Pump Timing

[rdodd]

The pump shop that advanced my timing used a timing light and set timing at 12*. I think they called it dynamic timing. Which type of timing is more accurate? Would 12* be the same as 1. 5 lift?

 

[paccool]

Not sure how they can use a light. Wonder where they get the trigger from? Some of you pump experts know what the heck this is about? Never heard of a light being used on a diesel like ours.

 

[BushWakr - RIP]

This method uses a "fuel line pulse detector" on #1 Cyl.

Each time the line pulsed delivering fuel it sent an pulse. This is used to trigger a timing light.



I watched this used at PDR on my truck.



Regards, Bob

 

[paccool]

Thanks Bob.

Well, I learned something today! Just never heard of anyone using a light before. Bet those baby's aren't cheap!



Stan

 

[rdodd]

Most of the stuff iv'e read here about pump timing says set at 1. 4 to 1. 5. So what would mine be set at if its 12* ?

 

[BushWakr - RIP]

Here we go with the MM and Degree thing again



I found out that 1. 5mm is approx 15*

If I remember right 12* is approx 1. 25mm or there abouts. Actually, Piers or Joe D, or maybe PW, will have a more accurate conversion. I asked Piers if he could email me the conversion or whatever for this but nothing yet.



Regards, Bob

 

[Power Wagon]

Sorry, no luck here. Cummins may have some kind of conversion in their engineering section, but since I have never had the time to play on the test stand to check rotation degrees vs lift, I'm a bit out of the loop on this one.



Perhaps when I get my pump on the test stand, I can make some sort of crude testing, but that's going to be some time in the future.



Just for the record, VE pumps on Cummins B engines are timed anywhere from 2. 1 to 1. 2. Many naturally aspirated engines are up closer to 2. The noise with the stock injectors at that point is very harsh, but the bigger injectors seem to dull it a bit.

 

[CToney]

It is sometimes called flow timing. They have a sending unit that goes on the #1 injector line that hooks up to a timing light and they use marks on the vibration dampener the same as on a gas motor. You have to make marks on the vib dampener that you would see in the light. The diesel shop that timed my truck did it this way too. I think 1. 5mm is supposed to be about 14-15 degrees. Hope this helps as to which one is more accurate I'm not sure.



CR Toney

 

[BushWakr - RIP]

Right on CToney !!

Al at PDR said mine was set at about 1. 45-1. 5MM which is 15*.

'Course at my age, I can't remember my darn address...



Regards, Bob