Detonation and Pre-ignition

[MalcolmV8]

Here's a long in depth article on detonation and pre-ignition and related items. I thought it was very well written and covers a lot of detail. Pretty long read but well worth it.

http://forum.tdi-plc.com/white-papers-t ... on-t6.html

[cgrey8]

The main thing I got from the article was that pre-ignition can happen MUCH earlier in the process than I expected. I was thinking per-ignition happened, as he said, a few degrees before the spark fired. But he's saying it can happen as early as when the intake valve is still open.

But he did confirm some combustion chamber designs I've read elsewhere that are better for controlling detonation:

• Small combustion chambers
• Centered spark plug to produce a faster flame front
• Intake charge swirl to cool hot-spots in the chamber in an effort to reduce pre-ignition and detonation
• Compression tumble
• Large quench pad to keep the combustion gasses cool
• Flat top pistons to reduce surface area of combustion exposure

He mentioned those, but didn't elaborate on them at all. Although he did go into a fair explanation as to why hemi heads are the absolute opposite of "good" head design.

[MalcolmV8]

lol I did get a chuckle out of the hemi head section and sent it to some of my mopar friends.