1 This is the 144ci Falcon...
1 This is the 144ci Falcon six as it appeared in 1960. Externally, it looks the same as the later Mustang's 170 and 200ci four main bearing sixes. That first year, the 144 had a glass bowl Holley one-barrel carburetor and was a gutless wonder with less than 100 horsepower.
Ford's lightweight six-cylinder engine debuted in the '60 Falcon and Mercury Comet as the 144ci six. It's strong on reliability but not much on power. A year later, Ford upsized the 144 to 170 ci with an increase in stroke, which improved power but didn't rock the planet. When the Mustang was introduced in April 1964, it got the Falcon's improved seven main bearing 170ci six as standard equipment. Producing 105 horsepower at 4,400 rpm, this engine's message was never about power but more about economy for buyers who needed a fuel stingy, reliable powerplant.
Detroit has come a long way over the past nearly 50 years, so it's easy to get spoiled by technology and comfort. Improvements like electronic fuel injection, roller camshafts, overdrive transmissions, and four-wheel disc brakes have made automobiles more fun to drive. Driving an old six-cylinder Mustang is more about the spirit of driving a classic than it is about comfort. These cars put you more in touch with the road than today's technological wonders. And face it, there's only so much you're going to be able to do with the classic inline sixes, including the later 200ci version. However, you can make the most of these engines if you know what to do.
2 Here's the Mustang's 200ci...
2 Here's the Mustang's 200ci six as it appeared in 1966. Ford took the basic 144/170 design and redesigned the block with seven main bearings instead of four for improved strength and reduced noise, vibration, and harshness. This redesign made Ford's little inline six fiercely reliable and certainly capable of great power gains.
The largest culprit with vintage Ford sixes is fuel distribution. Their integral log-style intake manifold, which was conceived to control manufacturing costs, makes these sixes frustrating to live with. They suffer from rough idle quality no matter how many different carburetors you try. They stumble off idle and surge or hesitate while cruising. We tend to blame these performance issues on the carburetor, but that isn't always the case. Poor fuel/air distribution along the integral intake manifold and into the cylinder head creates all kinds of performance issues. It can be the luck of the draw because no two castings are alike. Some sixes run like a clock while others can't get out of their own way.
Turbulence along the log manifold tends to upset fuel droplets in suspension, which enter intake ports erratically. End cylinders tend to run lean while inboards run rich. To add insult to injury, Ford placed the one-barrel carburetor above a hot exhaust manifold, which causes all kinds of heat-induced problems (percolation and vapor lock) in hot weather.
3 This is the Autolite 1100...
3 This is the Autolite 1100 series carburetor used on the 170 and 200ci sixes from '63-'69. Shown is a '65 version with spark control valve for use with the Autolite Load-O-Matic distributor, which doesn't have mechanical advance. The spark control valve meters vacuum to the distributor's vacuum advance as rpm increases. Spark control does not exist on '66-'67 California emissions or '68-'69 49-state.
The Autolite 1100 one-barrel carburetor installed on classic six-cylinder Mustangs suffers from engineering shortcomings, with rough idle and hesitation among the biggest complaints. Jon Enyeart of Pony Carburetors tells us that these shortcomings can be engineered out with a professional rebuild and restoration. When Pony Carburetors rebuilds the 1100, it rolls in improvements that eliminate hesitation, stalling, and rough idle. However, despite Jon's best efforts, some drivability problems cannot be eliminated because fuel distribution problems transcend the carburetor. You can have the best carburetor in the world, but if air and fuel have trouble getting to the intake ports, drivability will continue to suffer.
The Autolite 1100 one-barrel carburetor was introduced in 1963 and was used on the 144, 170, and 200ci engines through 1969. Because six-cylinders are low-buck powerplants by design, Ford had to figure out the most cost effective way to produce them, hence the log manifold design. It also had to simplify carburetor design for reasons of economics. There were three basic 1100 venturi sizes-1.00, 1.10, and 1.20 inches with a common 1-7/16-inch bore. Interchangeable venturi inserts determined size-1.00 inch for the 144, 1.10 inches for 170, and 1.20 inches for the 200. This means you must be aware of which venturi size you have in your Autolite 1100. If you're running an 1100 with a 1.00-inch venturi intended for the 144ci six, you don't have enough carburetor for a 170 or 200.
4 Jon Enyeart of Pony Carburetors...
4 Jon Enyeart of Pony Carburetors has a formula he uses to get rid of hesitation and surge with 1100 carburetors. It works quite well.
