Quote:
Originally Posted by diesel_john
roflwaffle, correct me if i'm wrong, you obviously know a lot more about pumps. how much timing advance is too much? when EGT's drop? On the mechanical system should i raise the internal bypass pressure?
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Well, I've read a lot about pumps at least.
You can kinda sorta set it via pump pressure and flow rate,
but it isn't super accurate. The main idea though is that wear and thinner fuels almost certainly retard dynamic timing, so increasing internal pump pressure is better than nothing. On a slightly related note, this is also why people with VE pumps on biodiesel may see better or the same mileage even though biodiesel has less energy per gallon. With a more viscous fuel, the advance mechanism works closer to stock spec. Ideally if you can check timing you can compare a change in that to mileage, but even w/o checking it you can still make small changes and see if anything improves, using the normal timing to fine tune.
I don't know if anyone has measured changes in IP pressure to EGTs, but it should help, along with excessive clattering, in determining if you have too much advance.