Gurew

iTrader: (4)

hardened gears doesnt mean ****.. thats exactly it..the shaft is brittle compared to say the rew shaft, under stress the shaft shears...proof...how about seeing 3 hybrid engines with sheared rx8 shafts.

you wont find any factory documentation because thats a mazda "secret" use an rx8 shaft and by all means when it breaks...report back so i can say "ha ha"

the weight savings is on the inner side of the shaft so rotational mass is still near the same, the actual gains that people think they get is not worth the risk of the shaft shearing

just remember....the rew shafts go through a very secret heat treating process which allows the shaft to be rigid but also flexible enough so that it doesnt shear in half...the rx8 shaft literally is missing some key parts of the typical heat treating due to the fact it wasnt engineered to see the stress' the turbo engines see.

for reasons i dont want to say, this information was relayed to me by someone that gives seminars at mazda headquarters and owns a fairly successful rotary engine shop. also i have seen rx8 shafts in person that have sheared while being used in "hybrid" engines, 13bt and rew

jackhild59

iTrader: (7)

If I told you, I would have to kill you.

Regarding the broken shafts: Pictures, or it didn't happen.

Gurew

iTrader: (4)

think what you want lol....


ah well it blocks the link..pm me and ill send the link,





enjoy

glenrx7 = owner of azrotary rockets, very knowledgeThe rx8 is an na engine with a low combustion pressure putting less stress on the shaft. You increase combustion pressure and you increase forces on the shaft. So for the sake of argument lets jump into black and white for a second. Combustion pressure basically aquates to torque, if you increase it the tourque will increase increasing the force aplied to the rotor, bearing and shaft. So with boost you increase combustion pressure. So with out the turbo you have less force on the shaft even at 9k.......Not to mention the torque on a renisis is well we all know that ./


Now if the shaft is bent .006 it is out of :mazdaspec" by .0045.


The shaft being bent .006 at one point of the shaft would give you a diameter of .012 meaning the shaft is digging .006 all the way around pushing the rotor out of place destroying the bearing etc.ble guy that was trained by paul yaw of yawpower/injector dynamics

10thAEWHiteHeat

iTrader: (4)

hmm.. so this has not made my decision any easier. I am not sparing expenses on this project, so I wouldn't mind spending 200 on the Rx-8 shaft. But i don't "need" a new one. If someone can completely convince me that keeping my 115k 13b shaft is better than getting a new Rx-8 shaft then I will just pass it up. Gurew send me that link dude I am interested to see where you are coming from.

farberio

iTrader: (7)

^its not just buying the Eshaft, you will want to get the assembly balanced as well. So thats another $300 or so at least.

farberio

iTrader: (7)

I am usually with you. But this engine was not meant to last. It was meant for me to learn to tune on, and abuse the hell out of it as I learn to drive on the track.

Then again I put a small amount of miles on my car. So if an engine built without the latest and greatest components lasts 20k miles thats a good 10 years for me. Which really isn't that bad.

rotordad

It's amazing how it's a Mazda "secret" but you know! Doesn't seem all that secret now does it. Also as said earlier it's a little odd that Mazda would beef up the stationary gears & use multi window bearings (all improvements from the previous) just to use a inferior shaft. As far as documentation there may not be info released from Mazda, but a test on the RX8 shaft from an independent company showing it is inferior is possible. You say you have seen 3 sheared RX8 shafts, how many non RX8 shafts do you know of breaking? At what power levels did these shafts fail, a little more info on the build other then "hybrid with RX8 shaft" would be nice to include.

Gurew

iTrader: (4)

hey do yourself a favor give glen weaver a call at az rotary rockets..ask him his take on the rx8 shaft and also ask his experience in the rotary community..better yet..google his name or search for az rotary rockets on this forum


case close...dont use the rx8 shaft..they do use a "secret" method of heat treating...just as they use secrets for making apex and side seals....its no secret that there is a missing heat treatment part of the rx8 shaft....some people figure its due to keeping the costs down and not over engineering

all the stationary gear upgrades....is just to provide better oiling on the bearings and whatnot...that doesnt negate the fact that the shaft is more brittle and is lacking the "memory" as in when it deforms...it stays deformed causing premature bearing failure and eshaft failure both by bearing failure and shearing in some cases

rotordad

How about this you do yourself a favor & relax. He said she said is complete **** IMO. It doesn't matter to me who you suggest, if they can not provide proper documentation stating the limits then it's just speculation. Every man on this planet is capable of being wrong, no matter who they are & how much experience they have. So without proper testing results & just claims made because of a few broken ones means nothing. As I will not take anything away from Mr. Glen Weaver, I'm sure he is very versed on the rotary engine & could provide useful info. With that said I have no intentions in bothering the man, I made a clear cut suggestion about your open ended claims & you respond telling someone to talk to another person. So are you telling me you have no real experience with the RX8 shaft, just what others have maybe discussed with you? I'm wondering why it is that you seem to be getting so **** about this? BTW I'm glad you know the secret, must make you feel special.

j9fd3s

iTrader: (3)

i held glens first bad shaft in my hands, the failure was almost a galling, very weird, ive never seen anything like it.

they also do use a secret to make the apex seals, they have the germans do it.

