for discussion: a drawing of Renesis side seals
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for discussion: a drawing of Renesis side seals
It looked interesting so I clipped it out of the Mazda RX-8 press kit.
"RENESIS employs a new cut-off seal located between the rotor's dual oil seals and side seal. This sealing arrangement eliminates blow-by between intake and exhaust ports and prevents carry-over of exhaust gas to the next intake cycle. Side seals are a new keystone-type with wedge-shaped section. Exhaust gas build-up against the side seal can easily cause carbonization, but with the wedge-shaped or cuneiform side seal, the seal shape is optimized to remove carbon. The shape is also more congruent to its opposed frictional surface, achieving much bettersealing proficiency."
"RENESIS employs a new cut-off seal located between the rotor's dual oil seals and side seal. This sealing arrangement eliminates blow-by between intake and exhaust ports and prevents carry-over of exhaust gas to the next intake cycle. Side seals are a new keystone-type with wedge-shaped section. Exhaust gas build-up against the side seal can easily cause carbonization, but with the wedge-shaped or cuneiform side seal, the seal shape is optimized to remove carbon. The shape is also more congruent to its opposed frictional surface, achieving much bettersealing proficiency."
Last edited by inittab; Jan 9, 2003 at 11:03 AM.
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Originally posted by j9fd3s
hmm thats very interesting, in the pre 74 engines they use double side seals, it looks like they are going back to that?
hmm thats very interesting, in the pre 74 engines they use double side seals, it looks like they are going back to that?
I'm wondering how the new "circular" cut-off seal eliminates blow-by between intake and exhaust ports?
This new cut-off seal should also help protect the oil rings from combustion gases as well. I guess in theory this should reduce or eliminate the signature "startup smoke" of the old rotaries.
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actually..... now that I think more about it, that cut-off seal is an absolute necessity with the side exhaust ports. Those oil-rings would burn up in no time without it.
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Originally posted by inittab
actually..... now that I think more about it, that cut-off seal is an absolute necessity with the side exhaust ports. Those oil-rings would burn up in no time without it.
actually..... now that I think more about it, that cut-off seal is an absolute necessity with the side exhaust ports. Those oil-rings would burn up in no time without it.
mike
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And it doesn't spit out unburned gases. It just brings them back around to be burned again. They claim it reduces exhaust emissions to one tenth the amount recorded for the previous rotary engine. nice!
Last edited by inittab; Jan 9, 2003 at 01:33 PM.
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I theorized that they'd need to put a seal there several months ago, because of the exhaust gases being exposed to the sides of the rotor at the same time intake manifold vacuum is exposed to the side of the rotor. By the same pronciple where high intake manifold causes worn engines to smoke heavily (sucks oil past the oil seals when the vacuum is applied to the side between the side and oil seals) the intake *would* have some communication with the exhaust.
https://www.rx7club.com/forum/showth...ion#post864302
Thinking along the right lines
https://www.rx7club.com/forum/showth...ion#post864302
Thinking along the right lines
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