Extreme Engine Tech: Building the Ultimate K24 Part 2 The Bottom End!

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The stock K24 crank is a sturdy forged fully counterweighted part.  No need to change that.  We simply deburred it and had it balanced.

The stock crank trigger wheel bolts on solidly.  It is not prone to falling off like the pressed in part on the LS engine.  We don’t anticipate problems here at all.

 

For connecting rods we decided to use parts from K1 Technologies. K1 rods are machined from a forged 4340 steel billet.  4340 is a heat treatable alloy steel similar to chrome molly, having nickel, chromium and molybdenum as alloying agents to give it roughly double the strength of regular steel with a higher nickel content making it stronger and tougher with a higher impact resistance.  These properties make 4340 an ideal alloy for connecting rods. The rod is first machined to shape 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 making the alloying elements evenly distributed around the part.

The K1 rods small end is bronze bushed and the rod machined so the sizing can be held to plus or minus 0.0001 and the weight within one gram per end.  Those are exceedingly tight tolerances and important for noise control. The slightest excessive clearance on the small end makes an audible knocking sound.  After treatment the rod is shotpeened which can improve fatigue strength by over 100%. Another cool feature is the use of high strength 200,000 psi ARP 2000 rod bolts.  These premium bolts have asymmetrical threads for more thrust engagement for better torque consistency.
For rod bearings we chose ACL Race bearings. The bearings run very tight crush clearances to reduce the chances of spinning.

We also used King XP bearings for the main bearings. The XP bearing’s pMax-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. In addition, the King mains have elliptical oil holes, undercut oil grooves for maximum bearing area, a very tight crush for optimal heat transfer and solid retention and an eccentric ID to help form and maintain a hydrodynamic oil film easier.

 

1 comment

  1. Cool to see you guys using the newer k24 blocks, wished you used the head too because I wanted to see what works. I’m building a k24z3 and saw that you cut off the balance shafts, by retaining the stock oil pump system means I can still use the bottom location oil filter correct?

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