Why are the tips on the new 6.4L so weird looking, they have perforation that seem designed to suck air in, is it some sort of emission thing.

 

its to try and cool the tip down during the regeneration process. Plus it makes a good flame thrower on the earlier models...

 

You are correct, that is to mix cool air with the super heated exhaust after the DPF goes through a regeneration cycle.

 

should just let them catch on fire

 

the ones on the newer d-maxs are kind of like that too...same reason?

 

That made me laugh... I have seen the flame throwers...

 

maybe they're not working so good:


Shortly after Ford introduced its revised 2008 Super Duty, more than 37,000 F-250, F-350, and F-450 pickups with 6.4-liter Power Stroke diesel V8s were voluntarily recalled after reports and a video documented three cases of flames shooting out the tailpipes, like a blow torch.

The problem didn't help Ford’s strained relationship with engine supplier Navistar. Within days of the recall announcement a video of one of the trucks spitting fire surfaced on YouTube, giving the world a dramatic look at how serious the safety risk was.

The cause of the problem was traced to uncontrolled amounts of diesel fuel leaking into the diesel particulate filter, where high temperatures in the soot trap ignited the fluid. Super cold starts (in temperatures as low as minus 30-degrees-F) had cracked turbo seals in two of the trucks. The third had a temporary obstruction in a fuel injector.

 

I suppose the main purpose of it is to reduce the temperature of the last section of pipe, that way people don't get burned and/or have something fall against the pipe and catch fire (like in a garage). Regen cycles get pretty hot and likewise raise the pipe temperatures really high too, a lot higher than you would see on a non-DPF equipped truck.

 

And they got a new fancy name for them now. You cant call it a "tip" or a "turn out" or a "stack" anymore. They're called "defusers" now!

For real, thats what they are technically called. As far as the temperatures on a DPF equipped truck, I have personally monitored and noted the pipe coming out of the DPF having a temperature of 1700 degrees! Thats the temperature of the outside surface of the pipe! This is only during a regeneration cycle though.

 

What do you search for on You tube to find the video of the flame? I searched a little bit and couldn't find it

 

Are riggin supervisor has a 6.4L and last winter was so cold -55* Celcius he let the truck idle over night 1400rpm. we cam out the next morning and there was ATF and coolant ever where. I guess they had a recall and ever since then its bin good.

 

http://www.youtube.com/watch?v=45Mp1BPTV7A


Looks like a good way to cook ricers.

 

Actually there was another video of a 6.7l Dodge doing same thing. They had issues on their own too.

 

The same very reason. That is way if you get the correct aftermarket "DPF" back exhaust kit, it too has some sort of cooling provision designed in.

 

The air inlets are to cool the actual exhaust gases not so much the tip itself. I've heard the exhaust exiting the DPF can be as high as 1100 deg. This doesn't have much of a chance to cool in the pipe before exiting. The inlets mix the outside air to cool it to the point where things won't combust, including your pant leg when you're loading stuff up.