Pump timing, how much more can I safely go!

[prototech]

I just advanced the timing 1/8" but it didn't make as much difference in power as I would have thought. I am wondering if when they put the pump in if they got the timing one tooth off to the retard side because it was all I could do to advance it 1/8". could the engine run if it was one tooth off? any thoughts? what are the tell-tale signs of advancing a pump too far or nearing too far? any insights would be welcomed

Proto

 

[dpuckett]

Too much advance will result in a higher pitched knock, instead of the clean, crisp, rattle of ideal timing. THe knock/ rattle will sound similar to a cold 6. 9 Ford, and gets more pronounced just off idle. It will also be slower off the line, may throw out some white smoke, and run higher EGTs after a point. Increases cylinder pressures, hence danger to head gasket integrity.



I see you have a 92. You can be safe with more advance from stock than the earlier trucks can. Try going another 1/16" and see what that gets ya. How much space is there between the top of the AFC housing and the head?



It is possible to get it to run with the pump gear being one tooth off, but it will smoke (white), chug, sputter, hack, gag, and cough. You might have to loosen the injector line retaining clamps to get the pump to move farther up. You DID loosen 4 nuts, right? (3 nuts and a bolt, actually)



Let us know how it works out.



Daniel

 

[prototech]

Yes, I got all of the nuts and bolts loose, however I only loosened the AFC banjo bolt so I was trying to twist the pump against that too. I think I have about 3/4" between the AFC housing and the manifold, I'll have to measure for sure. I might have another 1/16" I could go but it will put the bolts against the end of the slots, but I think I will try that!

Proto