Last winter was eternal, making it difficult to work on the car. This blog fell by the wayside. A benevolent spring brought opportunity to get back on track. There is much to recall.

To begin, the engine, which had been running nicely, developed a serious problem. Back when I installed the new fuel tank, I had drained the old tank of the sludge and some old leaded gas. I filtered the gas, about two gallons, and stored it. Being the responsible sort, I didn’t want to pour the gas out onto the ground and, thinking it could do no harm, mixed it 50/50 with the unleaded gas the engine was running on.

Soon thereafter the engine began to run badly, coughing and sputtering. Spark plugs became fouled. Even after cleaning the plugs the engine wouldn’t run on all cylinders.

Removing the valve covers revealed several bent pushrods.  Removing the heads revealed blackened pistons. Valve stems were coated with a varnish-like gummy residue.

Bent Pushrods (click to enlarge

Bent Pushrods
(click to enlarge

Blackened Pistons  (click to enlarge)

Blackened Pistons
(click to enlarge)

Fouled Valve (click to enlarge)

Fouled Valve
(click to enlarge)

All the valves had to be disassembled from the head and cleaned. Indeed, some of the valves were frozen in their guides by the “varnish.” Those had to be soaked overnight in lacquer thinner and tapped free with a rubber hammer.

I also partially disassembled the carburetor, carefully cleaning out all passages with denatured alcohol and compressed air.

Luckily, the one silver lining is that the engine was being fueled via a gas can attached to the fuel pump – my new gas tank was uncontaminated.

The remaining task was to replace the bent pushrods. Old Ford engines don’t have a screw on the rocker arm to adjust valve lash to the pushrod length. With a Ford engine the pushrods must be of predetermined lengths, measured and selected such that there is no valve lash. Having to do that and not confident about the state of the old lifters, I decided to upgrade to a new hydraulic roller lifter and camshaft system.

Installation of the new cam system required a series of accurate measurements (with the engine removed from the car), to be discussed in an upcoming blog post.

 In view of my wife’s opinion* (outrageous!)  that I’m accident prone (what about mitigating circumstances?), I endeavor to take a most overcautious stance regarding work safety.  So, to this point the engine has been running with fuel supplied from a gas can connected to the fuel pump hose. There’s no gas in the gas tank yet. That’s because I’m completing body repairs in the rear of the car. Welding and grinding creates heat and sparks — very dangerous near gas fumes.

Most of the body of the ‘66 Thunderbird is double-walled, with exterior and interior walls welded together at the edges, forming a strong structure resistant to bending and vibration. The downside is that (1) it makes the car very heavy and (2) water and moist dirt have a tendency to become trapped in between the walls at the bottom joints causing rusting from the inside to the exterior surfaces of both walls.

The accompanying diagram shows the left wheel well area.


Rust Repair Process

In this case the rust had eaten through both walls and also weakened the structural integrity of the wheel well curvature.  It’s best to make repairs to an acceptable standard of industry practice. In cases where rust has completely eaten away the metal, I start by cutting away the rusted areas leaving solid metal,  then welding in new sheet metal using a MIG welder.

In this particular area, cutting away the rust left nothing to weld new metal to.  Also needed was a solid restoration of the wheel well curvature.  For that I used a length of ¼” square rod, bent to the wheel well curvature and welded to where the existing metal was still solid.

Before welding in new metal, the existing metal is thoroughly cleaned of rust and treated with Eastwood™ Rust Converter to ensure that the area won’t oxidize further. (Note that the Rust Converter is great stuff but, at about $32/quart + shipping, is expensive.) Once the new metal is welded in place the weld spots are smoothed with a grinder. Next, Bondo is applied and sanded smooth (repeating until the surface conforms perfectly to body contours). Rubberized undercoat is applied to the interior joints and wall surfaces to seal them from moisture so that they never rust again. The undercoat also serves to quiet the car. Then the exterior surfaces are primed and painted.

Door prior to disassembly.

Door prior to disassembly.

Door Disassembled

Door Disassembled

The car doors had been removed in order to have access to the car’s interior and to make it easier to restore operation of the windows and locks. The rust on the doors was not as severe as the rear quarter panel discussed above.

In this case the rust had created pin-holes in the metal but didn’t eat away enough of the metal to require new metal inserts. To repair pin-holes, both sides of the panel are sanded then treated with Rust Converter. A fiberglass patch is applied to the interior of the panel, followed by a thin coat of Bondo on the exterior. The interior is undercoated.

