apex seal groove gaps
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Junior Member
Joined: May 2007
Posts: 42
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From: brisbane
apex seal groove gaps
hi all
have just measured up some S6 rotors i wanted to use for a build, pretty sure they are with in mazda spec, but may be a bit on the loose side in terms of best performance.
I found the grooves at the corner seal tips have a bit more gap compared to the center of the rotor, and the #1 face has a tiny nick taken off the leading edge as per photo.
have had some people mention to gently tap the corners in and then lightly file the correct gap, i plan on using 2mm e&j 3 piece seals which i already have.
any advice is appreciated
have just measured up some S6 rotors i wanted to use for a build, pretty sure they are with in mazda spec, but may be a bit on the loose side in terms of best performance.
I found the grooves at the corner seal tips have a bit more gap compared to the center of the rotor, and the #1 face has a tiny nick taken off the leading edge as per photo.
have had some people mention to gently tap the corners in and then lightly file the correct gap, i plan on using 2mm e&j 3 piece seals which i already have.
any advice is appreciated
Last edited by joshrulz; Aug 10, 2017 at 06:55 AM. Reason: pics didnt work
Joined: Oct 2001
Posts: 6,279
Likes: 728
From: Florence, Alabama
good for you for actually measuring things
almost all used rotors show approx .006 at the ends of the apex seal grooves and around .003 center.
there are 3 fixes.*
new rotors
lightly "adjust" tap corners being very careful to not over-adjust which will effect corner seal clearance. lots of tricks here.
swap in a set of Goopy +.004 2 mm apex seals which will reset end clearances to .002 and require filing of center groove as well as corner seal slots. lots of work but .002 across the slot.
i understand you are already committed to a set of seals that preclude this avenue but others might benefit from this solution.
suggest you find an appropriate rubber hammer and get tapping.... just keep an eye on the corner seal clearance.
good job on the measuring.
*
2 mm apex seals at 9000 RPM exert approx 30 pounds of centrifugal force against the rotor housing.
3 mm apex seals add an additional 15 pounds of grinding force against the housing.
back in the day they were the "fix" for wounded apex seal slots. the last thing a housings surface needs is 50% additional grinding force against it.
by adding .004 to the 2 mm seal Goopy solved the sloppy groove problem.
my gram scale shows both the Goopy 2 mm Std and .004 oversize at 8 grams or .30 oz.
the 3 mm comes in at 13 Grams and .45 oz.
almost all used rotors show approx .006 at the ends of the apex seal grooves and around .003 center.
there are 3 fixes.*
new rotors
lightly "adjust" tap corners being very careful to not over-adjust which will effect corner seal clearance. lots of tricks here.
swap in a set of Goopy +.004 2 mm apex seals which will reset end clearances to .002 and require filing of center groove as well as corner seal slots. lots of work but .002 across the slot.
i understand you are already committed to a set of seals that preclude this avenue but others might benefit from this solution.
suggest you find an appropriate rubber hammer and get tapping.... just keep an eye on the corner seal clearance.
good job on the measuring.
*
2 mm apex seals at 9000 RPM exert approx 30 pounds of centrifugal force against the rotor housing.
3 mm apex seals add an additional 15 pounds of grinding force against the housing.
back in the day they were the "fix" for wounded apex seal slots. the last thing a housings surface needs is 50% additional grinding force against it.
by adding .004 to the 2 mm seal Goopy solved the sloppy groove problem.
my gram scale shows both the Goopy 2 mm Std and .004 oversize at 8 grams or .30 oz.
the 3 mm comes in at 13 Grams and .45 oz.
Last edited by Howard Coleman; Aug 10, 2017 at 10:20 AM.
