(http://www.hammerperf.com/images/acrplugs.jpg)
CNC machined from 6061T6. Weldable and machinable.
The readily available steel plugs do nothing to eliminate the fuel trap and are problematic for machining angled squish bands. Welding the hole, it's difficult to get the thickness you need with good penetration deep in the hole.
Not happy with either of those approaches, we programmed up the CNC and made these. They work great, we've done several nice 30 degree chambers using them. We figured we can't be the only ones facing this problem so we decided to make them available to all. Purchase online here: http://www.hammerperf.com/tctopend.shtml#acrplugs (http://www.hammerperf.com/tctopend.shtml#acrplugs) , or contact us for dealer pricing: http://www.hammerperf.com/contactus.shtml#salesform (http://www.hammerperf.com/contactus.shtml#salesform)
(http://www.hammerperf.com/images/hsjamescuenca.jpg)
Here's a set of 110 heads we did recently, where we 30 degree'ed the chambers using these plugs.