Common Rail Cummins - How much timing?

[shawn]

Our Dodge, for all intents and purposes, is basically stock under the hood. Stock turbo, bigger elbow from the HE351, 4in downpipe and exhaust, boost elbow, pyro, boost, and a Smarty SR. That's pretty much it.

It's been set on level "5" pretty much since I bought the Smarty. 7 makes too much smoke, so I generally don't use it. The truck pulls pretty well, but gets hot pretty quick on hills. On any decent grade, you pretty much have to drive it by the pyro.

Level 5 adds "some" timing over stock, but last weekend, I tried bumping it up to the next level. I have no idea how much more timing it adds, but it definitely starts to rattle.

It made a huge difference in EGT, though. It'll still get warm, but not nearly like the default settings.

So, my question is... how much timing is "too much" for long-term durability? I figure the biggest risk is due to the increased cylinder pressure, but at only ~25psi, is lifting the HG really a concern?

 

[Ron]

@vbaughcome

Wanna weigh in?
Come on give us the Cummins factory response...

 

[Croatan_Kid]

EDIT: Now that I'm home from work and have a few minutes, I can actually respond a little better. Granted, my truck has a VE pump, but I didn't get all wild with my timing and it's been a trooper. Injectors, cam, some pump work, a few small mods, and a 62mm turbo are letting me see 56lbs and it takes it like a champ. Then again, as you mentioned, I've had plenty of other people tell me they've had head gaskets let go at 35-40 lbs. 9 times out of 10, their timing was advanced a full tooth (or two) on the injection pump. Mine had a small twist of the injection pump and that's it. My EGTs are in control too, surprisingly.

With that being said, I have no idea what kind of timing a common rail sees, but I wouldn't think it would be so much that it would bust a gasket at only 25 lbs. From what I've been reading (which isn't a whole lot, just a few articles) you can electronically add up to 9 degrees of timing and stock is something like 15.5*.

 

[Hurley]

@shawn

If you're hearing the timing rattle, you are getting close to what Kenny Loggins describes as "The Danger Zone."

With your modifications, I would honestly not worry about running it above level-5. From what I've seen online, CR people often get overzealous with the settings and end up with a melted piston or two. I wouldn't be the least bit concerned with the head gasket, though.

~In before the "get the UDC tuning software"~

(I'm just a forum junkie, so most of my knowledge is regurgitated from other people's experiences on other forums)