Mr. shrapnel;
Thanks for the laugh!

You'd think I'd learn to put a plastic guard on the keyboard before I log on here, eh?

Very nice looking truck by the way.

All the best to you and yours this Fourth of July weekend.
Dwayne

Dwayne I'm running a 4 door Allison Chevy D-Max Dual wheeled flatbed hauling tidy tanks saws ect.Typical brush truck.It's mileage is horrible.Rather drive my 2000 5.3 vortex for fuel mileage.

Been bombing around in it since hunting season.

prince brothers towing here in town have a 99 dodge duelly cummins that runs 10.38 in the quarter mile at a 128 mph. he does most of the cummins mods around here for peaple.he drives that monster around town with two big slicks on the back

After market?



What is a lift pump?

Mr. Barkoff;
In a diesel engine, if the fuel tank is below the engine, as it is in a truck, it requires a mechanical or electric fuel pump to take the fuel from the tank to the high pressure pump. Typically these are low pressure units not too dissimilar to the fuel pump that would be in a gas motor equipped vehicle.

The pressure pump operates at very high pressure, as in several thousand psi to atomize the diesel as it is shot out of the injector into the cylinder head. They are almost always mechanically driven and typically are mounted on the side of the engine block.

Hopefully that explanation made some sense.

Happy Fourth of July to you and yours.

Dwayne

Thank you, so I guess the high pressure unit will increase HP?

Mr. Barkoff;
Generally when one speaks of "dialing up" the pump on a diesel one is increasing the volume of fuel delivered, not the pressure exactly. The orofices on the injectors will have a given range of pressure and volume at which they will operate, so when one "dials up" the pump past a given point the injectors will need to be changed.

Newer pumps are computer controlled, so the adjustment isn't mechanical any longer but changed electronically. The injectors still will need to be changed out if one wants to "chip" the engine beyond what they are capable of delivering.

As with gas motors, one needs to start to modify air intake, exhaust and valve timing as well if we really want to step on things. Because diesels operate at much higher compression than a gas motor, one needs to modify the crank, the head bolts and such as well if one is pushing the envelope such as the 138mph 1/4 mile truck mentioned earlier.

Sorry for the sketchy overview, I've likely forgotten to mention something major, so if I've ommitted something, I stand to be corrected.

Dwayne

Mr. Barkoff;
OK forgot this, if we chip or dial up the volume on the high pressure pump, we need to ensure it doesn't run out of fuel.

That's why we then add higher flow lift pumps- to ensure the pressure pump gets all it can use.

I've likely forgotten a bunch of other stuff too, sorry.

Dwayne

They for sure decrease your bank account if you have to have one replaced and you are away from home like I was when it happened .

2500 bucks EXCHANGE for a REBUILT one installed .Actually , that did include a new lift pump now that I think about it .

I think the old mechanical pumps are the most desired and easiest to "dial up" my dually gets 22 mpg freeway
check out this cummins
http://www.youtube.com/watch?v=-x4Dkx0J8Nc&feature=related