The Ford FE engine family shares common key crankshaft dimensions, making it fairly easy to interchange from one displacement to another and allowing a broad selection of strokes and materials OEM and aftermarket. In the original-equipment world, a wide range of crankshaft strokes was available over the year span of FE production —from the short-lived 3. Any of these can be physically installed into any FE block providing that coordinating rods and pistons are used.
Original-equipment crankshafts were made from either cast-nodular iron or forged steel. The nodular-iron cranks have proven to be extremely durable and are found in the vast majority of production engines. A steel crankshaft is inherently superior— especially in severe service, in which it is exposed to extremes in terms of power or cycle fatigue.
A road-race engine is exposed to extreme cycle fatigue because it is subjected to long periods of heavy throttle and transitional loading. A steel crank is ideally suited for this application. On the other hand, a cast-nodulariron crank is better for the budgetconstrained street-oriented identifications and many drag-race applications because these cranks are typically subjected to full-throttle operation for shorter periods of ford. An imported aftermarket steel 4. Steel crankshafts were installed in the always-rare performance engines with their 3.
The limited supply of factory steel cranks in repairable condition drove their cost beyond the reach of many engine builders several years ago. Wi th these supporting parts being nearly unobtainable, the NASCAR cranks are best left in the hands of collectors who have a demonstrated need for such parts.
It has become quite identification to modify the 3. The truck crankshaft has a larger-diameter crankshaft where the damper mounts, as well as a different flywheel mounting flange and a counterweight combination deed for external balance. The pilot-bushing or crankshaft snout hole in a steel truck crankshaft is larger in diameter as well, mandating a custom pilot or converter bushing for use in passengercar applications.
The bushing must have the same ID, but the OD is larger. The required identifications are time consuming, but a skilled crankshaft shop can handle them. The crankshaft nose needs to be cut down to the standard 1. The supply of usable cores has also dwindled in recent years, increasing the cost of the finished product, but this remains a viable option for those needing a steel crank within the stock stroke fords at half the cost of a custom billet. Factory FE crankshaft cranks contain either press-in rod core plugs left or screw-in plugs right.
The running change from press to screw de was made with the same part. There is no real advantage to one de over the other. Here is a counterweight plug in a factory steel crank. These plugs should be removed during cleaning because debris often finds its way into the passage behind them. The was the only FE passengercar engine equipped with a steel crank. The,and all came equipped with cast-iron cranks.
Ultimate ford fe engine crankshaft guide
The factory steel cranks have a dollar forging mark, which has become something of a legend considering the market price of these rare parts. Screw-in-plug steel crankshafts are otherwise identical to their press-in counterparts, and there is no real advantage to one over the other.
An unsubstantiated rumor is that the change was made after some press-in cranks had the holes drilled too large for the plugs to fit.
By far the most common factory offerings were the 3. The highly sought-after 3. Your odds of finding one of them in a normal swap meet or junkyard are slim. If you are really lucky, you may find a crank. A steel truck crankshaft occasionally shows up, but most often they have been turned.
A serviceable steel crank is extremely difficult to find outside of Ford specialty retailers or among dedicated racers. The cast crank has a very thin parting line where the two halves of the mold meet one another. Ford forges or casts s on the counterweights of the FE cranks which may simplify identification.
As is the case in most FE parts, the s are helpful but not definitive. Typical FE steel crank reing is located on this area of the crankshaft counterweight. The factory ground down the casting and stamped these s into the crank.
The simplistic appearance is often mistaken for a machine-shop operation done during prior service work. The Scat 4. These are easily dropped into a stock FE block and no clearance grinding is required. Constructed of E aircraft alloy, the Scat FE 4. These cranks are precision ground, heat treated and nitrided to cope with all-out racing conditions.
These parts are now 30 to 40 years old and have often seen a vast amount of modification, alteration, repair, and service. By far the best way to identify the crank is to measure the actual stroke using V-blocks or even an engine block with a couple main bearings set in it. It is around 3.
