ATDC, ABDC, BBDC a ? for the gurus
08-04-03, 10:51 AM
#1
ATDC, ABDC, BBDC a ? for the gurus
what is top dead center and bottom dead center considered on a rotary? I would guess the point of highest compression for ATDC which if my math is correct is every 120* of rotar rotation (360/3). but then also what is the ratio of E-shaft rotation to rotar rotation? because ignition timing is based off the crankangle sensor which measures E-shaft position correct? but is port timing(that is givin in service manuals) based on rotation of the rotar or the E-shaft? now if you can makes sence of any of that and know a thing or two i would appreciate the addition of your knowledge 
08-04-03, 12:07 PM
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if you had a piston engine this is basic stuff, funny on a rotary is not.
the rotors are 3:1 vs the eshaft, so a 2 rotor fire every 180 degrees or e ahft rotation, just like a 4 cyl. the cas/distributor is geared to run half of e shaft speed, again like an uppy downy motor. tdc is when the face of a rotor is closest to the spark plugs, on a 2 rotor its every 180degrees of e shaft rotation.
the rotors are 3:1 vs the eshaft, so a 2 rotor fire every 180 degrees or e ahft rotation, just like a 4 cyl. the cas/distributor is geared to run half of e shaft speed, again like an uppy downy motor. tdc is when the face of a rotor is closest to the spark plugs, on a 2 rotor its every 180degrees of e shaft rotation.
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