Project 350Z- Building a New Engine Part 2


With the crank installed it is spun by hand as a final check for proper clearances and tightness. If the crank is tight or has tight spots the root cause must be found.  The crank straightness must be rechecked or the block may need to be align honed.  Most Nissan blocks do not require an align honing.
The King XP rod bearings are installed into the rods after the rod’s big end and bearing shell backs are thoroughly cleaned.  The K1 rods are much stronger than stock which are marginal at around 7500 rpm.  The rod bolts are the weakest point of the stock rods.  Changing the rod bolts to later model Rev Up parts can be a low buck upgrade that will get you a few hundred rpm but having way stronger rods is even better.
With the bearings in place and the rod bearing caps installed, the bearing bore can be accurately measured. The bearing bore diameter is subtracted from the crank journal diameter to calculate the clearance. King XP bearings are tri metal in construction meaning that they have a steel back for high load capacity, an intermediate layer made of a copper matrix infused with a lead-tin alloy, the lead acts like a lubricant while the copper gives hardness and load capacity. The tin helps give the lead some hardness also to increase load capacity. King XP bearings have a higher copper and tin content than usual to help improve the load bearing capacity.  A thin layer of nickel plating is on top of the intermediate layer which keeps the tin in it from migrating into the the softer overlay. This is because tin can make the overlay corrode.  The overlay’s job is to provide embeddabilty. This helps reduce damage by contaminants in the oil by allowing them to embed into the overlay instead of being ground into the crank. The overlay on the King XP bearing’s pMax black overlay has a higher copper content and their proprietary nano hardened thin top section to give an even greater boost in load bearing and capacity and fatigue strength.
The bearing bores are measured in three places to confirm roundness and the correct diameter.
The JE forged pistons are now hung on the rods by pushing the lubricated pins through the pin boss and the small end bore of the rods. When the pin is in place the piston pin retainers snapped into place.
The piston rings are spiraled onto the ring grooves in the pistons and the gaps staggered.

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