Project FD RX7 Restomod: Part 19 – Assembling the 13B REW

13B REW Semi Peripheral Port Bridge Port Lightened Rotors WPC Treated CTP Cryo Treated Rotors, Eshaft, Seals, Housings, and IronsOur 13B REW is finally ready for assembly, now that our rotors are lightened, irons are bridge ported and semi peripheral ported, and we WPC Treated and CTP Cryo treated pretty much everything.

After nearly 2 years from the fire that started us down the path of tearing down and building a brand-new Mazda crate engine that had 2,000 miles on it, into one of the most highly-modified 13B REW engines (with stock irons) on the planet, we were ecstatic to finally see everything come together.

13B Rotary RX-7 lightened Rotors, WPC and CTP Cryogenics treated rotors, I-Rotary Apex seals and Atkins Rotary corner sealsIn Part 12, we removed 0.638lbs from each rotor prior to WPC Treatment and CTP Cryogenically treating the rotors, apex, side, and corner seals.  We are using the I-Rotary 2mm Metallic Apex Seals, designed by Dr. Iannetti.  This 2-piece design was the culmination of 22 years of testing and development to create an apex seal with the same sealing performance as the stock Mazda seal, ensuring high compression, maintaining excellent sealing, toughness, and durability in extreme temperature, loads, lean conditions, and detonation, and have low friction and wear while being gentle to the rotor housing chrome surface.  Our engine builder Abel Ibarra recommends I-rotary seals and Atkins Rotary Solid Corner Seals and has been using this combination successfully for many years.

13B Rotary Engine Mazda Competition Rotor Bearing WPC TreatedAn important upgrade for engines revving above 8,500rpm and in high boost applications is to use the Mazda Race (Competition) Rotor bearing (PN: 4801-11-111).  This bearing has a 1mm (0.04”) deeper oil groove and provides 0.012mm (.0005”) more clearance than stock bearings.  We WPC treated the rotor and stationary bearings based on our experience and success with treating crank and rod bearings in piston engines.

13B Rotary Housings and Lightened RotorsWith our housings and rotors on the bench, we were ready to start assembling our rotors.

FD RX-7 13B REW Lightened Rotors oil control ring installedThe first step was to install the oil control rings.


  1. Is the blurred out images of the port, really NSFW, or just a proprietary secret?

    Otherwise, love the assembly porn!

    1. Lol I figured it must be some JDM mosaic NSFW material too.

      Great documentation. Can’t wait to see further progress.

  2. When researching components for my RX-8 engine rebuild a lot of people recommended avoiding Atkins solid corner seals because all else being equal, you’ll see lower compression compared to an OEM corner seal. In this case is the added strength a worthy tradeoff for the compression because you can add a bit more boost to make up for it or are you just not seeing a compression loss on the RX-7 version of the seal?

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