Rotary engines and incomplete combustion

[shouldbworking]

Wikipedia said:

Just as the shape of the Wankel combustion chamber prevents preignition, it also leads to incomplete combustion of the air-fuel charge, with the remaining unburned hydrocarbons released into the exhaust

So this would explain a few pops and bangs on the overrun then!

but how much is acceptable? I have recently purchased an 86 rx7 with the thermal reactor removed and it always smells a bit rich and is a bit uneven at low revs with sounds of small explosions in the exhaust. Im not sure whether its a misfire or normal - fuel economy is atrocious but again, not sure if this is normal!

[cptsideways]

Yes its normal

[shouldbworking]

fine going to try and reduce it as much as i can by making sure all the ignition and airflow leads are up to scratch.. magnecor leads on the way

[mave]

Hmm, interesting that Wikepedia says that rotaries don't suffer preignition. I understood that one of the popular ways to kill freshly imported RX7s was to run them on 95RON, get pinking, and shatter the tip seals

[shouldbworking]

Seemed odd to me too.

Found likely cause of this misfiring - ignition system is in a dismal state
Distributor cap and rotor arm both totally shagged, and the universal leads from halfrauds probably doesnt help.

Called mazda dealer...
They want 50 quid for the distributor cap and 90 quid for the rotor arm

Called RX Motors - 40 quid for both. phew, panic over.
Looking forward to holding a lovely set of magnecor leads again, remember them on my xjs.

[mave]

shouldbworking said:

Seemed odd to me too.

Found likely cause of this misfiring - ignition system is in a dismal state
Distributor cap and rotor arm both totally shagged, and the universal leads from halfrauds probably doesnt help.

Called mazda dealer...
They want 50 quid for the distributor cap and 90 quid for the rotor arm

Called RX Motors - 40 quid for both. phew, panic over.
Looking forward to holding a lovely set of magnecor leads again, remember them on my xjs.

Glad you got a decent price. Let us know how you get on!