Next, we installed the Turblown Engineering 13B RX-7 Rotary Engine Studs. These studs are another key component for creating a rigid and stiff engine block by providing a more linear, precise, and even torque to the engine compared to the stock tension bolts.
OEM bolts allow the engine to expand several thousands, as measured with a strain gauge on an engine dyno. This expansion can damage the engine internals. The Turblown studs are precision ground from aircraft quality forged steel, heat treated, and are made with hot rolled threads. The studs reduce this engine expansion and movement, which is a must for high-powered rotary builds like ours.
The Turblown studs can be torqued down much higher than the 23-29lb-ft range for the factory tension bolts. Turblown lists a maximum torque of 77lb-ft for their studs, but warns that the irons might break near this limit.
We lubed up the WPC Treated rear stationary gear bearing and installed it into the rear iron.
Then we installed the rear seal.
We flipped the engine over to start assembling the oiling system.
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.