Door interior bottom showing dirt and trash that cause rust

Door interior bottom showing dirt and trash that cause rust

Interior of door, cleaned, treated and sealed.

Interior of door, cleaned, treated and sealed.

If you’re doing this for your own car there are two products I recommend that will save money. To seal joints, apply with a brush Henry™ Plastic Roof Cement (available from Home Depot for about $9/gallon). The other product is the Rubberized Undercoating available from Harbor Freight, less than $5 for a large spray can.



*Do note that I adore my wife. Although I portray her in the She-Who-Must-Be-Obeyed stereotype, that is merely a literary device. She is without doubt the best that’s ever happened to me. For too many years I avoided getting married, living a life of international travel and the freedom to adventure as I pleased. That’s a great life for a young man, but along the way I met men like me who had grown old, bitter, and lonely because they never married. The woman who is now my wife rescued me from that fate.


As you can see from the video, the engine starts and runs fairly smooth. It took a long time to arrive. In addition to a few mechanical problems, there were family exigencies to attend to during the summer.

Actually the engine first started in late July, but noticing that there was no oil circulating through the rocker arms I immediately shut it off. I now know that it’s important to prime the oil system prior to initial start. To do that with the engine not running, one removes the distributor and operates the oil pump with a priming tool, which is just an extension of the pump shaft attached to an electric drill.

It still needs to be tuned up and to do that the car needs to be drivable. That requires further reassembly of the car. Much of that reassembly had been put off until I was confident the engine would not have to be removed to correct an as yet unforeseen problem.

So, moving forward the next near-term milestones will be:

• Complete painting of car interior
• Finish restoration of dashboard
• Install dashboard, instrumentation,
• Reassemble steering column and install
• Install driver’s seat
• Connect shift linkage
• Remove remaining surface rust from underbody, seal and undercoat.
• Re-plumb brake system, install and test brakes
• Mount tires and test drive train
• Fine tune engine

It’s been about a year now and, judging by the pictures below, you might think that there hasn’t been much progress.  It’s just that there is so much prep work that goes into the foundational elements.  As a typical example, you can’t run the car without gas, but the trunk had to be repaired before the gas tank could be installed.  And every task seems to take twice as long as predicted.

But now we’re finally at the point where the focus is starting the engine So all  the hoses, wiring, and linkages are being reinstalled.  The starter has been installed and tested — it turns the engine freely and  there are no oil leaks.   Hopefully, my next post will be a short video of a running Ford 390.  Stay tuned.  Cheers!

(Note that clicking on any picture will enlarge it to full size.)

The [mostly] reassembled engine, ready for installation  (click to enlarge)

The [mostly] reassembled engine, ready for installation
(click to enlarge)

Recent progress was marked yesterday when my brother Erik and I moved the engine from the sunporch in my house to the work area next to the car.  Moving the stripped engine block to the sunporch had been a relatively easy one-man job.  But after installing crankshaft, pistons, heads, intake manifold, et al, the combined assembly weighed considerably more.  Strapped to a hand truck, it required the use of a floor jack just to tip it back so it could be rolled outside.  Then we used the floor jack to tip it back upright.

Other progress has been made prepping the car for the engine installation.

The interior of the car has been scraped, sanded, primed and sealed.  Special attention is being paid to upgrading the soundproofing using modern materials.

We  removed the doors to make access in and around the car easier.  It’s also easier to work the doors on a bench surface rather than on the car, and makes it easier to prime and paint the door jambs and fenders.

The old heating unit has been removed and the combined air conditioning/heating unit procured and awaiting installation.

The gas tank was removed for cleaning and sealing. The tank drained a few gallons of decades old, rusty gasoline sludge.   The sending unit was rusted out and will be replaced with a new one.  I’m cleaning the inside of the tank by inserting a heavy chain and sloshing it around in muriatic acid.  When the rinse comes out clean, the tank will be dried and sealed with a product called Red Kote.

Removal of the fuel tank allows access to the car underside so that rusty surfaces can be treated and sealed.

Cylinder Head Cross Section (click to enlarge)

Cylinder Head Cross Section (click to enlarge)

Cylinder heads are the gateways to and from the combustion chambers formed by the pistons in the cylinders.  As the crankshaft turns, cycling the pistons up and down in the cylinders, it also rotates the camshaft, which in turn synchronizes the opening and closing of the valves, 2 valves per combustion chamber. One valve opens the passage for fuel to enter the combustion chamber. The second valve opens to allow waste gasses (exhaust) to exit the chamber.  The valve seats(shown red in the diagram) are the areas where the valves contact the head to close the passage.

