I'n my work with automotive, ag & OTR 4 stroke diesels I've never heard of overheating caused by chamber shape. As a matter of fact, we have great difficulty making enough heat to warm a pickup cab. Charge motion is something we manipulate to gain performance targets. We is tumble, swirl or quiescent motions to control thing like idle quality, or high end power.

In a 2 stroke diesel with Schnuerle porting the charge motion would be a combination of swirl and tumble which I'm sure would make for very good combustion characteristics but I'm not sure what effect a squish band has be it flat or conic. Not being familiar with the engine in question, or to be honest Schnuerle ported diesels in general I can't really make any authoritative comment. However, with what I do know, I would say there is a chance that hot spots could develop in such an engine. The angled squish band would tend to direct the burning charge toward the center of the chamber, where you want it where a flat band would create a hot "band" if the squish clearance were too large. At least that's what I theorize. AJ has mentioned that in his experience chamber shape in our little diesels seems to make very little difference and I would have to agree that I've found the same thing. But in these high performance applicetions I'm not so sure we're not getting into the range of operation and combustion characteristics where chamber shape is becoming more critical.

Really I'm just thinking with my fingers but thought I'd share my thoughts and see what comes back.

Randy