hesitation.  
• If you go with a different carburetor, you may have to modify the linkage for the accelerator pedal.  The only carburetors I know that don't require this modification are the Carter YFA, Holley 1904/1940 and the Daytona or Universal carburetor. This modification is not difficult but you will need to purchase the V8 accelerator pedal and linkage.
• If you use a Duraspark or DUI/HEI distributor, you will need a larger gap for your spark plugs - from 32-35 to .45 or more.    

Done right, these modifications can increase power by 30% while costing less than $1,200.  The result is usable, every day performance that approaches the base V8 models of that era, making the car more lively and enjoyable while still maintaining a vintage feel.    

The Original Maverick was a "Hand-me-down"

 I hated the original Maverick... but was wrong to do so.  

Growing up in the 80's, the Maverick was a hand-me-down car.  It was as fashionable as a pair of hand-me-down Toughskin bell-bottoms from your older brother.  Cool cars of that era included coupes from the 60's, 80's Japanese imports, Firebirds, or two-door Cutlass Supremes.  Mavericks were the tragically unhip, back of the lot specials, and the kids that drove them would hide out until everyone else left school.  

The Ford Maverick replaced the Falcon in 1970.  It had the Falcon's hand-me-down platform, which dated back to 1960.  Engine choices were also handed down from the Falcon, including the 170/200/250 Thriftpower 6 and the 302 Windsor V8.  But the Maverick sold well and compared favorably to its contemporaries in the compact/import category.  It also wasn't a bad looking car either.  Early examples of the coupe had clean lines with classic long hood/short deck proportions.  I think the car even looks a little bit like a Ferrari 250 Lusso, which may have been intentional on Henry Ford IIs part, since he looked for every opportunity to stick it to il Commendatore. 

Viewed without malice or my 80's teenage New Wave and synth pop/post-modern cynicism, I've realized the original Maverick was a good car for its time.  A cheap, practical appliance that met the 1973 Oil Crisis, and ever changing pollution and safety regulations.  This year Ford is launching a new Maverick, and while the new one is a truck that offers a hybrid drivetrain, it is also a car for it's time.      

Regardless of what form vehicles take in the future, whether they are cars, trucks, or crossovers powered by hydrocarbons, hydrogen, electricity, or nuclear fusion, we will still need cheap cars.  Vehicles that are reliable, practical appliances, ones that eventually become hand-me-downs, even tragically unhip ones, sitting in the back of high school parking lots.

$15,000 Question: The Corvette C3

Built between 1968 and 1982, the third generation of America's sports car suffers from a reputation of being a plaything for middle-aged guys who dress in Hawaiian shirts and have hair like Ern McCracken.  It is the most bombastic of all the Corvettes.  Where the 1963 to 1967 Sting Ray conjures up images of the early Space Age, and the 1984 to 1996 C4 packed some legitimate performance cred, the C3 comes off like a lo-fi disco parody.   Google "Corvette Summer" if you're not sure what I mean.  That movie makes the Smokey and the Bandit sequels look like The Godfather in comparison.

The C3 Corvette was built on top of a modified C2 chassis.  Starting in 1971, it was steadily gelded until it reached its nadir in 1980 with a 305 cubic inch V8 and an 85 MPH speedometer.  At 182 inches in length, and weighing a hefty 3,500 lbs, it cuts the same swath as a midsize car.

Still, there's something about the C3.  It looks good, all curvy and low slung in a way that stood out against the Brutalist styling of that era.  It was also more comfortable, more practical, and better performing than the Ferrari 308 or Lotus Esprit.  Even as late as 1979, the L-82 Corvette's 0-60 times were in the mid 6-second range.  The small block Chevy 350 offered bullet proof reliability and plenty of torque.  It's also easy to find parts, and there are no shortage of performance upgrades.

I've driven several C3s and can attest to all of the vices.  They are crude and ride like every chassis bolt needs to be tightened a full turn.  The car was victimized by cost cutting and primitive emissions controls.  It is very much a car of the Malaise era, Prog-Rock on four wheels.  

However, like Prog-Rock, there is a lot of good things about the C3.  You sit low in the bucket seats, peering down the valley of the hood, between the sharply creased fenders.  The dashboard slants away from you with two large gauges for the tach and speedometer in front of you, and five smaller gauges in the center console.  The exhaust burbles somewhere behind you, a throaty sound that modern cars can't imitate.  If you're lucky enough to row your own gears, the four speed manual is smooth and positive and the engine provides enough torque to lope around town in third or fourth gear without lugging. 

If you're looking for the sprite-ness of a British sports car, or the precision of a Porsche Boxster, you'll be disappointed.  It's more of a grand-tourer than Gran Turismo Omologato, a car you can use to commute or travel long distances.  If the C2 competed with the Jaguar E-Type, the C3 is a Chevrolet XJ-S, only more rough around the edges and better to drive.