The valves cycle open-and-close in a “4-stroke” combustion sequence, as shown in this animation. 4StrokeEngine_Ortho_3D_Small

  1.  The first valve opens to allow the fuel aerosol coming from the carburetor into the combustion chamber.  Then it closes.
  2.  The piston comes up, compressing the fuel aerosol.
  3. The spark plug ignites the fuel causing it to explode, forcing the piston back down.
  4. Now the second valve opens up a path to the exhaust pipe.   As the piston comes back up, it pushes the exhaust gases out.  The second valve closes.

The cycle keeps repeating (until you turn off the engine). 

The stock 1966 cylinder heads for the T-bird are made of iron. The valves are made of steel.  One of the reasons that tetraethyl lead was added to gasoline back then was that it lubricated the valve seats to keep them from wearing out too quickly. 

Since leaded gas is no longer available, running the engine with the old heads would require that a lead-like additive be mixed with the unleaded gas at each fill-up.  (EPA probably doesn’t even allow that anymore.)   So, in order to run on unleaded gas the old heads must be retrofitted with valves made of stainless steel and the valve seats coated in a modern alloy such as stellite.  But since that’s expensive, for just a few dollars more (and less logistics) an even better solution is to just replace the heads with modern aluminum heads, which are designed to run on unleaded.  And there are other advantages to aluminum heads.

Aluminum heads weigh significantly less than iron heads.  Less weight means better gas mileage. 

Aluminum conducts more heat than iron – four times more.  Temperature control is the function of the cooling system, which uses a thermostat to regulate coolant to flow through the engine, keeping it at a near-constant temperature.  For iron cylinder heads the thermostat is set to operate at about 180°F.  Above 180°F, the thermostat allows coolant to flow through the engine, cooling it down; below 180°F the thermostat closes, keeping the engine from becoming too cool. 

Aluminum heads assist in conducting excess heat away from the engine block, preventing runaway temperature increases beyond the capacity of the cooling system to handle, making it feasible to run the engine at a higher temperature.  Therefore, a thermostat set to operate at 195°F can be used.  The improved conductive efficiency of the aluminum heads transports heat away from the block allowing for the engine to be run at the higher temperature. The higher engine temperature increases the fuel aerosol pressure in the combustion chamber. The increased chamber pressure results in a more complete fuel burn.  This, in turn, creates:

  •   More power
  •   Better gas mileage
  • Reduced exhaust emissions

For those of you in the market for a fast classic, here’s a Ford Cobra Torino concept car in mint condition, built for speed. 

1970 Ford Cobra Torino Concept car

1970 Ford Cobra Torino Concept car

And it’s yours for a mere $550,000.  Click this link for more views of the car.   

First, the progress.  Some of the hydraulic lifters were rusty, and all were generally sticky.  A few of the lifters wouldn’t come apart through normal means.  I discovered that by heating the lifter body with a plumbing torch, the oil inside would expand, popping the lifter piston free (actually launching them into low earth orbit: Houston, we are Go!).  After getting them all apart, I cleaned them, tested them for smooth operation, and installed them in the block. 

Hydraulic Lifters before and after

Hydraulic Lifters before and after

The other messy job was cleaning the rocker arm assemblies.  The bar supporting the rockers is actually a hollow tube that transports oil to the rockers.  The plugs in each end had to be removed and the gunk inside cleaned out.  

Meanwhile Scott, at Mr. Transmission  (Decatur, GA; 404-921-0028),  completed the overhaul of the C6 automatic transmission.  Scott and his crew deserve kudos for their expertise and interest in the restoration project. Generally transmission shops have a bad reputation, but Scott has always been honest, clearly explains problems and options, and charges a reasonable amount for repairs.  He also offered to delay the start of the warranty period from the time the C6 is actually installed in the car and included free operational check and adjustment of the C6 once the car is drivable.  If you need transmission maintenance or repair, I highly recommend him.   

The new Edelbrock aluminum cylinder heads had been bolted on (see previous post).  The next step was to install the Edelbrock aluminum intake manifold.  It was at this point that the project was beset by a plague of delays.  

I was unable to torque the bolts securing the intake manifold to the heads.  The two rear bolts wouldn’t “bite.”  That is, the bolts just rotated without tightening further (and that “bites” a bear’s butt!).  When I removed the bolts there were pieces of aluminum thread from the cylinder head on the bolt thread.  That shouldn’t happen at the low torque applied (25 ft/lb).  I had to remove the intake to inspect the bolt holes, which damaged the gaskets, which had to be replaced. (Edelbrock, are you listening?) 

