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Here are the before and after shots of the ’53 Ford
Flathead rebuild performed by Tony Smith.
While discussing the meticulous rebuild of this early ‘50s Ford Flathead V8, engine builder Tony Smith brought up an interesting argument with regards to cleaning major components.
Of course, a thorough cleaning is necessary before any machine work or assembly, and not just to keep previous gunk from clogging oil galleys or loose metallic particles from invading bearing surfaces. A good cleaning will help expose cracks or other imperfections that could jeopardize a successful rebuild. And a clean block also keeps contaminates from harming machine equipment.
Here are the block, heads and intake manifold after thermal cleaning. A thorough cleaning allows closer inspection, which revealed one small crack that was easily repaired.
From left: The factory connecting rods have integral bolts, so no ARP 2000 upgrade. Smith, however, did swap on stronger nuts. Obviously, the big end of the rod was slightly elongated from wear and tear on the engine. The integrated bolts also meant the mating surface of the bearing shell on the rod itself could not be surfaced, so extra metal was taken off the cap. Then the big ends were honed to size. Smith also bored the pin ends to ensure proper alignment between the two ends and also honed the bushings to fit the new piston pins.
The block was honed and the cylinder heads were resurfaced.
Of all the cleaning options, Smith is a big fan of thermal cleaning followed by shot blasting. Other choices include hot tanking, flame ovens, ultrasonic baths, jet spray, steam cleaning and even a few cans of oven cleaner and stiff brushes. They all have pros and cons, and the types of engines that come through the shop will somewhat dictate the cleaning method as aluminum is treated differently than iron. There are also environmental factors to consider as some cleaning methods rely on caustic or even toxic solutions to complete the job.
Smith assembled the rods with bearings to take measurements so proper instructions could be given to the grinder, who freshened up the stock crank.
The pistons are from Speedway Motors and were fitted with pre-gapped rings.
Thermal cleaning involves heating the parts up to 600 degrees F in an oven, which turns all organic matter—including paint and sludge—into a fine ash. The parts are then moved to a different operation where small stainless-steel shot is blasted on the metal to clean off the ash, leaving the surface looking practically new.
“It’s real fine stainless shot capable of removing everything,” explains Smith. “But if you don’t bake the block first, there’s the potential of sludge or oil that would trap the shot, which could wash out into the bearings.”
Top and bottom views of the rotating assembly in place.
Clockwise from top left: The original 2-piece valves were well pitted on the exhaust side, and the intakes had serious face recession. The intakes were replaced with Manley small-block Chevy stainless-steel exhaust valves that needed only a little resizing. The undercut design improved flow as did the backcut angle. The were joined with standard 1-piece replacement exhaust valves. The heads also received a 3-angle valve job for both intake and exhaust.
Smith still follows up with brushes to get inside oil galleys. One possible downside to thermal cleaning and shot blasting is using regular steel shot. He said he heard one unsubstantiated story that a shop uses regular steel shot, which has the potential of becoming magnetized and remaining inside tight crevices before falling into the oil flow.
Lord of the Rings
An all-around machinist, gunsmith and welder, Tony Smith also works in fine detail by making one-of-a-kind titanium rings. He learned to work with the lightweight metal while building competitive bicycles, and now creates custom wedding bands and other jewelry with unique gems or engraving. Check out his Facebook page for more.
Certainly the rebuild of this Flathead was done right. The engine is out of a tough farm truck that served the same family since it rolled out of the showroom. Following a full frame-off restoration, it will be handed down to a high school graduate following her commencement.
“The owner wanted a the engine to be reliable with a little more punch,” adds Smith, noting it had been rebuilt several times in the past.”
No doubt the engine was quite tired. The valve springs registered only 30 pounds seat pressure. Other components that needed replacing included the pistons, bearings and valves. A slightly hotter camshaft from Edgy Speed Shop was also installed; otherwise, the engine went back together with a lot of attention focused on the tolerances and details.
Smith is currently working the restoration of a rare 16-cylinder Cadillac engine. EngineLabs will have an in-depth report on that unique powerplant in the near future.
Clockwise from top left: Edgy Speed Shop provided a new cam with a little more aggressive specs. Adjustable lifters were also installed. The original non-adjustable lifters meant valve clearance was adjusted by grinding the valve-stem caps. And a fresh set of Isky springs were installed.
The bottom end was buttoned up with a new oil pump and pickup. The oil pan required a little patching up, including a new dipstick tube mount that was welded in place, compared to the original one that was riveted and leaked.
And here’s the finished engine, ready for carburetor and ignition.
