Rolling Coal

[karlsmith]

Yes, it's a Hillrod move, not intending on debating that here. What would it take to make our machines do this? Turbo, electronic fuel pump? Drawbacks, obvious and not obvious? There is no law in my state against it, however my searches have found that it is against the Clean Air Act (CAA).

 

[mdainsd]

Its against federal emissions standards and equally or more importantly why would anyone want to call even more attention to our vehicles? It makes it harder on everyone when jackwads do stupid things.

 

[Skrilex]

It takes years off. Even an old man can appear to be an idiot kid if rolling coal. That being said it happens when more fuel is delivered than can be burned. I would imagine injecting fuel pre turbo into the exhaust stream would do it too

 

[mogger7]

just wasting fuel

 

[Action]

Would the return lines not handle extra fuel delivered to injectors?

 

[Tow4]

Because sometimes, you just have to....

 

[98G]

Restricting air should have the same effect as delivering excess fuel. Partially occlude the air filter.

I can't imagine why anyone would want to do this. Half the people who witness it will think "what an idiot!".... The other half will think "we need more laws!".... Neither is a reaction that I want to provoke...

 

[patracy]

It takes years off. Even an old man can appear to be an idiot kid if rolling coal. That being said it happens when more fuel is delivered than can be burned. I would imagine injecting fuel pre turbo into the exhaust stream would do it too

That'd be a bad idea for a few reasons.

 

[Augi]

When I go to the mountains above about 6k or 7k ft of elevation I notice that my truck starts to blow dark smoke when I put my foot into the throttle (ie ascending a steep mountain road) where at lower elevations it wouldn't. The higher I go, the less throttle I can give it before it starts doing it. Not quite "rolling coal" as seen on TV, but a lesser version of the same phenomenon and still very noticeable. I just let off a little when I see it and it clears up. The extra throttle isn't moving me any faster and the EGT's start to shoot up.

This happens because the air is thinner at altitude so the mixture is richer at a given throttle input. Diesel engines operate by controlling the fuel side of the air/fuel mixture. The air side is whatever you get in the intake. At different altitudes and temperatures the mass of air in a given volume changes and so for the same amount of throttle, the mixture is different. This is the problem turbochargers were originally designed to address. They reduce the variability in the air density before the fuel is mixed.

Anyway, enough of that science stuff. The bottom line is you can make any diesel "roll coal" if you want to. You will run into two bottlenecks at some point: Either the injection pump or the injectors may not be large enough to deliver the extra fuel required to do what you are looking for.

Drawbacks:
- You may do some damage to your engine. The EGT's can get hot enough to burn valves and do other damage. Fuel washing down the cylinder walls is bad for the rings.
- You are messing up the environment.
- You will definitely look like an a-hole.


Augi

 

[big block 88]

Block the air intake about 90%. It will run like ****....

black smoke = HIGH!!!!!! EGT's. High EGT = substantially shorter engine life and possible melt down.

Here hoping she melts to the ground for you before you bring more negative views on this hobby if you are doing this on purpose...

 

[dhaumann69166]

Rollin coal is caused when you are dumping more fuel than you can burn. Easiest way to get this from a 6.2 diesel is to turn your injection pump up a little excessive and drive it like you stole it. 90% of fuel overload “rollin coal” happens at low RPM under a load. The bottom end of each gear with 3/4 or more throttle will get your best smoke. There will be negative effects from this. It’s going to be really hard on your motor and tranny. You won’t be able to roll smoke for a block like you can in a Cummins due to the fact the Humvee raps up so quick. Expect 2 to 3 seconds of smoke per gear.

 

[dhaumann69166]

Also expect the 6.2 to fail very shortly then you can go to a Cummins or Duramax and spend 30,000 or so to blow a little smoke and burn up another motor.

 

[98G]

d. I would imagine injecting fuel pre turbo into the exhaust stream would do it too

Diesels equipped with DPF do exactly that in order to regen the particulate filter. Temperatures inside the exhaust system of 1400* and above are frequently seen.

I can think of a lot of bad things this would do for components not designed for it. (In fact, the list of badness for those vehicles designed for it is a long one...)

 

[tage]

Wow, took 11 posts for someone to actually know how to do it.
That and the whack ball ideas of improperly how to do it.

Key word with this thread.... Is egt. Too high you'll melt a piston, and then you pay to play.


Last thought. Turn up your injection pump until it blows huge clouds, hit it with some NOS, and a water/menthol injection.
Thank me later

 

[tage]

Diesels equipped with DPF do exactly that in order to regen the particulate filter. Temperatures inside the exhaust system of 1400* and above are frequently seen.

I can think of a lot of bad things this would do for components not designed for it. (In fact, the list of badness for those vehicles designed for it is a long one...)

Have to burn up the soot somehow. Modern diesels produce very little soot on stock maps.

 

[big block 88]

Modern DPF inject raw fuel post turbo fyi.


Also rolling coal with a 6.2 is a whack ball idea in itself. You think the 6.2 will survive a water/meth and n20 spray? Maybe a 50 shot tops. More than that you will end up with the elusive see through engine block option.

The 6.2 was and never will be a performer. The old detroits were made to run a long time at stock power levels and deliver better economy than the equivalent gasser of the time.

You want power step into DI engine or better yet a CR.

 

[Broke Down]

Cut the tips off your injectors with a hacksaw, it will belch it out. Or, turn your fuel up and have a heavy foot.

 

[Skrilex]

Turning up pump isn’t really how you’d do this because you couldn’t turn it off. My limited knowledge of this idiotic practice is that it’s intense smoke just momentarily. Normally achieved with special maps on electronic injection. Choking the air might work maybe. But when people say it will ruin the engine what exactly is it that the engines don’t like about it? If it’s temporary and not while towing up a mountain I don’t see why it would really hurt anything inside the truck, rather just the environment outside the truck.

 

[karlsmith]

Here hoping she melts to the ground for you before you bring more negative views on this hobby if you are doing this on purpose...

Yes, I am doing this thread on purpose. What does that even mean? I started it by stating that I wasn't doing it for debate, just for understanding how it could be done and the drawbacks. I'm one of the few guys driving a diesel around my family and circle of friends, so I get asked this question. I couldn't find any youtube videos with one of our machines doing it, even with the H1 guys that trick everything out. Nothing hit on the forum search either. I appreciate the responses, but did get a kick out of the "idiot kids" with a F350 rolling it over a Prius in some of the videos I found.

 

[Recovry4x4]

I would have no problem with anyone rolling coal as long as it came out the cab windows. Actually it would be entertaining to watch. If you piped your exhaust into the cab, you could grade your success as you tried all these wonderful ideas.

"So preoccupied with wether or not they could and didn't stop to think if they should" Ian Malcolm.