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Is this true? I was reading that the VE produces quieter 4BTs because the timing is slightly retarded versus say a P7100.. Can anyone confirm this? If so strike one more for the VE 
Early 4BTs quieter because VE retards near idle?
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me neither but read it on Pirate yesterday....
Makes perfectly good sense. The VE pump has an advance mechanism that increases advance with RPM increase, the P7100 doesn't.Is this true? I was reading that the VE produces quieter 4BTs because the timing is slightly retarded versus say a P7100.. Can anyone confirm this? If so strike one more for the VE
Bob B.
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This would be correct for the Bosch VE pumps that were configured with the optional ALFB control. This control is designed to adjust the start of the fuel delivery to reflect load to reduce noise emissions with the primary aim of reducing exhaust emissions. If you have one on your pump you will find it located at the six o'clock position when facing the pump while looking at the side of the engine. It mounts in the location directly under the KSB. If you have a plate held on with two socket head screws in this location you do not have this feature on your pump.
REF: Bosch Distributor Type Diesel Fuel Injection Pumps, Oct 2003, pgs 46 & 47, "Control modules for distributor injection pumps-mechanical torque-control modules"
Bob,
All VE pumps also have another built in timing advance mechanism.
The timing is adjusted in response to engine RPM. At higher RPM s, the fuel pressure from the vane transfer pump is higher. Pressure changes effects a spring loaded plunger, and the resulting movement will move the cam rollers to either advance or retard the timing. What you are talking about varies the timing much more than the built in timing advance.
Bob B.
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So do P7100 pumps clearly not have this? A
P7100 pumps have no advance mechanism. The timing does not change from the initial setting throughout the complete rpm range of the pump. All VE pumps have an advance mechanism that advances timing with RPM increase, and retards it with RPM decrease.
Bob B.
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This is interesting...
And I thought the P7100 was the one to have?
Perhaps it is for drag racing or sled pulling where you are at wide open throttle all the time?
But for an everyday driver seems variable timing would be best?
What compromises do you have when running the P7100?
Can you have ideal timing at governed speed?
Or is timing retarded below ideal to allow the starter to crank it over?
Or am I missing something?
Grigg
And I thought the P7100 was the one to have?
Perhaps it is for drag racing or sled pulling where you are at wide open throttle all the time?
But for an everyday driver seems variable timing would be best?
What compromises do you have when running the P7100?
Can you have ideal timing at governed speed?
Or is timing retarded below ideal to allow the starter to crank it over?
Or am I missing something?
Grigg
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232 Posts
VE's cold start better
and they get better mileage. They take more heat in a vegetable oil conversion, and I think they are more delicate than a p-pump.
and they get better mileage. They take more heat in a vegetable oil conversion, and I think they are more delicate than a p-pump.
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Thanks! I'm stll figuring all this diesel stuff out :rasta:
PS. I sent you a PM :dustin:
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