IMO on the shafts. the shaft is a pretty durable part of the engine, ive got a forest of e shafts, but i have no good rotor housings.
if I was building the engine, i would measure the shafts i have, the chances of finding a good one are almost 100%.

then you can put the $200 towards things the engine actually NEEDS, like rotor housings

Gurew

iTrader: (4)

first...rotard...please learn to use proper grammer and spelling...you are old enough im sure to "KNOW" how to spell...nice edit btw but i caught it in the original email...


side note..glad to see someone else has seen the issues i have with the rx8 shaft, esp from the same person...

and another side note...im going to unsubscribe this thread due to the lack of rotary knowledge and ******* comments

nycgps

iTrader: (4)

Everybody can have their own opinion.

but there are also lots of other rotary experts who just give it a "OK" on the Rx-8 E-shaft. Its cheaper (obviously), it's slightly more balanced. have modification for better oiling. etc.

one more thing. was the engine balanced properly in the first place? cuz even stock engine parts is way out of balance at higher rpm. Im not saying Az rotary rocket does not know about balancing, but they probably got some "broken" engines from some dude and all he did was "use" rx-8 shaft, engine not balanced and broke, then told Az rotary rockets "his" own story.

hey u never know.

nycgps

iTrader: (4)

well, you have a point.

Im planning to keep my car forever, engine is just one thing, gonna get **** loads of new parts(already got like 1/4 of it, why 20 yr old parts cost more than my rx-8 parts? wtf?) + repaint the whole car inside out soon. so my way of doing things might be a tiny whinny bit different

D Walker

iTrader: (1)

And we will all miss your insight.
However, I am calling BS on the RX8 e-shaft failure until someone provides someproof other than 3 failed shafts out of God only knows how many.
I am also calling BS on the super secret process, until you give me something other than speculation and someone said, with the someone not being an engineer in powerplant developmentat Mazda.
Here is what _I_ know- Mazda intended for the RX8 to be a high-revving engine from the word go, hence the hardened stat gears. multi-window bearings and lighter e-shaft. They made some mistakes with the first engines in search of lower emissions, but those errors had to nothing to do with the e-shaft etc., in fact Mazdas orginal aim was to improve the durability of the engine, not "cheap out".

And FWIW- hardened gears DO MEAN something- perhaps you havent been around long enough to remember but you used to have to pay a pretty penny from MazdaComp to get a set, and sometimes you ahd to wait until they got around to making them. Now its easy, we just go right to the dealer and thats that. I also remember drilling my own multi-window bearings because I could not get them, and they werent cheap from MazdaComp either. Again, the fruitsof our labor are such that you, who apparently donot understnad what these pieces DO, can just go down to your local dealer and have as many as you can afford in a day or two.

Of course a man who sneers atothers lack of knowledge while choosing not ot provide proof of his own might not know as much as he cliams, but I am sure such is not the case here.

rotordad

So instead of providing more info on these motors in which the shaft failed you would rather try to insult my grammar in which you actually spelled incorretly! Good job there man.

papiogxl

iTrader: (6)

How is this flamefest still alive?

This is a topic that has been beat to death on this forum and others.

BTW, here is an FC shaft that failed (courtesy of Reted):


Any shaft is susceptible to faults, it is the simple nature of metal. Who's to say the shaft wasn't dropped during shipping/ prior to installation.

Liborek

Hey, don´t quit so quick

Why didn´t you mention how you were flamed on other forum by people who have successfully used RX-8 shaft in high power aplications?

rotordad

I always love how when some can not back up their claims they result into these tactics.
1st say everyone else has no knowledge of the subject
2nd refer you to someone else instead of providing the info asked for
3rd resort to try insulting you to distract you from the dicussion

Tofuman FC3S

iTrader: (1)

Someone with more money should put their ***** on the table and have a new FC and and RX8 shaft stresstested to the point of failure. The whole rotary community could know the truth for under 1000 bucks.

Riz.

JBarron

iTrader: (8)

That would be an important part of it, and there are also hardness tests and scales, Brinell and Rockwell come to mind. I think these kind of tests allow you to find the hardness of any individual point on the shaft, basically, and tell it's hardness, and probably the depth of the heat-treat, pretty precisely. That is the impression I get from my passing familiarity with it, anyway.

farberio

iTrader: (7)

If you dig deep you learn some cool things, for example the FC TII housings feature a harder steel liner and a layer of teflon for extra lubrication.

Also, just because Mazda intended to improve the durability of the engine doesn't mean they didn't try do do it at the lowest cost. Because the RX8 is not an engine with a lot of torque it doesn't see the same stresses that previous generation e-shafts see. That means that the RX-8 e-shaft could be cost reduced to handle less stress yet still function correctly in the renesis application. I am not saying this to imply that the RX-8 eshaft is indeed weaker, its more food for thought.

rotordad

It's pretty damn simple until there are test that show that they are in fact weaker, then it's just talk. As to the shafts that were broken, what were the circumstances in which they failed?

farberio

iTrader: (7)

Likewise, until there are tests to show that they are in fact equally as strong then its just talk.

nycgps

iTrader: (4)

the thing is that there are quite a lot of people who turbo'ed their Rx-8 with 350rwhp , they never had issue with the e-shaft snap in 1/2.

j9fd3s

iTrader: (3)

that one dies from an oiling/bearing problem. ANY shaft will break if you lock the engine up @100mph...