I am on my 3rd personal Rx7. I have built almost 30 cars, that I didn't own.

Why are all my RX7's eating plugs every 3000 miles?

All the engines, I built seem to have the same situation. I have also noticed a large jump in power and loss of vibration, when replacing the plugs.

Does this seem to be common? All the RX7s I own or built always got new NGK wires with scuff protectors.

Anyone else seeing this running over 100 shots on stock NGK plugs. Does anyone think I should go 1 heat range lower? suggestions>.

 

I usually replace my plugs at 10,000 miles and there seems to be a noticeable improvement in power when I do. I suppose if you want your rotary to always be operating at peak efficiency, replacing them at 3000 miles might be necessary. I don't know why, but rotaries do seem to be hard on plugs.

 

They just run pig rich and burn oil as well. Rotaries just eat plugs thats all. But if your changing them out every 3k, you might just try cleaning them up from time to time to save some cash.

 

I think if you flood them even once you drastically reduce their life.

 

Have had rotories since 1984 and they do like plugs. The '89TII I purchased new gets the plugs replaced every 7000 miles.

 

Thanks for the input. I was thinking, I had a fatal flaw/mistake in all these engines I built.

I would assume, the reason for such accelerated wear is due to porting and running large shots and higher than OEM boost levels. In other words being a better performing engine, it will consume plugs faster than normal..sounds about right.

I would have to say the power improvement is dramatic, if your way past being stock., when you replace the plugs.

 

i replace mine about every 3-5000 miles so, seems right in line with my motor.

 

There's a reason why Rx-8's run irridium plugs from the factory. Their plug change interval is much less frequent. People are getting 30-40k miles out of their plugs, which is ok for a sports car at least.

 

Makes me want to change my plugs this weekend!