mazda rx2 rotary

here we go again let us see what what you think.i am trying to understand this rotary engine concept.simple three moving parts simple that is true.but the ignition timing,spark plug location in the rotor housing and true top dead center is my question.i understand the whole ignition timing thing at least i think i do.under vacuum this is what i have about 28 degrees at idle and 40 degrees at 3000 rpm and above.as for the boost side of the map 0 psi to about 8 psi at 3500 rpm i take about 15 degrees out of the ignition map then give it more advance as rpm goes up.at 8 psi at 3500 the timing is at 25 then advances up to 34 at 8000 rpm. every thing from this point i am taking timing away.the trailing is set to a flat 20 degrees.this is my problem with tdc/ ignition timing.i have this third gen with a first gen front cover.i am running the third gen water pump alternator and pulleys(e-shaft unorthodox pulley).no way to time this engine.i have read some posts on how to find tdc by locating the apex seal in the spark plug hole leading and trailing then split the difference,there is your tdc.this is not true for the third gen not sure about the earlier engines.the reason i say this is because the spark plug holes are not located in the center of the rotor housings.the spark plug holes are about 1/2 inch higher (advanced) in the rotor housings.in the leading spark plug hole, the apex seal is at center about 120 degrees btdc.in the trailing spark plug hole the apex seal is centered at about 105 degrees after tdc.that is why i say the "center the apex seal in the spark plug hole" theory is not accurate.it would be about 5 degrees off.as for the "combustion chamber"the leading edge of the chamber at 45 degrees btdc, is in the center of the leading spark plug hole.the trailing end of the combustion chamber at the trailing spark plug hole is at 30 degrees after tdc.what is the reason for this.with the spark plugs holes "advanced" (above center) in the rotor housings is this why some people seem to run so little ignition timing?i know fuel has alot to do with timing but what is this about?the only way to find true top dead center i think would be like this.measure the rotor housing from top to bottom.mark a center line on the spark plug side.measure the rotor from apex seal to apex seal on one face of the rotor.find the center in between the apex seals.mark a line.now line up these two lines.install your e-shaft pulley and make your new TDC mark.how do you all do it with mismatched front covers and pulleys?will a turbo 2 e-shaft pulley with a first gen front cover and timing marks give true readings on my third gen engine?who really knows?

mazda rx2 rotary

i will trade you the map to the HOLY GRAIL if you let me in on this bigger secret.

ultimatejay

iTrader: (1)

I had three different crank pullies and the TDC mark was in the same spot on all three. The only difference was the marks for the trailing. So, I could be wrong but I think all the TDC marks should be the same.

61620B

it looks like you guys never sleep.........thinking about the dynamics of the engine and how it works all day long and even have nightmares about it,its a mental phase and everyone gets infected....i know some people who have this rotary disease

But you guys are all in the write track,just play with it more....

13B-RX3

iTrader: (2)

I had your same problem. I was pretty sure timing was correct but i wanted to be sure. I paid $60 IIRC for a racing beat one piece pulley, slid it on, lined up the marks, and then put my old pulley pack on. I then marked my old pulley so now i know for a fact everything is good, just get the pulley to suite your cover. It's a small price to pay for piece of mind!

mazda rx2 rotary

i know there is a AA meeting even an NA meeting.Is there an RA (rotorholics anonymous) meeting i can check myself into?if i am not at work i am thinking about this stuff.hell i am thinking about this stuff at work.i think my first step in beating this disease is a 9 second pass.once i get past my first step i know it will only get worse.