Pistons, Rods, Harmonic Balancer Monday, September 14, 2009 I’m pretty excited about the pistons I’m using. I came across them totally by accident at a time when I was looking into either building a stroker motor or keeping the stock stroke. At the time I was also interested in maximizing rod ratio. The pistons were on <a href="http://www.flyinmiata.com/dealoftheday/index.php">Deal of the Day</a> section of the <a href="http://www.flyinmiata.com">Flyin’ Miata</a> website. I actually called FM and spoke to Jeremy about them months ago. Since then, the pistons had been taken off of their site, so I considered them sold. Fast forward to a couple of weeks ago, shortly after my engine toasted. My car was at Apex Automotive Engineering and I was talking to Les about a plan. Les had a ’99 head that he had Dana @ Import Machine prepare a few years back, and offered to sell it to me. I agreed to buy the head and then mentioned the pistons I saw on the FM site. Les suggested I call and ask if the pistons were still available. I did, and they were. I am told that these pistons were one-offs for a test that never happened. The pistons are “stroker” pistons designed to work with FM’s stroker rods but a stock crank. The result is a bump in rod ratio, which favors high revving engines. Between the ready-made head from Import Machine and FM pistons & rods, I figured I would add the ATI harmonic balancer and call it a day. As it turns out, I have probably read about these pistons before, and you may have too. I was paging through Keith Tanner’s <a href="http://www.targamiata.com">Targa Miata </a>build a few days ago and saw a post where he installed a set of pistons that ended up standing 2mm proud of the block. Bingo! These must be them. Pistons are 85mm, 11.5:1, and allow for an additional 6mm of rod length. <a href="perma://BLPageReference/87494254-75E2-4CE4-A4C0-92E25E5DE949">Pictures are here.</a>