Melting pistons.

[Bluemax]

I've watched a video of Kevin's truck pulling with flames out the stack. Didn't think it was over fueling only thought it was late timing. No smoke present.

It looked cool but I still cringe when I see it slowly get taller the further it goes in that video.


That tune had a pretty small PW, low timing, and never commanded above 24,500psi Rail pressure and it eventually bit the dust. I just find it hard to believe that the rail press was the culprit there.
My vote goes to high egt's over time getting the piston temps way to high. At the end of the track at the last pull or two before it blew the manifolds and up pipes where glowing and hot enough that sparks were popping off of them, and I found out when I pulled the turbo off the exhaust housing had been so hot it cracked in a couple of spots that I've never seen one crack before(the divider part of the flange was cracked about an inch or so up into the housing on both sides all the way through), and someone even told me the downpipe glowed about a foot out of the ex housing when they were at the end of the track. And right up till the end it was running the best it ever had. I did a compression test on it the weekend before it blew and all cyl were within 20psi of each other. The night before it blew up the pull I went to had a lighter sled than I'm used to pulling and the pull lasted almost a full minute which is about twice the normal time and egt's were WAY higher than they had ever been and it just didn't run right at all on the way home and the next time I stepped into it, it was all over.

 

[Mike]

It looked cool but I still cringe when I see it slowly get taller the further it goes in that video.


That tune had a pretty small PW, low timing, and never commanded above 24,500psi Rail pressure and it eventually bit the dust. I just find it hard to believe that the rail press was the culprit there.
My vote goes to high egt's over time getting the piston temps way to high. At the end of the track at the last pull or two before it blew the manifolds and up pipes where glowing and hot enough that sparks were popping off of them, and I found out when I pulled the turbo off the exhaust housing had been so hot it cracked in a couple of spots that I've never seen one crack before(the divider part of the flange was cracked about an inch or so up into the housing on both sides all the way through), and someone even told me the downpipe glowed about a foot out of the ex housing when they were at the end of the track. And right up till the end it was running the best it ever had. I did a compression test on it the weekend before it blew and all cyl were within 20psi of each other. The night before it blew up the pull I went to had a lighter sled than I'm used to pulling and the pull lasted almost a full minute which is about twice the normal time and egt's were WAY higher than they had ever been and it just didn't run right at all on the way home and the next time I stepped into it, it was all over.

Just as I remember you saying so when it happened. But, didn't you have a weird vibration in the engine?

 

[Bluemax]

Sure did. Never did figure out what it was. Several people that rode in it commented on it being rougher than others they had rode in. When the crankshaft broke I thought I had figured it out, but with the new LLY crank and a So Cal damper it was exactly the same. Put a different engine in it and it was smooth as can be.:dontknow:

 

[othrgrl]

Everytime I get here and start reading I have all kinds of stuff to say - then it seems by the time I catch up JohnBoy, Mike, or Jon say it.

 

[The Neens]

Everytime I get here and start reading I have all kinds of stuff to say - then it seems by the time I catch up JohnBoy, Mike, or Jon say it.

Yep, same here...Not me, just stuff I've received in PMs...

 

[Fingers]

Everytime I get here and start reading I have all kinds of stuff to say - then it seems by the time I catch up JohnBoy, Mike, or Jon say it.

OK. I'll shut up.

 

[othrgrl]

No keep it up, I just agree and see no reason to post what the three of you have already said. I still don't buy that Wade knew that main injection ended ATDC on the Dodges. I think he meant and thought what he said - that all injection was done BTDC. He also implied that all Duramax's have post injection events and that that is one of the things causing melted pistons. Just shows how much he knows about tuning and duramax's in general.:rofl:

 

[McRat]

Well, I finally took the time to read the whole Dodge CR melting thread instead of just the first post. They seem to be focusing on the differences between CR model years and also water injection, piston design, RPM, injectors, tuning, and steel pistons.

It was actually refreshing to read a thread there where the shops and moderators weren't fighting.

Big injectors didn't seem to help them if I'm reading it correctly.

 

[03 D-max]

So what is the overall verdict of water injection then? it drops egts so isn't it dropping cylinder temperature as well? I have grown up around tractor pulling and with excessive heat you ether turn it back a little or increase the water injection to keep temperatures at bay. I have yet to see a water injection system for our trucks that i really liked.

