Mike Baker

I am still wet behind the ears when talking turbos but it seems to me the great design of a rotary engine is inherently prone to bleed by. I get the boost makes more power arguement but wouldn't vulome produce great power without sacrificing as much engine life? I am planning a 20b swap and want to go to a single turbo and hope to get a power boost without killing the motor... any guidance?

Silver7

https://www.rx7club.com/forum/showth...hreadid=127179

Mike Baker

I read the link, I understand the concept of intake - compression - exhaust and how turbo boost applies. This still doesn't address the rotary bleed by due to the rotor gyration. Is this ever an issue when porting and 3mm seals are used?

Silver7

I am not sure what you mean by "bleed by". I have never heard that term used before. Are you talking about air being forced around the apex seal? Apex seals are known to "float". Is this what you are referring to?

Mike Baker

yes, sorry for the wording - the loss due to pressure bypassing seals or close tolerance areas. If you look at the final compression position, there is room for possible loss on both top and bottom apexes. How much does this really occur or is it so minimal that it is ignored?

RICE RACING

Bleed by only occurs with 1 piece seals, it does not happen with self adjusting seals (2 or more piece)

The swing angle of the apex seals you are refering to in the TDC position (maximum swing angle) looks bad but nothing bad happens. the amount of gas pressure underneath the seal is very very large and you only ever get "bleed by" when there is a pressure delay between pressure build up in the chamber v's the underneath of the apex seal, this only happens when the seals to seal slots are clearanced incorrectly or are of a bad design. Pressure does not escape from under the seal because the seal itself tilts in the apex seal slot providing a positive seal against the trailing edge of the rotor groove (3 piece seals do this best).

Hope this answers your question.