We are using the Built 2 Apex oil pan.
This pan has a very thick flange that will also help stiffen the block. Inside are five trap doors that keep the oil close to the pickup tube to prevent oil starvation during high-G corners. The 13B is not prone to oil starvation issues, but these baffles will further improve the reliability and increase the margin under the most extreme conditions.
After installing studs for the oil pan, we bolted the oil pan down and installed the engine mounts. 1993 RX-7s are supposed to have an aluminum engine mount on the driver’s side; but this car had the 1994+ iron driver’s side engine mount. Interestingly, this car also has the 1994+ rear subframe reinforcement braces.
The Built 2 Apex oil pan looks quite good, especially after being vapor blasted to match the rest of the engine.
With everything torqued down, that means our 13B REW is now fully assembled!
Two years of delays and machining has resulted in this beauty. The vapor blasted aluminum irons and front cover are a shiny contrast to the DupliColor Metalcast Blue irons. When I first saw this color combination, I just had to build my engine to look like this.
We were very happy with how the engine turned out, the beauty of the outside of the engine matches the inside. We WPC and CTP Cryogenically treated everything from the 0.638lb lighter rotors to the I-Rotary Apex Seals, Atkins Rotary Solid Corner Seals, side seals, e-shaft, Mazda competition bearings, irons and housings. The fully cryo treated engine should be far stronger and molecularly stable than the non-heat treated factory components. Our engine was braced with 4 more dowels and Turblown studs to greatly increase the rigidity of the block. We also increased the oil pressure of the system with modified oil pressure regulators and Mazda competition oil jet kit.
All of this improves the strength and reliability of our engine at 9,500rpm+ and when making big power. Where power is really made is in the porting. Abel Ibarra worked his magic taking his decades of porting experience to give our engine his special turbo-focused and relatively small bridgeports along with a semi peripheral port designed to minimize overlap, but create a broad powerband all the way to redline. Needless to say, we can’t wait to get this installed and running to see what all of this work ends up doing.
We couldn’t help but weigh the tiny 1.3L keg. The entire “short block” weighed in at 189.2lbs with no accessories. Keeping in mind we removed 1.28lbs from the rotors, and even more weight from the counterweights, which would put this setup to over 190lbs.
It is so amazing that this little engine, with the modifications that we have done to reinforce it, is capable of making 1,000hp (according to Abel) with a properly sized turbo. That’s less than half the weight of a 5.0L Ford Coyote V8 which weighs 430lbs with no accessories and includes a 15lb plastic manifold and (5lb?) throttlebody.
Stay tuned where we install the drivetrain into the FD!
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.