Or we can put some sparkplugs in and run alky

 

[McRat]

Well, I know a Snow system won't stop it. Perhaps a bigger system might.

I tried to order a "big" system at a Dodge shop, and when they found out who I was, they stopped talking to me.

 

[Dazedandconfused]

:nothingtoadd:

 

[McRat]

I need to make it clear that this issue probably doesn't start to affect Dmaxes until 750HP and up.

 

[Mike]

It will be interesting to see what the pistons look like with a low egt high hp engine that will be disassembled over the weekend. It had a couple of bad injectors and is knocking or rattling.

 

[RENODMAX]

Ok I know this is all very young and we obviously dont have very clear cut method of quantifying how many failures and why. BUT how many guys have had melted .20 or .40 over pistons? I dont know as much as alot of you guys but when I think heat I think surface area. Would a smidge bigger piston help dissapate heat at all? Just a young curious mind

 

[Mike]

OK. I'll shut up.

If you do, I'll call you at midnight for your advice. :angel:


:rofl:

 

[Accelerator]

No keep it up, I just agree and see no reason to post what the three of you have already said. I still don't buy that Wade knew that main injection ended ATDC on the Dodges. I think he meant and thought what he said - that all injection was done BTDC. He also implied that all Duramax's have post injection events and that that is one of the things causing melted pistons. Just shows how much he knows about tuning and duramax's in general.:rofl:

OK then go back and read that first post about the subject, i stated MOST of the fuel should be in BTDC, that is a fact of all Opperating CR systems, like it of love it thats what i posted, long before you and a few other read it the wrong way!

matter of fact i'll find it and post it for you too.

 

[Accelerator]

i can buy that, but IMO if your not spraying most if not ALL your fuel in BTDC your wasting HP.

There it is "Most" :hug:

 

[Accelerator]

reguardless of what you think i know or dont, i have tuned at least one hundred trucks and not had ONE meltdown, even with bad injectors. mine included, nitrous or not, boost as high as 105psi aND 4200 RPM--well before any one had this ability. (thanks to PPE) and 1/4 mile times that most who question me have yet to do!

that should show that i do have a place in this thread to pass on knowledge that i have learned in my own personal expirence's, maybe my way of thinking is different but my tuning track record speaks for itself!

And no i dont allways get across what i mean to in the post i make, i am human.

i just want to try and help resolve the issue's at hand, thats what we all here should be striving to do.

 

[McRat]

reguardless of what you think i know or dont, i have tuned at least one hundred trucks and not had ONE meltdown, even with bad injectors. mine included, nitrous or not, boost as high as 105psi aND 4200 RPM--well before any one had this ability. (thanks to PPE) and 1/4 mile times that most who question me have yet to do!

that should show that i do have a place in this thread to pass on knowledge that i have learned in my own personal expirence's, maybe my way of thinking is different but my tuning track record speaks for itself!

And no i dont allways get across what i mean to in the post i make, i am human.

i just want to try and help resolve the issue's at hand, thats what we all here should be striving to do.

Oh brother, here we go.

You sound exactly like someone I know. "My shop has tuned bazillions of trucks, up to 4,000HP, all of them over 80,000lb and running 4's. We have never seen any problems at all of any kind after two trillion miles, but every single other shop has destroyed every engine they have worked on even at stock power levels, trucks weighing under 900 lb, and running 30 second ET's."

"But while I've never seen the problems you are discussing on any truck I've blessed with SecretTableWater, I'm here to help, because I'm far smarter than any other human in history; I invented the Otto Cycle engine, and know it all."

This is what starts fights on the internet. Us mortals are just jealous in the presence of divine entities.

 

[Brayden]

Oh brother, here we go.

You sound exactly like someone I know. "My shop has tuned bazillions of trucks, up to 4,000HP, all of them over 80,000lb and running 4's. We have never seen any problems at all of any kind after two trillion miles, but every single other shop has destroyed every engine they have worked on even at stock power levels, trucks weighing under 900 lb, and running 30 second ET's."

I think I know who you're talking about... right?