my truck will be at cummins next week for a repair(see help section) and i am considering having them check/adjust the pump timing if i can still afford to(again, see help section) i asked them briefly over the phone and they said that it isnt going to take them very long if they do it. what should i have them set it at? truck is a 97 12 valve with just a tst #11. boost usually peaks at about 32-33 psi. i have a ''free - flow'' exhaust. 3.55 rear end. my egts are always in the ''safe '' range and i dont often tow heavy loads. i guess that im just trying to make sure its set where it should be and that im getting my max available power for my setup without having to worry about o-ringed heads, shortened engine life, etc.

 

Chances are they will set your timing to factory specs. If you look in front of the pump you should see a tag that has a "CPL" number on it. That is the number they will look up to find out what it should be set at. Go here to see what they will set it at:
http://www.piersdiesel.com/TechPTiming.htm .
Tom

 

Tom is right, by emissions laws Cummins will only set your timing to the specs on the CPL plate instead of setting it at 16.5° for maximum power and fuel economy,
You most likely will have to have someone else bump the timing up but it sure won't hurt to ask.

 

well, i understand your point about the emmissions law. but, if i have it adjusted somewhere would 16.5 be the optimum setting for what i need?

 

16.5 is the best in my opinion. Some folks go higher for even more power but then hard starting can become an issue.

 

I have mine at 16.5* and I sure like it. I can't seem to get the pyrometer over 1100* except when I am at WOT and 35psi boost.
Tom

 

Advancing timing is a popular and easy way to pep up a diesel by making it act and respond silmilar to a gas engine. It however places greater strain and pressure on the bottom end. This effectively shortens the life of a diesel engine between overhauls. I suggest reading this website before making any timing advancements. http://www.dieselinjection.net/frames.html
They build everyday driver high HP diesels and retard timing to retain engine durability. I particularly like the OTR Cummins N14 with 1,000 HP output.

 

ok- i thought that i was set in asking them to set the timing to 16.5. after reading this link, i realized that this shop says ''do not advance the timing in a cummins engine''. which is right? it would allow my setup to make more power--right? is there a risk or concern about realistically shortening my engines life--or setting me up for a failure?

 

No problem whatsoever with engine longevity advancing the timing to 16.5°. In fact it will probably increase engine life. This is what the 12 valve B5.9 is set to when it doesn't have to meet EPA emissions requirements in export and non-motor vehicle applications.

 

mines set at 17* and I like it I would bet most guys on here have bumped up there timming around 16-17 and I don't hear about engines failing prematurely on here from it. I would have to agree with the EPA just trying to set their own standards as usual. \
remember gassers are considered beyond mechanical limits over 100,000 but ctds are just getting started. my dad has 97 3500 cc auto CTD with 450,000 with no problems and he has pulled some big loads in the mountains of CALifornia
good luck