jeremy

iTrader: (1)

whats an e-shaft?

scathcart

Damn, I hate soulding [sp.] like a 12 year old
I think believe that you are the one apperaing young with your inability to admit ones ignorance, and display extreme stubborness.

Proof? Ok. Then explain to me first, why does the E-Shaft flex?!
I already did. Offset mass on a reciprocating assembly creates force. All forces on an object causes flex. It is called centrifugal force.
The greater the revolutionary velocity, the greater the force, and thus the greater the flex. Do you really want equations to back this, b/c I can provide this.

But again, I already stated this. Can you explain why it doesn't flex? So far all you ahve said in this argument is that "No, it doesn't flex" without ever providing a reason for why it doesn't.

I have proven my reasoning. You have not.

You're in over your head. I suggest you get out before you are entirely buried.

Does everybody make sure your E-Shaft isn't bent everytime you do a rebuild????
Professional rebuilder's do, yes. You are supposed to, as well as check all the journal diameters with a micrometer.

scathcart

The eccentric shaft, which supercedes the crankshaft in a rotary engine's piston counterpart. It is the actual part which is directly connected to the flywheel and transmits engine power.
The rotors sit on the e-shaft.

scathcart

Centripetal acceleration A (rad) in terms of period T (the time for one revolution) is as follows:

T = (2 pi R)/v
A (rad) = (4 pi^2 R)/ (T^2)

Since acceleration is a change in velocity over change in time, and a change in velocity can be determined be a change in driection, and a object spinning is always changind direction, we can determine that a spinning object always experiences acceleration, even a a constat revolutionary speed.

The magnitude of the radial acceleration, is given by A (rad) = v^2 / R, so the magnitude of the net inward radial force F(net) on a object of mass must be:

F (net) = m A(rad( = (m) [(v^2) / (R)]

Since we know the eccentric shaft has mass, and we know it spins, we have therefore proven that it experiences constant force. According to the above proven equations, the amount of force is directly proportional to the magnitude of acceleration.

Any force creates a change in velocity, delta d / delta T. Applying force against an object will therefore cause the object to distort, and create a change in displacement (delta d).


Happy now? Where is your proof?

jeremy

iTrader: (1)

twas a joke man. you guys bicker too much. who cares? everyone think what you like and leave this crap for the lounge. the discussion was decent when it started. info not insult.

by the way, great explanation. can't really get any more detailed without charts and ****. thought about drawing a force diagram in cad and posting since i'm bored to death.

RX-7Impreza

dont you love it when the kiddies get in over their heads???

LOL

Justin

scathcart

All of my argument been factual. Argument is the only method by which to pass information and dispell myth and ignorance.

scathcart

LOL, yeah. It would be one thing if he had a valid point, but "No, it doesn't flex" is not a valid argument. I love even more that he tried that point against engineering physics, the same basic equations that were involved by the SAE teams who DESIGNED the eccentric shaft.

jeremy

iTrader: (1)

nevermind. i wasn't talking about your argument because i agree with you and its basic physics. i was referring to the ruffled feathers that are flying above the argument.

rx7_ragtop

E-shaft flex is a FACT. The eccentric shaft is NOT supported between the rotors. The weight of the (off center) rotors pulls the shaft outward, causing flex at high RPM. This is why "race clearancing" of rotors is needed for extreme high-rpm motors. This is also why Mazda set the redline higher on the later-model motors... the rotors are lighter, allowing higher RPM before flex is an issue. The stock redline is WELL below the level at which flex becomes an issue- remember, they had warranties... you don't set the redline at the "real" limit and then put a warranty on it- that would be a VERY bad business decision.

Brad

scathcart

Fair enough. I admit I may be acting a little belittling, but it is pretty sad to argue under ignorance. I'm sorry if he feels insulted, but in honesty, he brought it upon himself, and was proved wrong with even the most elementary equations of physics.

The condescending attitude is something that comes with being a male, and as I have noticed is quite a bit higher in engineers. We work very hard in are schooling, and it tends to give us a "smarter than thou" attitude, be it earned or not. We are proud of what we accomplish, as engineering physics is one of the hardest faculties to master at school.

Not once, however, did I directly insult this forum member.

I admit my semi-less-than-professional attitude. Can ReZ311 admit he is wrong under factual proof?

rx7_ragtop

Ok folks... FLAMES ARE NOT PERMITTED. This will stay civil, or there will be consequences. You have been warned.

Brad

banzaitoyota

Thats why the aussies sometimes use a two-piece E-Shaft!

scathcart

http://www.gurumotorsports.com/produ...ic_kit_6_1.jpg

FastX7

I just want to pipe in my $.02...

This is how I see it. E-shaft flex is out there... somewhere, in a mystical land, it does exist. Will any of us have to worry about it? Probably not because it's way past the redline and power band of a normal motor? I used to know a guy who shifted at 12-12.5k rpms. Never had a bent e-shaft or broken one. More often than not, it was a thrown seal. So, just to give my opinion... yes, there's such a thing as e-shaft flex. No, we shouldn't have spent this much time arguing it because 99.9% of the people here don't have to worry about it AT ALL (under any sane circumstances).

RX-7Impreza

OMG what the hell is wrong with you??? you are arguing AND WHINING, do you actually read anybodies posts or just browse through them and pick out random words. i wasnt even correcting your grammar , i said you cant hold a simple conversation. grammar on the internet doesnt exist, but understanding what someone types is.

with all of what you have been provided, and your complete lack of understanding in the area of physics, i dont understand how you are still arguing, and with absolutely nothing on your side????

the fact is you have been given the evidence and you refuse to accept it


Justin

FastX7

Guess this post was just... invisible?

dufourmike

iTrader: (1)

true, i may not know alot about the eshaft,or about rotaries,or about cars. but e shaft flex is there. it may only be .000000000001", but it is there.will it affect me when i rev to 7k? no. will i cry at night because of this. no. there are alot of things i can see on a rotary that would break first than the eshaft. i must say you both have good arguments, and are wrong in some ways, and right in others.

OC_

i think theres a reason why our egines dont have rev-limiters.

scathcart

WTF are you talking about?
They DO have revlimiters, an rpm-based fuel cut set 800 rpm above redline.

scathcart

The original question asked if e-shaft flew was a problem. It is at high revs and high horsepower.

A "thrown seal" from a 12.5 K shift is from the E-shaft flexing and running the seal into the housing.

Not to mention I hardly believe this... not only would he have to eliminate fuel cut, but balance his rotating assembly (specifically his clutch) to prevent it from from vibrating and flywing apart. At those levels of mods, I am sure he would have lightened rotors.
Ain't no one shifting at 12.5K on a stock motor. Rev limited, clutch blow up, ignition break up, fuel delivery, powerband....

RX-7Impreza

this forum seems to be just full of wanna be cops. in my opinion that was not a flame. i actually edited it so it wouldnt be. why dont you leave the policing to the people who know how to do it.

scathcart check your pms

Justin