Hey guys
Just wondering why would you advance your timing 17 degrees in a 12 valve diesel what are the pro's and con's? is there a how to on it?
thanks for your help. i did a search but did not find the answer i was looking for.
Thanks Eric

 

Timing advance depends on the model of pump you are running too. Most of the earlier pumps could handle 17° pretty well, I only went with 16° on mine.

Advancing the timing will...

Decrease exhaust temperature
Increase cylinder temperatures/pressures
Increase fuel economy (yes, economy is better)
Increase your output of NOx (a pollutant)
Decrease your output of Hydrocarbons (a pollutant)
Increase the amount of black smoke at peak torque


I got this from dodgeram.org..

 

Basically, more timing moves your powerband up higher. Thats why you see sled pullers running 30+ degrees timing. Takes away some bottom end and takes a bit longer to spool up the charger.

 

The P7100 pump in your 12 valve truck has static timing as opposed to the dynamic timing of the older VE and newer VP44 pumps. Those pumps advance the timing as rpm climbs where the P7100 does not. Because of this it's a good idea to advance the timing to the point where it's most efficient at the rpm where you spend most of your time, usually highway cruise rpms. This is typically from 15 to 17 degrees of advance. Note that this is NOT increasing the timing by x number of degrees, it is increasing the timing to x number of degrees.

It's also worth noting that the amount of timing advance that Dodge spec'd in the 12 valves is intentionally less than in other applications of the Cummins B series in order to reduce NOx (nitrogen oxide) emissions.

 

Wow thanks for the response guys!
Is there a how to on this project?
and is this something i should do for a daily driver

 

This is definitely worth doing on a daily driver (in my opinion anyhow). There's a couple of different ways to do it, but I think both involve some specialized tools. I've never had a P-pumped 12 valve, and being much more familiar with the VE and VP44 pumps I'd probably take it to a diesel shop and ask them to set the timing to 16 degrees.

 

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

Problem is you need about $200 worth of specialized tools to do the job correctly.
For most folks it's cheaper to have someone else do the timing.
Just make sure they follow the above instructions, not the guesstimate method.

It will pay for itself in better mpgs setting the timing to 16* plus you'll get more power too.

 

So my local diesel shop wants 360.00 to advance my timing. Is it worth that much, and what type of mileage increase are we talking about? How much bottom end does it take away? I have 33" tires on 3.55's and just went to a 5" turbo back, and that seemed to take some bottom end away too. I don't want it to be a pig on the bottom.

 

Keep shopping, you can get all the tools to do it for less than that.

 

Dealer says it's a 3.1 hour job to change the timing.
Haven't been to the dealer for a long time, are they charging over $100/hr?
Not that it matters, the dealer and Cummins will only set your timing to stock.

 

It's not a dealer shop. It's a place called Santa Rosa Diesel, and they charge 120.00 per hr. That seems to be the rate her in good old Nor Cal!

 

If they are using the the timing pin, should take maybe an hour and a half.

 

Do it yourself! It's a 1-2 hour job at most and you can re-sell the tools for almost what you paid for them if you want. I have 3 rigs and the timing tools have been used a bunch since I "discovered" what the 12 valve is capable of after I bought the 98. It really is an amazing engine, even by todays standards of the "digital world." You can keep the new stuff, it can't compete with this old proven mechanical "contraction." Hope this helps, cd

 

Will this kit work?

http://www.puredieselpower.com/catal...t-p-28753.html

 

Yep, but here is info I got when I first got here, how to do it even cheaper, enjoy!

Well, You can get a delivery valve socket from piers diesel for $30.
2. For the dial indicator, Harbor Freight sells them for $10, and it works just as good as an expensive one. It has been used ot the forum more than once. The only prob. with it is it is in inches. That isnt a big deal, because if you search on DTR people have converted the mm to in. measuremens.
3. For a dial indicator holder, you can use a drain plug from our cummins. I went to autozone and they had one for $5.00. You just drill out the center so the dial indicator slides in there. Then you need to drill and tap a small hole for a set screw in the side of the drain plug, so the indicator doesnt move.
4. For the gear puller, any cheap steering wheel puller will work. You can get them from auto parts stores, for under $20.

I did mine this way and it worked out great. I looked on ebay and came across a metric dial indicator for cheap, after I did it with the inch dial indicator.

There you go, under $70.