LanceD

my truck is stock with the plate moved forward and straight piped, no other mods, does advancing the timing improve power? if so, what do you advance it to? Where can I find a step by step on the net for this? Also, when I get a TST plate, Governor spring kit and injectors, will I want to advance it more?

thanks!
Lance

infidel

Advancing the timing will...

Decrease exhaust temperature (more useable hp)
Increase cylinder temperatures/pressures
Increase fuel economy
Increase your output of NOx (a pollutant)
Decrease your output of Hydrocarbons (a pollutant)
Increase the amount of black smoke at peak torque

Raising the cylinder temperatures/pressures after already having increased the fueling (as a plate does) pushes the engine that much closer to its design limits, but lowering the exhaust temperature helps balance against the increased heat load from the increased fueling.

15.5 - 16° seems to do the best for a 12 valve.

Instructions here http://dodgeram.info/tsb/1994/18-10-94a.htm

Timing chart here http://www.piersdiesel.com/TechPTiming.htm


Some folks aiming to save money advance the timing with timing tape on the dampener marked out in degrees. The problem I see with this is you must assume the timing is set correctly to begin with. About half of the trucks I've reset the stock timing on have been low, some as much as 3°. Setting timing any other way besides the plunger lift method is therefore a guessing game.
For most folks it's cheaper to have a shop set the timing rather than buy the tools to do it themselves. Problem is finding a shop that will do it since it's against pollution laws to alter the timing from the factory specs.

Haulin_in_Dixie

Infidel correct me if I am wrong, but advancing the timing ignites the fuel sooner, which leaves a longer duration for the flame front before the exhaust opens. This effectively reduces smoke. That is what had to be done on the Detroits when putting larger injectors to control smoke.

infidel

Dixie, I'm not sure how it all works but at 1000 rpm, black smoke will decrease with advanced timing, at peak rpm/ max torque load it will increase, and at the rated 1800- 2200 rpm it will decrease.
This is the reason Cummins went with variable electronic timing on 24 valves to control emissions.
With 12s we're stuck with one setting though (glad we are, simple is better!)

LanceD

where do you buy those tools at and how much are they? will I ever use them again after setting it?

PourinDiesel

All of the high horsepower pulling trucks that run high rpm have their timing set crazy advanced.

Maybe somebody will care to speculate openly on how much??

--Justin

J.R. Adkins

Nope

PourinDiesel

Thats sort of what I thought.

infidel

Some of the guys sled pulling are running their timing over 30°, once you get over 20° the engine gets hard to start.

Timing tools here http://buy1.snapon.com/catalog/pro_d...re&dir=catalog

The Snap-On kit is about the same price you'll find anywhere. Most people will probably only need to use it once, not worth it.

LanceD

thats cool, I might get that, I get a 28 % discount from snap on being in the military.

infidel

Lance, the price Snap-On lists on their website is the very highest they charge. Along with your discount you'll get a much lower price.
You are also going to need what's called a barring tool to rotate the engine. Not sure if Snap-On has one but Cummins does, around $30.

Thanks for serving!

LanceD

sweet thanks! btw do you have a part number for that barring tool?

infidel

Lance a search found these-
Cummins # 3377371; Snap On # YA9565; KD tools # 3824

LanceD

So will I notice an increase in useable power?

infidel

Yes, you will be able to keep your foot into it longer before the egts climb too high. This assumes that you are adding more fuel though modifications (plate) that the egts were getting high before the timing was changed.