Apex Seal Thermal Expansion
#6
Mazda stock seals and RA seals will be very similar in there expansion properties, while the ceramics will change very little in comparison.
The seals are so thin that the change in expansion, even from exhaust gasses, are factored into the machined tolerance in the seal cavity I would think.They should expand around .0015” at a temperature increase of 2000 F*, which is higher than EGTs should be normally. Seal clearance is around .002-.004 so there is a little play there.
I was recently told that you can get up to 30% more torque (in certain RPM ranges of course) from ceramic seals because of lower coefficient of friction values.
But I really believe from reading a lot on the subject that the cost of ceramics far outweighs the benefits for any practical application.
And with the resent foul up of RA I will wait to see how their seals pan out over the long run.
has anyone hardness tested the RA seals against mazda seals yet?
The seals are so thin that the change in expansion, even from exhaust gasses, are factored into the machined tolerance in the seal cavity I would think.They should expand around .0015” at a temperature increase of 2000 F*, which is higher than EGTs should be normally. Seal clearance is around .002-.004 so there is a little play there.
I was recently told that you can get up to 30% more torque (in certain RPM ranges of course) from ceramic seals because of lower coefficient of friction values.
But I really believe from reading a lot on the subject that the cost of ceramics far outweighs the benefits for any practical application.
And with the resent foul up of RA I will wait to see how their seals pan out over the long run.
has anyone hardness tested the RA seals against mazda seals yet?
#7
Originally Posted by rotarypower101' date='Dec 16 2004, 11:53 PM
And with the resent foul up of RA I will wait to see how their seals pan out over the long run.
What's this, I have not heard about this?
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