Timing p7100 with a cut cam

Tycollins37

Tycollins37
I was going to bring the timing back down a few degrees on this truck using the dial indicator type. The timing is different for the different hp pumps going by lift. Im wondering how to calculate my timing with this ground cam thats different than stock.
 
Do you know what the pumps pinned timed at? If so just start with the pump pin timed, then remove the gear and set the engine to tdc, then mark the balancer and advance or retard the engine from that point using your balancer as a reference.

Diameter of balancer divided by 360 to know how much to move it from your tdc setting. Much easier and more accurate way of doing it.
 
I see you want to retard the timing a couple of degrees, just bring the pump pin in the window, it will stay there even without the timing pin in. Then you can knock the gear loose without fear of the pump being under tension and moving on its own. Then roll the balancer clockwise about a 1/4" and should be close to 2*.
 
Talking to the guy that built the pump now im not sure if the cam is even cut but the tag on the side of the pump is gone so im not sure what hp it is. I would like to map it out if any one knows the process
 
Once the spill port is covered is when the injection event begins (there is a delay, but we won't concern ourselves with that), install the dial indicator and note its reading. Turn the pump counter clockwise until you are on the base circle. Note that as well. This is zero lift of the plunger. Bring it back to were port closure happens. If you installed the pump at this point, it would have 0 degrees advance or retard. With your degree wheel, advance it half or one degree at a time, and record the plunger lift. Do this for as many increments as you desire. Keep in mind that rotation to plunger lift will not necessarily be linear, it will slow down and stop towards the top of the cam, but unless you're running a lot of timing or its a really aggressive profile, you likely won't run into this.
 
Back
Top