How warped can a rotor housing be and still usable?
I'm not asking what the FSM/Haynes says is acceptable.
I'm asking guys that do rebuilds (sometimes on a budget) what their experiences are...
Because I've got two severely overheated S5 TII housings with about 40k miles that pass visual inspection but are warped..
Thanks.

 

what the FSM/Haynes says is acceptable

 

Ahahahahaha.. This is probably true... But I've got four engines worth of parts and I am planning on tossing together an engine.. Yes, tossing together.
lol..
So, how warped can they be before it is impossible for the coolant seals to not leak? lol

 

find a way to see how flat the trochoid surface is. if the rotor housings got narrow, the wear surface is sagging.

you know sometimes parts are bad, because they are bad

 

The housings didn't get narrow.. They are actually wider in spots... compared to other housings I've got that haven't been overheated.

 

yes, the FSM specs are a good reference. if you have room to work with you can knock down the high spots with a sanding block but don't go much below the minimum thickness.

there is no measure for warpage anyways, it is a measure of thickness variation for the rotor housings. if the variation is too large then there will be small gaps between the irons and the housings, as well the engine may become untrued say if all your rotor housings were thin at the top and thick at the bottom.

what answer were you looking for? every builder has their own specs, some have no specs at all and just use a housing if it looks ok.

 

Okay, this is about the answer I was looking for...
So as long as the width is within .06mm all the way around it will work?
For some reason I was searching for number that the housings width needed be near...
Now I understand...

 

yep and honestly i rarely find any out of spec unless the engine was seriously overheated, in which case if the shrinkage is that extreme then they are too thin.

 

Well... I am young and retarded.. I.E. my engine would overheat and I'd just keep driving...

 

Alright... So I measured all my rotor housings and they are all within .06mm of each other. Around 80.15-80.25. I understand that is .1 but I'm refering to 4 different sets of housings..

 

i think you misunderstand the concept. the concept is to measure each rotor housing at 4 or more spots around the edge of the same housing.

and i think your caliper is a little bit off. even brand new housings aren't that thick. but it should still tell you whether they are within .06mm around each housing.

 

I measured at the spots shown in the FSM.

About the caliper being off, that is possible as it came from harbor freight... lol. I'm going to order a new one after some reasearch on which ones are the most trusted/reliable. Though, as you said, it is still showing all four points for each housing to be within .06mm.

Thanks.

 

the back of the caliper box has the spec, the cheap ones are only accurate to .010"! which is useless

 

Good micrometers for engine building purposes are expensive. Harbor freight is just for ballpark stuff, it's hard to make judgment calls with them.

 

you also have to clean the surfaces before checking the housings. all that buildup is going to throw figures off.

 

The housings I measured are ones I had up on the shelf for awhile and were clean.
However, this will be my first rebuild so I really didn't want to spend money on new parts if I didn't HAVE to have them.. (hard parts)..

 

The measurement at the top of the housing is the 'control' and should be right around 80.00mm. The other three measurements down by the spark plug area should have a variance of +/- 0.06mm.

If you're at 80.15 to 80.25 those housings are junk IMO and any engine you try and build with them is going to have issues.

 

Those housings are junk. Brand new rotor housings have quite a tight tolerance....

 

Now I'm confused but regardless one of the housings was warped enough that one of the inner water jacket seal areas had about an inch of collapsed area sunk in a noticeable amount...

 

Can you post a pic?