How many spark plugs in a rotary engine

I'm not sure why Mazda elected to run separate distributors and usually coils for the leading and trailing plugs, though. My guess is that they either fire simultaneously or quick enough in succession that one coil wouldn't be able to recharge quickly enough to fire both properly. I seem to remember that the trailing plugs only fire under certain conditions, like either only over a certain rpm or under a certain rpm. Trailing plugs fire a few degrees after the lead plugs for a not-insignificant increase in fuel efficiency.

Early 10a and 12a engines had twin distributors until they worked out how to utilize one distributor reliably. But actually 3 wires in a distributor does make sense. I think the coils were the main limiting factor in the FB's 7k redline You'll need to log in to post. Log in. Login Digital Edition Buy a Subscription. How does a rotary engine's ignition system work? I think you're miscounting the number of plug wires.

But you still had twin coils. This makes a rotary engine not only more compact but also less complex with fewer parts requiring maintenance, lubrication or replacement. Less vibration, higher RPM. As the only moving components in a rotary are rotational parts, it produces considerably less vibration than a piston engine. Doing away with camshafts, rockers, timing belts, gears and most importantly valves and valve springs means a rotary engine can also achieve much higher RPM.

Despite having plenty of street and race cred, rotary engines are often labelled as unreliable and difficult to tune. The truth is that with a quality engine management system and a good tune, a well-built rotary engine should provide you with many years of peak performance.

A rotary has half the available processing time of a piston engine. It means you have to inject the required amount of fuel and charge the ignition coil in half the time approx 10 milliseconds at rpm compared to an equivalent piston engine. Remember that as the revs climb the demand on your fuel and ignition system increase. Running lean and engine misfire are the enemies of a rotary engine — avoid them at all costs.

Rotary engines use two spark plugs per rotor, a leading and a trailing spark plug. Trailing plug mounted above the leading plug fires degrees after the leading plug and completes the combustion providing a more uniform flame front across the rotor face.

Ignition Split Timing is the angle the trailing plug fires after the leading plug. The lower the split timing the more chance of engine damage. Typically, setting your entire split map at 10 degrees will yield good results with the least chance of engine damage. The timing should only increase a few degrees across the whole rev range. We recommend that a drop of engine oil be applied to the threads, and using our Thin Wall Spark Plug Socket.

Intake Systems. Carburetor Applications. Fuel Pressure. Carburetor Tuning. Misc Tips. Fuel Injection. Ignition Systems. RX-8 Ignition. Water Cooling. Drive Line. Exhaust Systems.