A while ago SCC published an article about finding "free" hp in your motor. One of the mods was to open the spark plug gaps 0.005+ over the stock gap (good for 2-3hp). Being a guy who likes free stuff, I thought I'd give it a shot. I pulled out my plugs and opened up the gaps from a stock 0.042 to 0.046 (just didn't feel comfortable going 0.005 bigger). The results after 3 days? Slight high rpm detonation which is something I've never heard my engine do. I pulled my plugs and sure enough, they had shown slight signs that there was some detonation going on (slightly grayed electrodes). I regapped the plugs and put them back. No more detonation.

I just wanted to let everyone know before they ruined a nice set of NGKs.


Dave

 

Excuse my ignorance, but how do you change your spark plug gap? I recently took a look at mine, and they look fine. The only people I've seen actually change the gap are guys running NOS.
Thanks.
-hype

 

you take your spark plugs out and you use a gapping tool which basically pries the gap wider.