5 When older carburetors...
5 When older carburetors sit for an extended period of time, today's fuels can deteriorate, leaving gum and varnish deposits that can clog small passages to cause poor performance. Note the 1.20-inch venturi insert in this 1100 carburetor. Bore size is 1-7/16 inches but Ford used three venturi insert sizes--1.00, 1.10, and 1.20 inches.
6 When you order an Autolite...
6 When you order an Autolite 1100 from Pony Carburetors, you get the complete package, which includes an instructional video, base gasket, and choke heat tube. These carburetor restorations are outstanding and certainly authentic. Should you have a problem, Jon Enyeart will help get you back on the road again.
7 This log-style integral...
7 This log-style integral intake manifold is a big reason for six-cylinder fuel distribution problems that cause rough idle and an overall lack of performance. These manifolds can be honed and ported to improve performance. Manifold end plugs can be removed for this purpose. Be assured, honing and porting does not come cheap, but it can make a difference in performance. A carburetor spacer will help torque, but watch out for hood clearance.
There are some variations in the 1100 you need to know about aside from venturi size. From '63 through '67, the 1100 carburetor (except '66-'67 California emissions) had a spark control valve (which looks like a Holley or Autolite power valve). Its purpose is to switch between intake manifold vacuum (constant) and venturi vacuum (throttle controlled) for the Load-O-Matic distributor, which does not have a mechanical (centrifugal) advance. Instead, the spark control valve applies throttled vacuum to the vacuum advance as the accelerator is pressed and rpm increases.
For '68-'69, as well as California emissions vehicles in '66-'67, the 1100 carburetor took on significant changes, including a 1.10-inch venturi in all 170 and 200ci applications. The spark control valve went away because there was a new Autolite single-point distributor with both mechanical and vacuum advance.
8 It is debatable whether...
8 It is debatable whether or not this exhaust port divider improves performance. However, it does reduce siamese exhaust port turbulence and increases velocity (scavenging), especially if you're running headers.
The 1100's automatic choke system is identical to what we find on the 2100 and 4100 V-8 carburetors with a choke heat coil and hot air manifold heat system. Hot exhaust manifold heat is drawn to the thermostatic coil, which expands with heat and pulls the choke off. A choke unloader speeds up the pull-off process to both reduce emissions and save fuel. If the automatic choke is set too lean, you will experience hesitation and stalling. The key is to adjust the automatic choke for just the right amount of choke and pull-off.
Hesitation at operating temperature usually comes from accelerator pump issues. The accelerator pump injects raw fuel into the venturi to help close the lean gap between the idle circuit and power circuit when you step on the gas. If the accelerator pump shot is insufficient, the engine will experience a temporary lean condition and hesitate. The accelerator pump's purpose is to keep the fire lit during that transition from idle to power circuit as you get underway. Autolite 1100 series carburetors are notorious for hesitation due to an inadequate accelerator pump shot and/or poor choke adjustment. It's really about proper carburetor adjustment more than anything else.
If an 1100 is adjusted properly, all you need is a 3/4 step on the accelerator pedal prior to start-up. This puts raw fuel in the carburetor throat and activates the automatic choke if the engine is cold. If it is at operating temperature and the choke is open, the raw fuel shot will aid starting. There is no need to goose the throttle on start-up. Step on the gas once prior to start-up and the engine should fire right up if everything is in proper working order.
9 Concours restorations call...
9 Concours restorations call for ignition points and condenser in the Ford Load-O-Matic distributor. Daily drivers need the PerTronix Ignitor, a compact electronic ignition module that fits inside the distributor. It improves cold start and yields a crisp response.
Ford's Load-O-Matic single-point distributor is a six-cylinder exclusive because it is different than the dual-advance distributors used on Ford V-8s. Dual-advance distributors, as the name implies, have both vacuum and mechanical advance. The six-cylinder Load-O-Matic distributor doesn't have a mechanical advance. Instead, the spark control valve channels intake manifold vacuum depending upon driver input. This is unique to '63-'67 49-state 144/170/200ci sixes, which includes most six-cylinder Mustangs out there. Where it becomes different is '66-'67 California emissions and '68-'69 49-state where Ford fit the 170/200ci sixes with a more conventional dual-advance distributor, eliminating the spark control valve and Load-O-Matic distributor entirely.
10 If you must use points,...
10 If you must use points, precision tuning is paramount. Point gap should be set with the rubbing block lubricated. Check average gap on all six lobes. Drag on the thickness gauge should be ever so slight and more on the wide side to allow for rubbing block wear. Make sure points make contact evenly and check point wear after 500 miles of driving. Check vacuum advance for proper operation.
