RX8 E-shaft vs 13B-RE/REW shaft

glenrx7 · 06-09-2009, 10:25 AM

Well first I have been building rotary engines for a long time....

I built a 13b rew for a customer of ours at AZRR, his original had spun a bearing and the shaft was toast. So after some long nights talking to Maada Na engineers it looks like the 8 shaft was built in the same way as the third gen shaft. I had finite element data, mazda engineering data basically telling me that the shaft was built just as strong as the third gen..........

Dyno day come and we are hitting some pretty bad ass numbers right off the bat about 420 with 300+ foot pound with low boost about 13psi, out of the blue we loose 20% across the board. So I go to work checking spark and just about every thing, things get worse as we drive it then I start feeling it in the clutch bam it stops running. Take it apart and we have a bent shaft about .006 of an inch out at the front. This caused the engine to eat it self alive.

So, I went to the long task of figuring out why...so far what I can come up with, is there is an important tempering process that was not performed on these shafts for what I think is cost. the tempering alows the metal to deform and spring back this did not, it deformed and stayed there.

What is its limits, I am not sure but putting any kinda stress on these would scare me. So I will never build a turbo engine with this shaft again.

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06-09-2009, 10:25 AM	#12
glenrx7 Rotary Fanatic Join Date: Feb 2008 Location: Arizona Posts: 199 Rep Power: 18	Well first I have been building rotary engines for a long time.... I built a 13b rew for a customer of ours at AZRR, his original had spun a bearing and the shaft was toast. So after some long nights talking to Maada Na engineers it looks like the 8 shaft was built in the same way as the third gen shaft. I had finite element data, mazda engineering data basically telling me that the shaft was built just as strong as the third gen.......... Dyno day come and we are hitting some pretty bad ass numbers right off the bat about 420 with 300+ foot pound with low boost about 13psi, out of the blue we loose 20% across the board. So I go to work checking spark and just about every thing, things get worse as we drive it then I start feeling it in the clutch bam it stops running. Take it apart and we have a bent shaft about .006 of an inch out at the front. This caused the engine to eat it self alive. So, I went to the long task of figuring out why...so far what I can come up with, is there is an important tempering process that was not performed on these shafts for what I think is cost. the tempering alows the metal to deform and spring back this did not, it deformed and stayed there. What is its limits, I am not sure but putting any kinda stress on these would scare me. So I will never build a turbo engine with this shaft again.