And another. /forums/images/graemlins/eek.gif I'll try to stop after this, but here are a few more. Another from a CTD advocate and one from a DMax tech VERY involved in the high performance diesel arena.
CTD guy:
[ QUOTE ]
I think a lot of us Cummins guys already have respect for the D max, but we ain't skeerd. The fact of the matter is that with the nitrous that the bigger hp D maxes are spraying now, I think the bottom end of the motor is already near its limit. With the bigger turbos, likely you guys will be able to burn more fuel and make similar max power as now without using the drugs. My guess is that you won't see guys ultmately making a whole lot more power than what they are now without some bottom end work. Either way, it certainly is impressive how that motor can perform with relatively little work. For the big numbers its the same for everyone, you want to play you have pay.
Craig
[/ QUOTE ]
Tech:
[ QUOTE ]
Craig, I agree with you, but so far the Dmax bottom end has proved to be a rather stout unit, failures are very few and far between so far... Not saying improvement can be done, but we are sure better off then the Pstroke guys I think I heard 450 rwhp is all theya re good for... that's gets expensive
I know of more thena few 600+ dmaxs with stock inards.
Asking this truthfully, not trying to piss in the wind, how are the Cummins holding the power? I know that o-rings on the heads and such are used for the higher boost, but are mods being done on the rotating assembly?
[/ QUOTE ]
I also found a reference to that DMax the blew the side out of the block when the guy claimed it was his fault. Turns out he fed it "liquid propane" which would be a huge no-no that no (reasonable) engine could survive... Here is the quote:
[ QUOTE ]
Clint found the limit by giving her liquid propane from what I understand. That is not a fair test for the bottom end, as the Cummins will also fall apart with that kind of abuse. I know 3 guys that have tried propane on the Cummins, and when it got a drink of it that was all she wrote. I don't know of anyone that has found the limit when doing it right. Sure there are a few that met their water Lou, but you can say that about any engine. That is how the limit is found.
[/ QUOTE ]
And finally, a first hand account of what those aluminum heads and that "weak" bottom can handle...
[ QUOTE ]
Clint was seeing about 60psi with the twins. He did shoot in liquid propane to get more power and at first bent two rods, fixed it, tried it again and bent all eight. But the head held. I think we will see a unprecedented amout of pressure that this thing can hold. I've held the rods in my hand and they are extremely stout. The reason Clints bent was because of hydrolock. That is a pretty small combustion chamber when at top dead center. We must remember, Isuzu has been building these things for about 80 years now, and half of that with turbos and some with aluminum heads. They have done there home work weather or not every one want to belive it or not. They have been the number one builder of mid size diesels for over 60 of those years. I think the future hold some great thing for the Dmax. I have pesonally run the Extreme, healthy shot of propane, huge shot of N2O to clean it up (the opening to the engine is the same size as the one in the hose coming off the bottle), and have bravely injected over 1450ml per min of 50/50 water/nitro into the engine at 220 psi with no problems. I don't recommend this however, but it is a monster. Pretty scarry when you don't have a back up motor. I did toast the C2s, C3s, and C4s in the tranny with the second run with this.
[/ QUOTE ]
Lots of other cool info in that thread including a few bits contrary, but not supported...
CTD guy:
[ QUOTE ]
I think a lot of us Cummins guys already have respect for the D max, but we ain't skeerd. The fact of the matter is that with the nitrous that the bigger hp D maxes are spraying now, I think the bottom end of the motor is already near its limit. With the bigger turbos, likely you guys will be able to burn more fuel and make similar max power as now without using the drugs. My guess is that you won't see guys ultmately making a whole lot more power than what they are now without some bottom end work. Either way, it certainly is impressive how that motor can perform with relatively little work. For the big numbers its the same for everyone, you want to play you have pay.
Craig
[/ QUOTE ]
Tech:
[ QUOTE ]
Craig, I agree with you, but so far the Dmax bottom end has proved to be a rather stout unit, failures are very few and far between so far... Not saying improvement can be done, but we are sure better off then the Pstroke guys I think I heard 450 rwhp is all theya re good for... that's gets expensive
I know of more thena few 600+ dmaxs with stock inards.
Asking this truthfully, not trying to piss in the wind, how are the Cummins holding the power? I know that o-rings on the heads and such are used for the higher boost, but are mods being done on the rotating assembly?
[/ QUOTE ]
I also found a reference to that DMax the blew the side out of the block when the guy claimed it was his fault. Turns out he fed it "liquid propane" which would be a huge no-no that no (reasonable) engine could survive... Here is the quote:
[ QUOTE ]
Clint found the limit by giving her liquid propane from what I understand. That is not a fair test for the bottom end, as the Cummins will also fall apart with that kind of abuse. I know 3 guys that have tried propane on the Cummins, and when it got a drink of it that was all she wrote. I don't know of anyone that has found the limit when doing it right. Sure there are a few that met their water Lou, but you can say that about any engine. That is how the limit is found.
[/ QUOTE ]
And finally, a first hand account of what those aluminum heads and that "weak" bottom can handle...
[ QUOTE ]
Clint was seeing about 60psi with the twins. He did shoot in liquid propane to get more power and at first bent two rods, fixed it, tried it again and bent all eight. But the head held. I think we will see a unprecedented amout of pressure that this thing can hold. I've held the rods in my hand and they are extremely stout. The reason Clints bent was because of hydrolock. That is a pretty small combustion chamber when at top dead center. We must remember, Isuzu has been building these things for about 80 years now, and half of that with turbos and some with aluminum heads. They have done there home work weather or not every one want to belive it or not. They have been the number one builder of mid size diesels for over 60 of those years. I think the future hold some great thing for the Dmax. I have pesonally run the Extreme, healthy shot of propane, huge shot of N2O to clean it up (the opening to the engine is the same size as the one in the hose coming off the bottle), and have bravely injected over 1450ml per min of 50/50 water/nitro into the engine at 220 psi with no problems. I don't recommend this however, but it is a monster. Pretty scarry when you don't have a back up motor. I did toast the C2s, C3s, and C4s in the tranny with the second run with this.
[/ QUOTE ]
Lots of other cool info in that thread including a few bits contrary, but not supported...
