MTomac said:
I got $100 on any Duramax against Hoot's Cummins in any dyno, pulling, racing, ect. competition.
I can tell you what I got right now Mike. My last dyno was 423/960. TST PowerMaxCR set on 5/5. No other mods except straight pipe and cleared out intake. Without a trans upgrade and almost 50,000 miles on the stock trans I'd be leary of doing much higher on the TST at full throttle loaded.
I've already layed away a few Dmaxes on the dyno including my old one.
I'll send you my address for the check.
So maybe I'm stupid and don't know the exact causes of piston and block failures on beat up Duramaxes. I also don't know the exact causes of injector failures or headgasket failures on Dmaxes. Eric is not short on work that's for sure. Does anybody know the causes? At least with the Cummins there usually is a simple explanation... . KDP... Killer Dowel Pin... . dowel pin falls out taking out geartrain. Block crack... . bad casting (53 Block) etc.
nwpadmax, OK I'm in the wrong forum and I'm BS'n out of my league. I apologize.
I really don't give a rats a$s though that you don't like it. But I'll apologize anyway for getting you upset.
Anyway... . I'm reading here... .

and it seems there is more than one reason Dmax pistons have failed. Too much fuel, too much timing, too much boost, or not enough piston. Which is it? All of the above? Cylinder temps get too high for too long? ... the old egt thing? Pistons overheating/melting could be a clue

Energy is heat. The pistons are failing because they can't take the heat. OK control the heat... no wait. less power... add heat... need more cooling... . got that... less power... need more heat...
There is a point of power level that the pistons and other parts for that matter simply can't handle. We are all well aware of that. I think diesels are a little harder on the piston than gassers. I could be wrong. No wonder they cool them with oil. At some point the oil simply cannot remove the heat fast enough. On top of that you're superheating the oil. Maybe the Dmax design from an overall standpoint, with respect to 600-700hp simply doesn't cut the mustard. Hows that for technically speaking?
All I was saying earlier in the thread is I believe the much taller piston in the Cummins is a better design for diesels and from a starting point for higher power levels, what more could you ask for? Add the stouter rods and overall stouter design and you have one heck of a stock motor to start with. Didn't they recently break into the 7's with the Cummins? But yea the higher rpm capabilities of the Dmax are more appealing in some respects.
I don't have enough free cash to do a whole lot with my stuff but just because somebody throws money at something does that make them experts?
BTW I in no way claim to be an expert in any way. But on this forum/website we can talk freely about Dmax issues without the whole friggin site hammern down on you. It's a joke over there when somebody honestly tells it like it is.
I must say it's good reading over there.

You have the superknowledgable with the years of experience and high tech tools. Than you have the "lets try this" techs who just see what breaks and looks at the signs to determine what the cause was. As was said, there is no tool available in the crazy world that can really show you what's happening.
You can look at a design and compare it to another and get a feel for what's going to hold up better, as long as the designs are sound to begin with. They use the latest and greatest simulation and FEA tools that most of us don't have access to or the wherewithal to use. Apparently Isuzu ran their anaysis which took 4 years :-laf to run before they discovered the block weakness. From what I gather from READING the high power postings is its in a try it and see mode right now and a lot of speculation. Think about the Cummins design and it's heritage and think about the Duramax design and it's heritage. Cummins purposely built a 350,000 mile diesel. Dmax set's it at 200,000. Why the big difference? RPM related? Seriously... not to be smart. Why the 200,000 mile rating? Wouldn't you want to present the best you can do? What the hell good is 365hp stock? The BS hp/marketing kills me.
Notice Ford is using the new 6. 7 Cummins in the 2008 650/750 med duty trucks? Go figure.
It's all banter... hope I didn't get personal with anyone