I definitely understand your view of automotive engineers. Seems like nothing is designed to be worked on these days. Case in point: the majority of my colleagues in the mechanical engineering department have never turned a wrench, nor will they ever be required to.
@Will L. Exactly my point. It wasn't crucial, so the OEMs never bothered expending the money to retool for a new piston top. Just a speculative thought.
Pushing the fuel to the sides so it doesn't have good exposure to oxygen to efficiently combust is essentially putting the flame out (at least part of it). Too small of precups cause localized regions of rich fuel condition in the chamber, causing high egts, excessive smoking, and poorer...
@Rockabillyrat yeah much better metallurgy in those blocks. Especially if you even out the coolant flow I'm sure they hold up virtually indefinitely within reasonable power levels. For more longevity I'll stay in the 300-350hp range when I finally get around to building my rig up.
I guess I'm of the opinion that any 6.5 pushing upwards of 400 hp is a time bomb by nature. Sure they can make that much power, but they were never designed to, seeing as they already start cracking apart at OE power levels. The IDI, at best, is outdated tractor level technology. I'm content to...
It is probably the diamond precup causing the wide burn mark there. According to this diagram from the above article, a tighter piston to head clearance makes the jet spread out faster (hc is head clearance here). Imagine the way a bead of silicone spreads out when it's squeezed between two...
To my surprise and great pleasure I found a thread on GM diesels that is less than a decade old. I'm glad to see there are still lots of enthusiasts looking to find design improvements on these engines.
The main topic of this thread, precup geometry, is what led me here. Over the past couple...