rawbutt

I'm certainly no mechanic, so this question may be very dumb, but I'm getting a little detonation and wondering if a colder plug could help? Or colder/hotter plugs only for when you're fouling plugs, etc.? I've read some posts suggesting to go one step colder for every 75 hp or so. I've probably picked up 125 hp after my 383 overhaul from stock and still running A/C Delco platinum tips that I ran prior to the rebuild (new ones of course). I've got a MadZ28 tune and have had it dyno'd. The first pull showed just about a perfect A/F ratio and the second pull seemed be a little richer for some reason.

Anyway, just looking for any suggestions on plugs. Should I move one step colder to something like an NGK-TR6 and see how it goes? As a side note, I'm thinking of having an MSD 6420 and Blaster coil installed at the same time in case that matters. Also thinking of replacing the stock Delco plug wires with something a little better if it is suggested?

Thanks in advance!

Robert

97WS6Pilot

When I went to a colder plug (autolite 104) I had problems with fouling. I'm using the stock autolite 106's now with no detonation.

OBE1 95Z28

I would use a colder plug and a non-platinum plug. The platinum plugs will run hotter and not help a detonation issue. Autolite 104 is a good choice.

rawbutt

so you'd recommend going two heat ranges colder than stock for my application? i believe an autolite 104 is two colder right?

robert

Injuneer

There's a good spark plug info thread "stickied" at the top of the "N2O Tech" fourm listing. Might want to check that out. The person who put the 104 data on there indicates it is between 1/2 to 1 full step colder than stock. I've always treated it as a full step colder. Its definitely not 2 steps colder..... that would be the AutoLite 103.

I run the 104 with my stroker for NA use, about 500 flywheel HP, and have had no problems with fouling the plugs or with detonation. I run the 103 with a 125-shot, and it works fine in the 625HP application. The 103's do tend to foul a bit with extended periods of low power driving and no use of nitrous.

If the tip of the plug gets too hot, you run the risk of burning the electrodes off, and in extreme cases you run the risk of turning the engine into a glow plug application, with pre-ignition as the piston rises. That's a little different than detonaton, which is the term generally used for a second flame front autoigniting after the plug fires..... either can do some serious damage.