Canadian24v

What timing are people using with larger injectors? Using a timing light I found that my stock timing was 5 deg with the ksb unplugged, 12 with it plugged in. Moved the pump to the head and was then at 8.4 deg/15.4 deg. Checked timing on my roomates '90 Non IC and was 12.3 deg with the ksb on or off no change. Stock pump gear is lined up c to e. Moved it ahead a tooth so c and c lined up. 72 teeth on gear, 720 deg of rotation (two crank turns for one pump turn) So each tooth is worth 10 deg. NEW timing is 18.5/25.5. Boost and egt prior to tooth change was 34 psi and 1300F after peaks were 22 psi and 1000F. Obviously timing is too far advanced. I'm thinking 13-15 might be ideal and just leave the ksb off. I think pump timing range was 0.65mm to 2.25mm? and now is 1.65mm to 3.25mm? Any input would help.

wannadiesel

I have no idea. Mine is timed by ear/trial and error. 18.5 base timing isn't bad for your setup. If it sounds spooky or runs bad, back it down a little.

The KSB does more to keep the case pressure up under load than it does for timing. You will have that same advance at high RPM as long as the case pressure doesn't drop) whether the KSB is on or off. The KSB just advances the timing at low RPM as a side effect of the added case pressure.

sdstriper

You check the pump plunger lift timing with the dial indicator adapter that screws into the back of the I/P. Also from the alignment marks on the pump flange and gear housing, One mm (.039inch) of rotation past the timing mark will advance or retard the pump timing by one degree.

Canadian24v

I have the dial indiator but it's faster to just hook up the pulse adapter and check.

19.2 deg = 19 psi
15.4 deg = 24 psi
14.5 deg = 27 psi
12.8 deg = 30 psi
10.1 deg = 31 psi

I completed these within 30 mins so air and engine temp remained consistent.
I moved back to 11.9 deg after this.

The VE pump does advance unlike the P7100. 18.5 deg would work well if it did not advance. Running the truck at 19.2 deg egt's were really low-600F at 120 Km/hr. great bottom end but to much advance for the top end. Does anybody know the total advance the VE pump has off of base timing?

apwatson50

I don't know how much the piston advances past base, but I would expect that with the ksb on it just about maxes it out. An easy way to check would be to remove the spring under the ksb then reinstall the valve and see what the timing is.

I had 2mm milled off the retarded side of my advance piston, and I just installed the pump with the gear advanced one tooth. So we'll see how it runs in about a week.

Canadian24v

apwatson that sounds like a good idea. I think if i did that I could run more timing without affecting the end of the injection as much. Post your results I'm interested to see how it works out.

wannadiesel

AFAIK it has 8 degrees of total advance.

Canadian24v

Thank you for that info. I was guessing 7 deg because of what the ksb was doing. I guess my total timing should be 19.9 deg. Off idle it ran great with 19.2 deg but the advance was to far in the top end. runs real good now at 11.9 deg.