I called Edelbrock tech support and they suggested I use the Edelbrock bolt set. So I purchased a set: in fact there is no difference between the length or thread of the Edelbrock bolts and the bolts I was using.  I grant that the Edelbrock bolts are prettier.  After three more calls to tech support, they agreed to send me a few heli-coil inserts to repair the bolt holes in the head. As well as a customer satisfaction issue, I fault Edelbrock for not showing an acute investigative interest in what may be a quality control problem in their manufacturing process.

Given the circumstances, I reckoned it prudent, long term, to insert heli-coils in all ten bolt hole locations.  No doubt this jeopardizes the warranty, but what other reasonable option?  With trepidation and much angst, I carefully drilled into my $1600 set of Edelbrock heads and tapped the threads for the inserts.  As it turned out, the retrofit was successful and the heads and intake manifold will shortly be reassembled onto the block.

The aforementioned process occurred over a period of several weeks, so in the interims I began rebuilding the 4-barrel Holley carburetor.  The carb is one of the most complicated devices on the car.  It operates on principles of pressure differential, Bernoulli’s law, and the Venturi effect. Complexity withstanding, overhauling the carb is simply a matter of taking it apart, cleaning out the carbon build-ups, using the air compressor to blow out all the fuel/air/vacuum passages, and re-assembling it with new parts and gaskets.  

I ordered the rebuild kit from Daytona Parts.  By mistake, the first kit that they sent was for a 2-barrel carb.  The Daytona folks were very kind, and sent me the correct kit plus a paid return envelope to send back the 2-barrel kit.  However, near the end of the rebuild I discovered that one of the gaskets in the new kit was the wrong size.  Knowing this would be difficult to explain over the phone, I scanned the gasket image into my CAD software, added dimensions showing the discrepancy, and emailed it to Daytona.  They concurred with my observation – turns out they’d sent a variant version of my 4-barrel kit.  Again, they were very apologetic and express shipped a new, correct kit.  Happily, despite the minor delays, none of these iterations cost a dime more than the original price.  

Remaining tasks of  the engine reassembly are:

  • insert lifter rods
  • attach timing chain cover and harmonic balancer
  • bolt on water pump
  • insert distributor assembly
  • bolt on exhaust manifolds
  • flywheel
  • mate engine with C6 transmission

To prevent possible damage to carburetor, alternator, power steering pump, and fan, they’ll be attached after engine installation.   In parallel to engine reassembly, the car itself has been worked on in preparation for receiving the engine.  The engine bay was rewired; the dashboard and associated engine controls have to be renovated and reinstalled; cooling system readied; the exhaust system is being worked on; brake system overhauled; etc.

So stay tuned — the fun just never ends!





At this point the crankshaft has been rebalanced and installed.  A detailed explanation of the balancing technology will be posted soon-ish.

Pictures and drawings of parts of the car may leave the audience wanting to see what the finished product would look like.  So I searched the internet and found a photo of a similar T-bird in the colors this project envisions.



Click to enlarge

Naturally the finished car will have <!–more–>a kick-butt stereo system.  To that end I created a car-themed playlist of music that I have in my library.  The selections are mostly ’80s-’90s and predominantly rhythms that could be considered a hazardous factor in excessive speed, conducive to making the acquaintance of the highway constabulary.   A proper list should also  include The Little Old Lady From Pasadena and other car songs by Jan & Dean, the Beach Boys’ 409.  et al.  Using the Comments form, feel free to suggest your own fave paeans to the Cult of the Dinosaur Burners and/or hymns to the Holy Order of the Sweet Chariot.

After installing the crankshaft, the pistons were assembled with connecting rods and rings.  The rings are circular bands of metal with a diameter slightly larger than the piston. There is a gap in the ring that allows the ring to be squeezed into the cylinder, and the ring is ‘springy’ so that it always presses tightly against the cylinder wall.  Each piston has three levels of rings: two compression rings and a set of oil rings.  The purpose of the rings is to seal the compression chamber made by the piston within the cylinder so that a) no combustion gases leak downward out of the compression chamber and b) no oil leaks upward into the compression chamber.