Ignition problems are easier to understand and solve than fuel system woes. Rule of thumb is to never trust new parts right out of the box; just because an ignition wire set is new doesn't mean it's going to function properly. The same can be said for distributor caps and ignition kits. In fact, most ignition kits are manufactured offshore these days and not the same caliber they used to be. If you must use points and condenser, opt for a Motorcraft tune-up kit because they're still manufactured to the same high standards you expect from Ford. We're talking phenolic rubbing blocks and vented contact points, not the cheesy nylon stuff you find at discount stores. Spend the money to buy the best.
MCE Engines in Los Angeles has a strict regiment when it comes to the finite details of engine tuning. Marvin McAfee shows us time and again why you must never trust anything right out of the box. Marvin checks quality (material condition) and continuity (resistance or an open circuit) of every ignition part he installs. Ignition wires sometimes have breaks you cannot see. New spark plugs sometimes suffer from zero continuity (no spark) and must be discarded. And sometimes, it's as simple as a bad ground between engine and chassis, which creates all kinds of electrical gremlins.
11 Ignition wires don't get...
11 Ignition wires don't get enough attention during installation, which creates all kinds of problems. Seat the terminals firmly in the distributor cap using dielectric compound. Do the same at each spark plug. Run ignition wires as parallel and as far apart as you can to prevent crossfire. And remember, spark plugs and ignition wires can fail at any time. When there's a misfire, begin your troubleshooting here first.
When engines develop a misfire, it's easy to assume the worst. Instead, Marvin suggests going after the simplest things first. Most of the time, misfire comes from faulty ignition components. Marvin stresses the use of genuine Motorcraft or Autolite spark plugs and ignition components, advice that comes from experience with a wide variety of ignition parts.
Three For Six
When the compact Ford sixes were introduced 50 years ago, aftermarket companies like Offenhauser got on board with performance products designed to improve performance. The three one-barrel carburetor setup was one approach using Holley or Autolite carburetors. Those classic Holley 1904, 1908, and 1909 one-barrel carburetors look sharp and perform well when you can find them. Pony Carburetors is the first stop in your search because they have a huge inventory of cores and access to a vast network of sources if it isn't in stock.
The Holley 1904 carburetor, introduced in 1952, was used primarily on the 223, 240, and 300ci sixes. The 144 and 170 got the Holley 1908 carburetor with a glass bowl. The 1909 carburetor was introduced in 1962 atop the 144 and 170 with an automatic choke. You also have the option of three Autolite 1100 series carburetors for the Offy induction system.
The Offenhauser 3/1 induction system doesn't necessarily deliver trailblazing performance. It does improve fuel/air distribution, placing two carburetors toward each end of the log-style intake manifold to improve drivability while offering crisp response and a steady application of torque under acceleration.
Summit Racing Equipment has the classic Offenhauser induction system for vintage Ford sixes, part number OFY-5205, which includes the three one-barrel manifold, attachment hardware, gaskets, and progressive linkage. It does not include the carburetors, which can be sourced from Pony Carburetors or Mustangs Etc.
Redline Cooling offers high...
Redline Cooling offers high caliber radiators and electric cooling fans at prices well within most budgets. These guys are designed specifically for classic Mustangs with sixes and V-8s--with and without electric fans.
We don't hear much about overheating with six-cylinder Mustangs because they had adequate cooling systems from the factory, unlike their V-8 counterparts. Still, if factory cooling is adequate, you can do even better with a three or four-row core radiator, high-flow water pump, and proper cooling fan configuration.
Mustangs Plus offers a nice array of three and four-row core copper/brass radiators for six-cylinder Mustangs. They also have Scott Drake high-capacity, aluminum radiators for six-cylinder Mustangs. We've also worked with Redline Cooling, which offers custom and mass-production aluminum radiators for classic Mustangs. Redline's cooling capacity is unequalled, offering enthusiasts outstanding radiators at reasonable prices.
When you're planning your Mustang six's cooling system, plan for extreme conditions at each end of the heat spectrum. Although some opt for a 160-degree thermostat, we recommend a 180-degree thermostat because you want your six to operate warmer rather than cooler. Cold engines aren't as efficient for one thing. For another, lubrication doesn't perform as well in a cold engine. Replace your Mustang's thermostat every two years, which is when cooling system service (flush, fresh antifreeze) is suggested. Replace hoses every four years, and always use an anti-collapse spring in the lower hose.
Mustangs Plus offers high-quality...
