Spark Plug Info

[mikey]

After much research and discussion with NGK technical, I think I have some useful info for those that are using alumimium heads with 9.5 to 1 or more CR and MSD ignition.

The plug we decided would best suit the Chevy is the BCPR6E-11. Forget the 7's unless you are on the circuit more than half the time and the 11 at the end designates a plug made with a much wider than normal gap as standard - around 44 thou I think. So if you are running close to 10 to 1 CR leave be and if you are below widen by about 5 thou (thats if you are on an MSD)

Th plug also has a v cut electrode which apparently compensates massively for any potential quench inefficiency you may have and allows the flame to grow on every firing. I will have to believe them on this one. I did like the guy as when I asked about Iridium he told me to live with these at £3 a time and only when I was sure get the Iridium which apparently have even better quench improvement characteristics

Aparently a common problem with a two or thre stage cold plug is that you can suffer badly with poor detonation even when warm if you are not gunning the vehicle. My 7's are going in the bin and I will report back on whether this plug works as they say.

Hope this is of use to some visiting the miefield in relation to sparkplug technology.

Think I'll visit the smuuty websute for half an hour now (must remenber to turn AdAware on). Viruses here I come.


Mike

[kdavies3]

I'm pretty sure that's the plug I've been running for the last few thousand miles with no problems. (Iridium version) :thumb::thumb::thumb:
I do get a little trace detonaton at very light throttle which I put down to vac advance needing to be be backed off a bit.

[wilf]

My lump has Edlebrock Vic Jnr heads, albeit a Ford, and seems to be happy with Champion RC12YC which I think are also the recommended fit for Chevy heads.

Nice light brown colour after a hard run, (probably more to do with the carb settings, but still indicates a plug in the reasonably correct heat range) 55 thou gap with the MDS, 9.5:1 CR.