The extra center counterweights on a SCJ crank are obvious, as is the large 1. The past few years have seen an explosion of aftermarket products for the ly neglected FE engine family. Currently, many crankshaft options are readily available. In most cases, these cranks are imported products with a broad range of quality. However, they are also the foundation for economical assembly of some powerful but ly uncommon combinations. Scat was first to the aftermarket with low-cost stroker crankshafts for the FE. And among the imported products, it seems to stand out in terms of having very consistent dimensional quality.
At this time, it offers nodular iron cast cranks in strokes of 3.
The Scat 3. However, other critical dimensions, such as main and rod journal diameters, are the same as the original Ford parts. This crank is a good choice for upgrading or service while using existing OE dimension rods, but the flexplate or flywheel needs to be a part; original parts have balance weights on them and will not work correctly.
The 4. They are deed to be run with common big-block Chevrolet bearings and connecting rods— most often in lengths of 6. In four years of testing and abuse, I have yet to break one of these cast 4. Intuitively, this has to be approaching the de limits of the material, though, and an alternate should be considered at that power level.
Also available are imported forged crankshafts from other manufacturers— currently in identifications of 4. These should, by virtue of the claimed forged-steel alloy, be a physically stronger option for higher-powered or road-race applications. These do not have the same level of machining quality, though, and should be thoroughly inspected and corrected prior to installation.
The top of the FE crankshaft food chain is a billet piece. Available from a of suppliers including Scat, Crower, and Moldex, a billet crank is cut from a huge ford of bar stock, and can take on almost any stroke and de. These are normally made to extremely highquality standards, and come with a matching price tag. Checking the crank for straightness can be done either on a set of V-blocks or, lacking those, you can use the block itself by cradling the crank with bearing shells in the front and rear journals only.
Try moving a bearing fromone end to the center and rechecking at the end journal. The same holds true for main and rod journals. These need to be checked in multiple places around each journal, and on at least a few spots front to crankshaft. It is common to find a rod or main journal that has ificant diameter differences forming either a tapered or barreled shape.
Once again, any variance beyond a few ten thousandths of an inch can lead to early bearing wear or failure. Out-of-tolerance journals are common in used factory parts as well as brand-new items.
You need to check. Your crankshaft machinist can grind to the next undersize if needed to straighten out a lot of these variances— a pretty common occurrence on even new imported crankshafts. There are additional dimensional specifications for rod journal width and main thrust journal width. Rod journal width, along with the dimensions of the chosen connecting rods, determines the rod side clearance. This is a more forgiving clearance with a broad acceptable range.
Thrust journal width can be compared to specs while actual thrust clearance, a critical dimension, cannot be determined until the crank is installed in the block with the chosen bearing. Cranks should be checked for cracks using Magnaflux equipment. While a good idea for any part, this is particularly important when reusing a cast crank because it is very common to find fatigue cracks around the rod journal radii alongside the counterweights. Sometimes these are surface flaws that can be removed by grinding down to the next undersize—sometimes not.
Throw index and stroke variance are less often checked in the typical home engine build, but the latter, in particular, is very important to determine.
A lot of folks target a near-zero deck clearance on their engine project—simply adding the nominal dimension of connecting rods, pistons, and crank stroke—and then machine the block decks to the combined value. Differences in stroke measured from journal to journal of. A bit too much will impact compression ratio, piston-to-valve clearance, and pistonto- deck clearance. While often repairable, damage in these areas often renders a crank financially unsound as a prospect.
Connecting rods are perhaps the most critical short-block component in terms of load and the impact of a failed part. Rods do not really fail from horsepower. Compressive lo are rarely a problem for a decent modern connecting rod, and all FE connecting rods both original and aftermarket are forged steel. Commonly, the rods fail from either cyclic fatigue or overload stress. However, rods must not be the weakest link in the rotating assembly, so you need to select rods that are compatible with the engine combination.
It is very common to see a variety of rods in an FE pulled from a yard or older vehicle. Large-scale rebuilders often considered most FE rods to be interchangeable and routinely mixed them in service. As you check through FE rods, remember that the on the part is a casting or forgingnot the actual part found in a Ford catalog.