Aluminum side housings
 

im curious if anyone has used these side housings they are made of aluminum instead of iron they supposidly take more wear i imagine that they disipate heat better than the iron ones as well not to mention the weight reduction the thing that i cant figure out is if they will take the abuse that the iron ones that will? any one have experience with these or any info?

hmm ^ that is pretty crazy. i think mazda is trying aluminum sides on the new 16x engine or some renesis prototypes or soemthing. but i didn't know racing beat made them..

edit: 1.4k - 1.7k each? wow:scared:

sorry about the last post i had to edit it because i forgot to post the pic.

Given the price (around $5k for all three) I think they're not suitable for a street car. I'd think the main advantage would be weight savings, but you can save the same amount of weight elsewhere for a lot less.

It says somewher on RB's site that the aluminum housings are for P.Port engines only. If you need sideports, pick up the die grinder and go :(

Downing used to run the Aluminum housings that Mazda made originally. But they were unable to run the front housing in Aluminum as the front stationary load would crack and break free. So they always ran a steel front housing.
The RB ones from what Rick was telling my have a somewhat refined casting in the area where the front stationary mounts so they are not as weak. But IIRC the people running them didnt want to risk it so there was little use of the front housing.
You used to be able to get them cast the same as the original 74-75 housings with ports in them. But they were being used only on the GT motors, and stopped producing the side port variety because of lack of demand IIRC.

There was some discussion on this topic a while ago. Apparently these housings are plasma spray coated to increase hardness where it counts. I don't know much about material science, so I can't really comment on that. As far as thermodynamics go, the aluminum will conduct heat out of the expansion zone much more rapidly than iron. I am assuming the coating mitigates this to some degree, but I would bet there is still more heat loss than with the irons. Of course, all rotor housings are aluminum with some sort of coating along the inner surface (anyone know what this is, I know aluminum is often doped with silica for hardness, is that what it is?). I believe Mazda originally ended up making the rotor housing out of aluminum so the clearance between the rotor apex's and the housing would not get smaller as the two dissimilar metals went through there thermal expansion. Weight savings was a byproduct of this decision. Slightly less expansion energy (lost through thermal conductivity) would be a slight disadvantage to aluminum over steel. That’s part of the reason why rotaries have such poor thermal efficiency (their high potential power density more than makes up for this as any rotary enthusiast will tell you)

I also noticed that Mazdatrix sells an "Ultra-light Rotor Assembly" which can be found here: http://www.mazdatrix.com/engpartrace.htm

As you can see, the rotors in this kit are aluminum. This will definitely decrease rotational inertia, but I think there rotors also allow you to rev much higher. This is because there is less mass at the perihedron of the orbit pulling itself outward due to its own inertia. Basically, you can spin them faster without them stretching out from centrifugal forces. Steel has less malleability than aluminum, but the aluminum will have less force pulling it stretched (because of the lower density->mass->force). Many people on these forums say that they have not heard of any older 13bs revving over 9,000RPM and I think the RX-8 goes to 10,000RPM right? (Does anyone know why?). So I am assuming with the aluminum rotors you would be able to rev higher than an RX-8. Can anyone comment on how much higher? With the Mazdatrix kit you get 2 rotors, the rotor gears, and the counterweights for around $2,250.00, but increasing redline to 12,000RPM (figure just for arguments sake) might be worth it. The induction system is designed to still make pretty good volumetric efficiency that high up, so I would think you could greatly increase average torque in general by doing this.

Those mazdatrix rotors are not aluminum, they are stock rotors that have material removed from the sides by a CNC machine.

I'm sorry, I was not clear. The side housings I am refering to are the Aluminum Racing Beat housings...I just saw them on sale on the Mazdatrix site. I was not commenting on any side housings that Mazdatrix fabricates in house.