tooth jump

ozone burner

ozone burner

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Mar 18, 2009
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when skipping a tooth on the pump gear to advance timing witch way do you turn it clockwise or counterclockwise
 
i have never heard of jumping teeth on the VE pumps to advance timing......
 
I haven't messed with a ve pump before, but normal rotation of any cummins injection pump would be clockwise looking at it from the front of the truck.
 
If it has the same number of teeth as a ppump gear, then one tooth jump would be 5 degrees at the pump or 10 degrees at the crank.
 
It is the same tooth count as on the newer 12v's. We have letters on the pump gear rather than a single mark. You want to turn the gear clockwise to advance it.
 
Now someone just needs to sit down and figure out how many degrees the slots are worth on the VE.

Someday I may get to it.
 
people swear each tooth is 10* since there are 72 teeth on the pump gear and each 1mm of pump rotation is 1* of timing.
 
Well what do they say the pump pushed to the head is worth timing wise? Thats prob how much timing one tooth is because u jump one tooth then pull it to stock marks and that is equal to one am i thinking right or not.
 
JBradley500 said:
E and O are stock

C and O are 1 tooth advanced
Click to expand...

This is advanced two (2) teeth.

CamIPIndexing.jpg




ozone burner said:
Well what do they say the pump pushed to the head is worth timing wise? Thats prob how much timing one tooth is because u jump one tooth then pull it to stock marks and that is equal to one am i thinking right or not.
Click to expand...
Advancing things 2 teeth allows you to have 1 toofe's (shoved to the head?) advance and keep the IP pretty much at the stock marks or close the the center of the adjustment slots of the bolts. That way, you can get to the back of the IP (between it and the head) if you need to. ;)
 
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Advancing things 2 teeth allows you to have 1 toofe's (shoved to the head?) advance and keep the IP pretty much at the stock marks or close the the center of the adjustment slots of the bolts.
Click to expand...

So by advancing 2 teeth, you've bumped static timing up by 20°, to about 32.5° advance?

--Eric
 
Im not stealing BC847's answer but here's where i found someone elses explanation of the 10*.


"72 teeth on the pump timing gear, at half the crank speed is the equivalent of 36 teeth, (72/2). 36 teeth, mulitplied by 10° = 360°, or one revolution."
 
one thing id like to know is how close timing relates from a VE pump to a P-Pump. I mean if the VE is more of a low pressure spray wouldnt you need more timing than a p-pump in most cases? im not really good at this stuff but it seems like less pressure would have a slower spray (less pressure with the same orifice sizes) and less fine of a spray which both require more time to properly get into the bowl and totally burn. IDK but ive been wondering this the past couple of days.
 
ENafziger said:
So by advancing 2 teeth, you've bumped static timing up by 20°, to about 32.5° advance?
Click to expand...

I've advanced the IP gear two teeth and have the IP at about the stock timing marks.

- The last time I checked the IP timing as per the FSM method (IP piston lift @ TDC), it was around 2.8mm lift. Stock is 1.4 (such is not to suggest I'm running double the factory injection event timing as the cam-plate's ramp isn't linear).

I have no clue what it is in terms of crankshaft degrees. :bang It's a lot though.


EDIT: That cam-plate ramp not being linear may be what makes ciphering injection event timing difficult.
 
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A lot of pullers run over 30 deg of timing with big injectors.....it would be interesitng to put a timing light on the truck at 2 teeth advanced and see where it was at.
 
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