Project Do It All S13, Assembling the Bulletproof SR20DET Bottom End!

The Boostline rods come with silicon bronze bushing in the small end.  The rods have an aggressive shotpeened finish to improve fatigue strength.  Although the rods come balanced to within 2 grams, we precision balanced the rods to less than one gram. We also Cryo and WPC treated the rods and bolts.

JE Pistons custom-made some beautiful pistons for our stroker motor using a lot of the standard features of their Ulta line.  They started with a near-net shape Ultra blank for optimal grain flow for the best strength.

Once our combustion chamber volume was determined, the piston dish was modified so we could have a conservative 9:1 compression ratio despite the increased volume caused by the stroker crank.  We wanted to gain dish volume without affecting the piston’s quench band so this was taken into mind when designing the crown shape. The crown was coated with JE’s Ultra gold thermal barrier coating.

JE’s FSR asymmetrical forging was used, on the thrust side of the piston, the skirt is wider to provide more surface are and support for improved wear and bore stability.

On the less loaded side of the piston, the skirt is minimized for less weight and friction. The skirts are coated with JE’s Perfect Skirt coating.  The coating reduces friction and wear, especially during start-up. During break-in, Perfect Skirt coating burnishes in quickly so the piston matches the bore perfectly.


  1. What are the boundary conditions for the FEA images? Something looks a little strange in how forces are applied to the little and big end… Are they not treating it as a pinned connection with bearing loads for the application of the loads?

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