rx racer

I kind of misplaced my rotor ID. now i dont know which goes up front and which goes in the back.

any way of telling? and what will happin if i install them wrong?
thanks

SonicRaT

iTrader: (6)

Time to quickly fastforward the atkins video. Give me a minute

SonicRaT

iTrader: (6)

Ahh, no biggie, there's nothing different

rx racer

ya they are exactly the same.

but i was told that each rotor makes its own wear patterns and the car wont seal if they are put in wrong.

i cant really see any noticeble wear. what do you think will happin

RETed

If the rotor is contacting the housings, you've got bigger problems.&nbsp The rotor actually contacts the housings via a set of seals - it's these seals that actually does the contact.&nbsp There is no trouble getting the front and rear rotor mixed.



-Ted

pengarufoo

it does matter, if you are not replacing the rotor bearings / eccentric shaft. They do wear into eachother differently causing them not to be identical... so you may want to try remember which was where if you planned on reusing the bearings and the eccentric shaft.

Also, if you are reusing apex seals and friends they are supposed to be kept with the rotors (and the correct apexes of the rotors) and these DO wear into the rotor housings, so if you kept them together at that level, they will not match up with the rotor housings wear pattern unless you keep the rotors in the same housings as before.

RETed

The rotor run journal bearings on the inside.&nbsp The rotor bearings are floating on a thin film of oil under normal operation.&nbsp If the rotor bearing is contacting the e-shaft, that is very bad...

So, technically, the rotor does not touch any part of the engine internals when it's running properly.


-Ted

Mr. Gadget

Mix and match, no problem! Ted, is 100% correct. Don't loose sleep over it.

5 point whoa

that could have sucked if they did make a difference.

V8kilr

think about it, when people have a bad housing but good rotor they just buy a used housing "new cost over $400"

how many of those people do you think bought the matching rotor?

or viseversa

pengarufoo

oh yeah, the thin film of oil prevents all wear. right, inspect many eccentric shafts with a micrometer? The front lobe often is worn more than the rear due to the thermopellet's effect @ cold starts.

5 point whoa

Good luck rebuilding your engine man

Project84

there are enough people on this forum (and the planet as a whole) who have reused rotors with a different set of rotor housings with no ill effect. Yes, I, and every other person with any concept of how things work, will agree with you that if you go down to the thousandth of an inch or on a microscopic level, 1 rotor will wear its housing more or less than the other rotor in the same engine. But the intent of the question, matched by all the answers given is that they are interchangeable because practical experience shows (and info provided by people like RETed who deals with this kind of stuff for a living) that the use of different rotor housings do not impede operation of the engine.

There, the issue based on symantics is settled.

RETed

This is why I shim all motors I work on.


-Ted

pengarufoo

Actually, you didnt settle anything. What reted and I were discussing was the bearing wear surfaces. And yes, they do wear differently per-rotor. And if you are reusing apex seals in your rebuild, you especially should keep everything associated properly. It's not the rotor that is wearing into the housing, it's the seals. The only thing directly rotor-related that I am referring to is the rotor bearing and eccentric shaft lobe relationship, which is based on front vs rear just like the rotor housings. When you are rebuilding engines, you are operating down at thousandths of an inch precision levels, so I don't understand what you're talking about.

the more you reuse, the more you need to keep track of. If you lost track of things, you can probably figure htem out by taking some measurements of the clearances between the rotor bearings and the lobes of the eccentric shaft, the sanest combination of the two is likely the proper association. If they are too similar to make any difference, you don't really care.