Our 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.
In 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.
An 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.
With our housings and rotors on the bench, we were ready to start assembling our rotors.
The first step was to install the oil control rings.
9 comments
Is the blurred out images of the port, really NSFW, or just a proprietary secret?
Otherwise, love the assembly porn!
It’s a bridgeport with a semi-peripheral port.
Lol I figured it must be some JDM mosaic NSFW material too.
Great documentation. Can’t wait to see further progress.
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?
Dylan,
I have had experience with both. You only crack corner seals if you have an incorrect tuneup. Oem for everything and stay away from Atkins. Their coolant jackets and apex seal springs are not oem and will cause problems in your build. See my thread on rx7 club titled Warped Apex Seal Teardown.
I think Able is one of the best engine builders and I would stick to his advice.
Hi Mike,
Why does Atkins recommend not using their solid corner seals with lapped side housings?
Thanks
Atkins does not recommend lapped side housings in general. From their website:
Side housings have a nitrided surface, which is a heat treating process that diffuses nitrogen into the surface of a metal to create a case hardened surface.
When you lap a side housing you remove this nitrided surface.
We do not offer this service nor do we condone it.
When this nitrided surface is removed excessive wear can occur when using any seal that comes into contact with the side housing, including Mazda corner seals and Atkins Solid Corner Seals.
It can also cause excessive wear to the side seals and oil rings when they come into contact with raw side housings with no nitrided surface.
According to Abel, the Atkins solid corner seals will improve compression over stock, and stock corner seals start to see limitations at certain power levels where solid corner seals become far more necessary and beneficial.