This weekend, I built my 4th motor. I decided to try out the new ALS Side Seals. Here is my experience with them:

Pros:
- Durable
- Not brittle
- Will not break

Cons:
- They come way to long ( I spent 10 hours or so clearencing them )
- They bend VERY easy in all directions (Some were so bad I couldnt bend them back)
- They are not smooth like OEMs and sometimes catch the side seal groove

Conclusions:
I will not be using them to rebuild any more motors. The stock side seals are more then adequate for 95% of applications. The ONLY 2 cases in which I would use ALS side seals would be if it was a high boost race only motor, or if I had insane amounts of time to use clearencing and extra ALS side seals to use if the ones I were working with became distorted.

Out of the 12 brand new ALS side seals. I only was able to use 6 because the other 6 were too distorted after clearencing to be used. They are way too soft. 1 of my rotors has ALS side seals and the other one has OEM reused seals.

 

Hmm based on your post, it would appear that one would have to use a junk rotor as a jig to clearence and keep straight.

 

Gentle hands or professional piston ring filer...

 

Yeah, sounds like you mandhandled them by trying to sand them by hand. Like mentioned above using an old rotor you can make a tool that would clearance them without bending them.

Here is a good thread regarding some nice home made tools for clearancing.

https://www.rx7club.com/rotary-drag-racing-167/got-bored-work-today-839432/

 

They would be ok if I had an old rotor to use.