The top ring is 1.1mm and is plasma chrome coated for low friction, long life and heat resistance.The 1.2mm thick ductile iron second ring has a hooked face Napier profile. Napier rings break in quickly and give better oil control at high rpm and are really low friction.
The oil rings are narrow profile and low tension. There are two scraper rings on either side of a waffle-like separator. The separator gives space for the oil to drain to the interior of the piston via holes in the oil ring groove. This helps keep the piston pin lubricated
The rod is first machined to shape from a rough cut piece of billet then solution heat treated. This heat treating greatly improves the mechanical properties such as tensile strength of 4340 steel. Solution heat treating makes the alloy homogeneous where all of the atoms in the material effectively become a solid solution during the treatment causing the alloying elements to be evenly distributed around the part.
After heat treatment, the rod is shotpeened which can improve fatigue strength by over 100%. The shotpeening is what gives the rod’s surface its pebbly texture.
The small end of the rod is bronze bushed and has two small oiling holes on the bottom of the pin hole on either side of the rod, low in the sides of the beam. This is preferable to the typical one larger hole at the top of the rod as this is the highest stressed area of the rod’s small end.
The K1 Rods use strong 7/16″ ARP 2000 bolts. These bolts have a tensile strength of 220,000 psi which is important when you consider that the rod bolts are the weakest and most failure prone part of the rod.
The XP bearing’s P-max Black material is a tri-metal bearing with steel, a very high capacity copper based intermediate layer and a softer lead-based overlay that contains 5% copper and undergoes a proprietary hardening process for industry leading load capacity.
We have yet to have a bearing failure with any King Bearing equipped motor and all of the bearings we have inspected look almost new, even after an entire season of racing!
We will be replacing the stock oil pump with this heavy duty part by Ford Motorsports. The Ford Motorsports pump uses precision ground billet steel gears that are much tougher than stock. This way we can be assured that we can rev the engine higher than 8K if needed and that something like a missed shift won’t nuke the pump and scatter the engine.