apex seal clearancing was mentioned in a thread discussing the RWS/rotary aviation apex seals. i bought the RWS apex seals and i am getting ready to rebuild a s5 t2 engine. i'm wondering if anybody else out there clearanced their apex seals before installling them. i know judge ito does this, but i've tried emailling him and have yet to receive a response. i would like to know exactly how you do it and what you use to do it with. judge ito builds some really heavy duty engines and if it works for him, i'm sure it's a MUST to ensure you have a reliable engine. and i'm also curious as to what tolerances you would need between the apex seal and groove for a turbo engine, as i'm sure it would be different than a NA engine since turbos make more heat. any help would be appreciated, and i'm sure if there is good info involved, we might get this archived since there's nothing in there about this topic.

 

bump

 

i think you HAVE to check clearence on them or run the risk of binding/ premature ware. You pretty much put the seals in the slots and then measure the clearence with a fealer gauge, then put a piece of 600 grit sandpaper on something flat like a piece of glass and rub the seal lightly, then re check. I think ito runs .002,.. but im not sure, you should ask him himself.

http://www.mazdamotorsports.com/weba...1&subject=apex

 

I picked up a $20 digital caliper and measured the housing, then matched the seal to that. And use emery paper.

-Ben

 

If you mean the end clearance, the rebuild manual gives you a stock clearance that works fine. Special "clearancing" which you may have heard of refers to setting a larger gap between the seal and rotor grooves than the manual calls for, in order to allow for the added expansion of Atkins apex seals. RWS seals are not Atkins seals.

My RWS seals came out to be exactly .002 in. clearance between the seals and rotor grooves for all six. The engine has 4500 trouble free, "spirited" miles on it and is a six port street ported NA.

Clearancing of Atkins seals is documented on the other rotary enthusiast site under "rotary engine building and porting".

 

**** i have atkins seals, and i only matched to the housing. I wonder if it will be fine, i dont have the engine all the way together yet...

 

but my car is turbo, and since turbos creat more heat wouldn't i need to increase the clearance a little?