Mustangs Plus offers high-quality Scott Drake aluminum radiators for classic Mustangs. If your desire is to keep a stock demeanor, you can always paint an aluminum radiator satin black while getting improved cooling capacity.
Fan type and configuration...
Fan type and configuration are very important choices. The most efficient type of engine-driven fan is the thermostatic clutch fan, which engages only when you need it. Second best is a flex fan, which becomes more aerodynamic with engine speed. Use of a fan shroud is also important because it improves air velocity and flow across the radiator. Fan depth should be half way into the shroud for optimum cooling.
There are several schools...
There are several schools of thought when it comes to coolant. Water is the most effective coolant. However, corrosion issues make pure water unrealistic. The use of water with a corrosion inhibitor works for optimum heat transfer, but isn't popular with most. One engine builder suggests 100-percent antifreeze to prevent corrosion and freeze-ups. Although pure ethylene glycol doesn't transfer heat as well as water, it does transfer heat without corrosion issues if you have a high-capacity radiator. There's also Evans non-aqueous coolant, which is used all by itself without water. It is very expensive, but never needs to be replaced.
Duraspark For Reliability
In the mid-1970s, Ford introduced Duraspark ignition on all new cars and trucks. Consisting of electronic distributor, high-output ignition coil, and a control module, Duraspark is easy to install and live with. Classic Inlines offers Duraspark ignition from Performance Distributors for six-cylinder enthusiasts. The cool thing about Duraspark is parts availability everywhere. If Duraspark fails, help is as near as the closest auto parts store.
Keep in mind the Duraspark distributor is only for Autolite 1100 carburetors without spark control. Vacuum for the spark advance comes from throttled carburetor vacuum only, never straight off the intake manifold. Manifold vacuum is constant; throttled vacuum happens only when you step on the accelerator.
Duraspark gets its power from non-resistance power right off the ignition switch-a full 12-14 volts-not from resistor wire (pink) that steps power down to nine volts. You can mount the control module just about anywhere, including under the dash if you prefer a stealthy approach. Painless Performance Products offers a Duraspark conversion kit that makes installation a snap.
Building Tips
When it's time to build a six, here are some important points to remember. If you're shopping for a block or rebuildable engine core, check casting numbers. Ford manufactured two basic types of small six-cylinder blocks-four main bearing and seven main bearing. Unless casting numbers and date codes are important to you, you want the seven main bearing block and crankshaft. All 170 and 200ci Mustangs had seven main bearing sixes.
This is the seven main bearing...
This is the seven main bearing 200ci six-cylinder block. Most 200 blocks are seven main bearing, with the exception of its first year, 1963, where 200ci sixes had the 144/170ci four main bearing block. Ford redesigned the lightweight sixes to seven main bearings to reduce noise, vibration, and harshness. Four main bearing blocks can be identified by three freeze plugs. The seven main bearing block has five.
McLearran Motorsports of Tucson,...
McLearran Motorsports of Tucson, Arizona, builds the fastest Ford sixes in the country. They use cylinder head and main cap studs for extraordinary strength and security.
Rebuilds should always include...
Rebuilds should always include hardened exhaust valve seats along with intake manifold clean up and port work to improve performance. These are good stealthy mods no one can see.
Installed correctly (meaning...
Installed correctly (meaning water passages at the rear), Fel-Pro Print-O-Seal head gaskets are your best bet against a blown head gasket. Make sure your machine shop checks deck trueness and gives it a shave during the machining process. Ditto for the cylinder head.
JGM Performance Engineering...
JGM Performance Engineering uses Viton valve seals instead of umbrella or Teflon. Viton seals offer unequaled durability on street and strip engines.
You can go one of two ways...
You can go one of two ways with stock six-cylinder rocker shaft assemblies--adjustable rockers and cup pushrods or nonadjustable and round-tip pushrods. The nonadjustables were designed for hydraulic lifters, which means you need a specific pushrod length. Adjustables are intended for mechanical lifters.
Cam selection is dictated...
Cam selection is dictated by how you intend to use the engine. Daily drivers don't need radical cams. Instead, they need a cam that delivers low- to mid-range torque for drivability and a smooth idle.
Another item often overlooked...
Another item often overlooked is engine blueprinting. Every camshaft should be degreed to determine real specs versus cam card numbers. Combustion chambers should be cc'd. Volume above each piston at bottom dead center should be checked. Rings should be dressed. Clearances should be checked everywhere.
Rear main seals should have...
Rear main seals should have their gaps staggered away from the main cap to block parting lines. Sealer should be used sparingly.