Mustang Chronicles: Gathering Parts

My simple job to replace a thermostat on my 1965 Mustang turned into this: 

(Ford 200 I6 engine block with new gasket before cylinder head install)

I broke a bolt off in the original cylinder head housing and had to drill it out.  My amateurish attempts to rethread the hole with an old tap and die set proved fruitless, leaving me stuck somewhere between my propensity to optimistically dive headlong into a project, and the limits of my skills.  So it seemed like a good idea to double down on optimism and take the opportunity to do some engine upgrades.   

The biggest shortcoming of the early six-cylinder Mustangs is the design of the intake manifold, which is cast as part of the cylinder head.  Ford decided they could save real money that way, but it results in an engine that breathes like a hamster with emphysema.  In 1968 Ford enlarged and improved the intake manifold and added larger valves in 1977.  The intake manifold looks a bit like a log, so pre-1968 heads are known as "small logs" and the 1968 and newer ones are "large logs".  Production of the engine spanned from 1960 to 1983 and it was used in just about all of Fords smaller/economy vehicles. 

(Remanufactured "large log" cylinder head from a 1973 Maverick)

The Ford 144/170/200 inline 6 will never be in the same league as the Toyota 2JZ or BMW N54 for performance tuning.  In various guises it makes between 90-120 gross horsepower.  But it's a stout engine, and it's possible to increase power output by 30-50% fairly easily and cheaply.  

In my case, it was cheaper to buy a large log cylinder head than have my old one rebuilt.  From there, I decided to also upgrade the carburetor and distributor with the goal of making 20-30 more horsepower.  Here are the details for my build:

• Remanufactured 69-79 Ford 3.3L 200ci L6 w/ 1 3/4" Carb Throat C9/D3/D5/D7 Cylinder Head from Allied Motor Parts. This head came from a 1973 Ford Maverick, but has the larger intake valves.  All Allied does is cylinder heads and they ship nationwide.    

• New Carter YFA 1 barrel carburetor from Mike's Carburetor Parts.  Mike's specializes in carburetors and has a lot of great technical and troubleshooting articles.  They do quality work and are made in the USA.  There are lots of options for carburetor upgrades on the Ford inline sixes, including two barrels using an adapter or modified cylinder head.  This article on Classic Inlines provides a wealth of options and information.  I chose the Carter YFA for the following reasons:

• I wanted something that would work with a "stock" engine, provide good low end torque and drivability on the street, and be reliable and easy to maintain.    

• I am not ready to modify the intake for a two barrel, or do a performance build on my engine.  I also didn't think a two barrel adaptor would provide better performance than the Carter 1 barrel, and I'd lose some of the drivability. 

• The Carter YFA was the standard carburetor for 1969 and 1970 inline 6 engines and a good match for the larger log head.  It was also standard on Ford's 240 and 300 cubic inch truck engines until Ford switched to fuel injection in the 1980s.     

• New Performance HEI Distributor - Besides the large log head, the biggest performance upgrade is to replace the Load-o-Matic distributor with a Duraspark or DUI distributor.  This HEI distributor got good reviews and was 1/2 to 1/3 the cost of either the Duraspark or DUI.  NOTE: You will need to replace the Load-o-Matic distributor if you swap out the Autolite 1100 carburetor because the LoM does not have a mechanical advance.  This article on Load-o-Matics from Classic Inlines will tell you everything you ever wanted to know.  .     

• New ARP Cylinder Head Studs from Vintage Inlines - these are overkill, and are 10 times stronger than the stock head bolts.  But after breaking bolts on several other parts of the engine, I felt the cost was good insurance, especially if I decide to tear down the engine again someday. 

I also bought the Ford Inline Six Performance Handbook.  This book is required reading if you want to rebuild and modify Ford inline six engines.  There is also a wealth of great information and knowledgeable people on the FordSix community website, who also maintain the links to the Classic Inlines tech info pages.  Finally, if you plan to work on one of these engines, please patronize Vintage Inlines, who are the go-to source for all things Ford inline 6.

Over the next few weeks, I plan to write about installing the cylinder head, setting up the carburetor and distributor, and any other tasks needed to get my Mustang back on the road.  

Mustang Chronicles: The Slippery Slope of Car Repair

 

What started as a 15 minute repair has turned into a downward spiral.  The Mustang started overheating, so I went to my local auto parts store and bought a new thermostat, temperature sensor, and coolant flush kit for about $30.  I about had it all back together, but snapped one of the new bolts, as I was tightening it with a torque wrench.  The bolt broke almost flush with the cylinder head, making it impossible to remove with vice grips.  

Broken bolts are a fact of life when working on an old car, and the early Mustangs seem especially prone to breaking bolts on the thermostat housing and exhaust manifold.  I ended up removing the radiator and drilling out the broken bolt, thinking I could clean out the threads in the cylinder head with a tap and die set.  

Unfortunately, I could not clean out the threads, or may have stripped them.  In any case, I knew I had more broken bolts ahead of me, because I was planning on replacing the cracked exhaust manifold, which also bolts on to the cylinder head.  My plan was now to removed the exhaust manifold and then send the cylinder head out to be reconditioned.  

That put me on the slippery slope of car repair, the one where you start with the intentions of doing a small repair job, only to slide down into the abyss of a full on rebuild.  I found a good engine shop, which quoted me about $400 to redo the cylinder head.  This would mean the Mustang would have the top half of the engine rebuilt, while leaving the pistons, bearings, camshaft, and crank untouched and original to a 56 year old car.  Should I do a full engine rebuild while I'm at it?  Do I leave the engine stock, or make some modifications to improve performance?  In addition to the engine itself, should I upgrade the carburetor and ignition?  How far do I want to go?  

Sometimes deciding what to do can be harder than actually doing it.  

 

Yeah, It’s Got a Six

“Hey, is that a ‘65 Mustang?  What-cha got under the hood?”

Those are the most common questions I get when I’m out in my Mustang. Most people don’t care when I tell them the car has a six cylinder engine, but a good number of people seem disappointed.  

Known as the Thriftpower or Falcon 6, the engine displaces 200 cubic inches (or 3.3 liters) and produces 120 horsepower and 200 lb. feet of torque. It offers acceptable performance with good drivability - so much so that the engine was used into the 1980s and powered in a variety of Fox body vehicles, including the early 3rd generation Mustang.

For people looking for more power there are a number of options including swapping out the one barrel Autolite 1100 carburetor for any variety of two barrel options or fuel injection.  Additionally, there are a range of exhaust headers, electronic ignition, cams and cylinder head modifications. Choices range from mild improvements for daily driveability, all the way to wild options like an Offy tri-carb setup and turbocharging.  

Early on, the six cylinder Mustang got an undeserved reputation as a “secretary’s” car.  But a Mustang with a six cylinder and manual transmission compares very favorably to many European cars of the same era.  Look at the performance specs for the Austin Healy 3000, Porsche 356C, or similar 2 + 2 coupes - the Mustang is either within striking distance, or puts up better numbers.

Best of all, a first generation, six cylinder Mustang has balance.  It is a throwback that provides equal doses of fun and practicality.  You can drive it daily and it is rewarding to drive across town on errands or cross country. You can work on it with a basic set of tools and a general understanding of auto mechanics. It can be your weekend car, or your only car.  It is approachable, doesn’t ask for much, but in return gives a purely analog driving experience.  

There are faster cars.  There are better cars, with more of everything.  But there are few cars that convey the joy of unbridled youth, of turning 16 and getting your license, and hitting the road on a spring day, with the windows down and the radio on.