meltdown -- common rail style

jlibert said:
Unless someone can convince me otherwise, It's going back stock. CR engines have a lot of potential, but we haven't got them figured out enough for me to feel confident in another build. Even if we could make them live in extreme conditions, we aren't making any power above 3200 rpm. Add upcoming CA smog regs to the picture and all of a sudden 12 valves make a lot of sense.

I have a 92 regular cab 4x4 ready to go.


-jp
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Sorry to hear man. I was looking at building around what you have on my 07. Funny how some CR guys though Jeff G was crazy for putting a 12V in a 3rd Gen 1500, but i think maybe he is smarter than us all. Plus that thing was sooo sweet!
Brian
 
huh jeff prob put a 12v in it because its cheaper...lol plus back then cr werent making power they are now.
 
Why isn't anyone answering if the cr's with melted pistons were running different cams other than stock?
 
these pistons work great in a p-pumped truck. the bigger bowl lets you get more timing dialed up without spraying on top. havent melted any down in builds like that. very high temps hard runs big power flames out of the stack.
http://www.phdperformance.com/ted%20wilmington%202nd..mpg. forgive the end please 14mm pump stuck and my but puckered when i should have been pullin the kills hit right at 7200 rpm. 04.5 pistons with valve reliefs cut. lived thu it just fine

ted
 
regular 24v nozles im not at the shop to look what they are and dont remember. they did cover pretty much the entire bowl diameter at 40-45deg timing but also hit where it needed to be as the piston came up. accually was about perfect for that..

im not trying to high jack this thread just stating that these pistons will take a beating without turning to goo. saw over 2000 degrees at the pyro several times no melting. the first year it was p-pumped i couldnt run water 2200 deg before the sled was movin good was the way she ran. factory pistons uncoated.

ted
 
Thanks for replying, is that a big part of the problem, stock cam not moving enough air?
 
Smokem said:
They would be 153°, this is my point. The contact pattern of the 124° injector is much larger than that of the 143° or 153°, thus raising the surface temperature of the piston.
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I see that Bean used the 555 143's in the last build, and that was one of the best melt job's I've seen.

I'm going to go out to the shop and make a cross section of a 04.5 piston and post it, might show a issue with thermal conductivity.
 
I'm stealing this photo from another member's post, and this is a classic 04.5 up piston melt, and I can't count how many I've seen just like this, kind of just there, not quite chernobyl yet.

The lower bowl of the piston can handle the heat fine, its that top outer ring that can't, and were it usually always starts from.

attachment.php



Now look at a cross section, there's a healthy chunk of meat above the ring land thats exposed, yet not much to soak back to the piston, also with the ring land higher, it is that much hotter as well, and don't conduct as well as the piston.

pistoncrosssection007.jpg
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I'd like to see a cross section of a 03-04.
And I'd really think about switching to that piston/nozzle combo if you plan on putting the screws to it.
 
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aer212 said:
Thanks for replying, is that a big part of the problem, stock cam not moving enough air?
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I don't think so. If that were the case the trucks would be rolling coal and not cleaning up the fuel as well as they do. Jlibert's truck runs almost smoke free at WOT. I Think the pistons can't handle the extreme cylinder temps the high hp CR are making. The EGT gauge is useless if you are burning all the fuel in the cylinder and there is none left in the manifold.

Joe
 
so can anyone answer my other post, can i run 03-04 pistons as long as I switch to 03-04 nozzles, will my ecm still work with the older tips and also the 06 bodies? Im thinking of doing this almost as a guine pig...lol I can get a set ceramic coated and teflon skirts for a great price. thanks danny
 
outlaw99 said:
so can anyone answer my other post, can i run 03-04 pistons as long as I switch to 03-04 nozzles, will my ecm still work with the older tips and also the 06 bodies? Im thinking of doing this almost as a guine pig...lol I can get a set ceramic coated and teflon skirts for a great price. thanks danny
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I can't answer on experience, so take for what its worth...

However if I remember right, John Robinson has done it...03 pistons/injectors 05 ecm, and turned out good.

I think that was a while back, so he must be ahead of the curve. Not sure what the reasoning or why the switch.

Frankly I don't see why not, but not sure of anyone else who is, there is a couple of issues, one of nozzle sizing, the 03 electronics gets away with a bigger nozzle because it don't have the third event, so you would want to size accordingly.

The 6.7's have multiple events, and have gone back to a similar bowl, so i don't think there will be a issue with late injection or duration.


I'll have a bit of a idea in a couple of weeks, I'm going to switch to the 03-04 nozzle with my monotherms and 04.5 ecm. They arn't exactly like the 03-04's but I'll get a idea of how they work and compare to the 124's.
 
I'm replacing my pyrometer with a clock -- something I can actually use.

I think autometer makes a nice one.

Post injection can't be helping this situation.
 
So is 1300 EGTS at 280 HP different than 1300 EGTS at 750 HP.
Other than cylinder pressure. Is that much more heat being absorbed into the oil & cooling system.
And then overload causing melted pistons?
 
jlibert said:
I'm replacing my pyrometer with a clock -- something I can actually use.

I think autometer makes a nice one.

Post injection can't be helping this situation.
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LMFAO, Now that is some funny $hit right there.:hehe::hehe:
 
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