Ford ring gap illustration. (Click to enlarge)


Piston rings as installed. (Click to enlarge)

Yet even when compressed there is still a tiny gap in each ring through which leakage can occur.  Therefore the  ring gaps are staggered around the piston to minimize leakage.   The Ford manual illustration showing gap positioning was cryptic, so I researched the topic on the web.  There is much disagreement on car club web sites as to correct orientation of the rings gaps. What everyone agreed on is that the gaps in the rings should not line up vertically on the piston, allowing a direct path for leakage.  The disagreement is about where on the piston the gaps should be positioned.   After indecision and consideration of the competing advice, the Ford manual suddenly made sense.


Engine block showing installed pistons and left side Edelbrock aluminum head. (Click to enlarge.)

Having sorted that out, the pistons are now installed.  The new Edelbrock aluminum cylinder heads arrived and have been bolted on.

I’d rebuilt only one engine prior to this project.  It was a straight 6-cylinder for a 1958 Ford step-side pick-up.  The truck was purchased circa 1985 for my direct mail advertising venture, used for hauling mail to the main post office.  There was often so much mail that the front wheels were in danger of lifting off the road, which when added to the excessive steering wheel play made for hair-raising trips.  It also burned more oil than gas — I kept gallon milk jugs of used motor oil on board (free from service stations) to sate its daily appetite.

Stepside Clyde, the Wonder Ride

Stepside Clyde, the Wonder Ride

At the time, I lived on a rural six acre plot with 2 chicken houses, hog house, barn.  I extracted the engine with a come-along hooked to the rafters of a chicken house.  The rebuild was very basic and low tech. Didn’t re-bore the cylinders and the original pistons were re-used.  Only the rings, standard bearings, and gaskets were replaced.  Reassembled in the truck, I was shocked when it actually started and ran (didn’t expect it to).

The truck was rather ugly, but that was its distinction.  I named ‘him’  Stepside Clyde and we stuck together through many a woman.  Even though I had a new Jeep, the truck was fun to drive and I kept it for several years.

Exploded view of crankshaft-to-engine block assembly.  Engine block is inverted, as it would appear mounted on its work stand (removed from the car).

Exploded view of crankshaft-to-engine block assembly. Engine block is inverted, as it would appear mounted on its work stand (removed from the car). (Click to Enlarge)

Ah…but we digress.

As Jeff Foxworthy reminds us, if you’ve ever had to move an engine so your wife could take a bath, you might be a redneck. So, after swearing on a stack of Cosmopolitan magazines that reassembling the T-bird’s 390 was a clean endeavor that need not preclude feminine ablutions,  I received the blessing of  She Who Must Be Obeyed to bring the engine block onto our sun porch, all warm and dry.

After sliding the camshaft into position, the next step is to install the main and connecting rod bearings.  Each set of bearings should be measured for clearance (or gap) between the bearings and the crankshaft.  This clearance should be just enough to allow the crankshaft to rotate within a circular cushion of oil, without touching the bearings. (See cross section diagram below.) Too narrow a gap risks metal-to-metal contact, which can lead to 1) burnt bearings,  or 2) actually causing the bearings to be ‘spun’ out of their seats.  Too wide a gap risks a drop in the oil pressure needed to sustain the cushioning effect.


Cross section showing crankshaft rotating inside bearings on layer of oil. (Not to scale)(Click to Enlarge)

 The easiest method for measuring bearing clearances is to use a thin string of wax called a Plastigage. After bearing halves have been installed in the engine, the crankshaft is positioned onto the bearings. A piece of Plastigage is placed on the crankshaft journal and then the matching bearing half (installed in its cap) is bolted on top and torqued to specification.  Now when the cap is removed the wax string will have been squashed flat.  Clearance is determined by measuring the width of the flattened Plastigage using the paper reference provided.   The wider the Plastigage is flattened, the narrower the gap.

Flattened Plastigage strip after top bearing cap removed. The paper measuring tool is part of the Plastigage packaging.

Flattened Plastigage strip after top bearing cap removed. The paper measuring tool is part of the Plastigage packaging.(Click to Enlarge)

These are the results of my main bearing measurements (in inches, front to back order).

  1. .002 to .003
  2. .003
  3. .0015 to .002
  4. .002
  5. .002 to .003

The Ford manual specifies that clearances should be between .0005 and .0025 inches. However, even though a few of the above results are at or above tolerance, the expert consensus is that these clearances are acceptable, even preferred.  Also acceptable were the 8 connecting-rod bearing gaps, each measuring about .001 inches.  The next step is to have the crankshaft rebalanced, which will be the topic of the next post.