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DiLL (2/2/2022)
Joe, would you mind sharing the specs on the forged pistons you ordered from JE? I'm in the process of trying to get my pistons ordered and would like a reference. If for competitive reasons you're unable to I understand. thanks! 55blacktie (2/2/2022)
Joe, does that include forged flat-tops/w no valve reliefs and metric rings for EBU and C2 rods? Thanks. Because there were some questions regarding piston ordering asked in a different and somewhat unrelated thread, I have started this post specific to ‘Custom Pistons’. When ordering custom pistons, the piston rings are the first consideration and are ordered prior to ordering the pistons. Piston rings are not available as an ‘off the shelf’ item for every possible bore size so the bore size must be determined first. Depending upon the availability, it may be necessary to juggle the bore size in order to get the ring width sizes you are looking for. Because of the many small bore metric sized pistons that are available, there are a number of cylinder bore size options but these may not fall in the normal 0.020, 0.030, 0.040” sizes that are typical to the American engines. In some cases, the final bore size may fall into ranges between those numbers. When the rings are ordered, you will need the bore size, ring thickness, and radial depth numbers for those rings so that the pistons can be machined specifically for those rings. A word of caution about ring thickness. As the rings get thinner, the cylinder wall finish gets more critical.
  Lorena, Texas (South of Waco)
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Group: Administrators
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Another point to consider when custom ordering pistons are the wrist pin locks. The Ford Y had full floating wrist pins as delivered from the factory and as such, required wrist pin locks. The FE and MEL engines also used full floating wrist pins. The SBF (289/302/351W,C,M) and 385 series engines (429/460) used a press fit on the rods for the wrist pins and did not require locks on the OEM pistons. Full floating is recommended in performance applications as any friction in the wrist pin area is distributed to additional points thus reducing overall friction. Many of the factory wrist pin retaining clips for the Y were round wire. The replacement cast pistons would have either round wire or square wire clips. Keep in mind that whatever wrist pin locking clip the pistons are machined for is the clip or lock that must be used as they are not interchangeable. The grooves within the wrist pin holes are specific to the lock that’s being used. With any locks that have an opening such as most round, square wire, and Tru-Arc locks, then install those with the opening vertical to the piston movement. The aftermarket pistons use a variety of designs for the wrist pin retaining clips for the full floated pistons. They range from Tru-Arcs, single Spirolox (aka Spiro Locks), double Spirolox, and round wire clips. The Spirolox clips are typically easy to install but can at times be a challenge to remove. Tru-Arc locks do require a good pair of lock ring pliers in which to install/remove these locks. With the Tru-Arc locks, you’ll find a sharp outer edge and a rounded edge on the other side. Install these with the sharp edge facing to the outside of the piston. The 0.063” and larger round wire clips are much heavier in design than what Ford originally used in the Ford Y and while they can be hard on the thumbs when installing, they are relatively easy to remove as long as the piston has the notch in the wrist pin groove to allow a small pick or screwdriver to catch the underside of the round wire lock and simply pry it out. With these larger diameter round wire clips, it’s recommended that the wrist pin ends be chamfered on their outside edge to help keep the locks securely seated in their grooves. With all that being said, my own preference is the 0.073” round wire clips when I have a choice as I have the specific tools to aid with their installation. Those tools beat a lot of wear and tear on the thumbs when installing. When ordering custom pistons, just ask as to what the wrist pin lock options are as not all piston manufacturers offer the same options. Here are pics representing just a sample of the various wrist pin retaining clips that are available.
        
Lorena, Texas (South of Waco)
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