I have a collection of pistons and a rotor from an early 1.0L (10A?) on display on my workbench, just to create discussion and curiosity. The rotor appears to be made out of cast iron and is quite heavy. I was wondering what material the rotors are made out of in the new Renesis engine. Are they aluminum, still cast iron or... ?

1.3L

 

Still cast iron, but a little thinner.

S

 

It would be nice if they could drop weight significantly. The 10A rotor you have is actually lighter than the renesis rotor which is slightly lighter than the 3rd gen RX7's. There were some rotors that we used to call 'G' rotors that came in the 13G engine (Competition 3 rotor) that were lighter than renesis but are now completely unavailable which were not as light as those found in the R26B. Those appeared to be of a more exotic material while the others seemed to be cast iron with thinner and thinner webbing in areas to reduce weight.

Sorry for rambling.

Paul.

 

I never understood. What is the issue with casting the rotors in aluminum? is there some kind of detriment to the rotor being too soft, or is this a cost issue, etc...

 

Just the same casting technique they never changed, it has worked before it'll work now. Although improvements have been made, but I agree that the use of lighter weight alloys/metals would be beneficial. Most likely in race applications, higher RPM, less stress on E-shaft. I made a post about it in the "advanced renesis tech" thread.

Does anyone know if the use of lighter/different alloys for the rotary engine can change the resonance frequency? So it can be revved higher than ~13k.
________
Nonude teen models

 

Aluminum isn't as strong as steel or cast iron. There are people that have dented and cracked rotor faces. Aluminum couldn't take that much abuse.

Cost is always an issue.

 

Why do you keep mentioning a cap at 13K rpm? Every thread. Where does this number come from? It doesn't exist! What makes you think it will go that high? It depends on how it's built. You might blow up a stock one at 10K and a built one might have a reliable shift point at 13,500 rpm. On the other hand you might accidentally rev a stock one up that high under little to no load and have nothing happen to it. How long it is held at high rpms and how it is treated up there has a greater affect on what rpm it will die at than anything. There is no mythical 13K rpm cap.