I am building a 1983 300SD for 1 mile LSR racing...just beginning the project...i cannot find a spec for the min and (more importantly) the max pressure at the injector pump inlet??? does anyone have any experiences they would like to share of replacement lift pump options?

In Liberty,with Velocity

Dave

Increasing the lift pump pressure won't do any good. First there is a pressure relief valve on the back of the IP in the return line banjo bolt. This will limit the pressure. Second, Diesel is incompressible so your not going to force anymore fuel into the plungers and thus injectors by increasing the lift pressure.

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For Sale: 1982 MB 300TD
1995 Chevrolet Suburban 6.5TD

Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel

Even though we call them "lift" pumps they should actually be called "transfer" pumps. They work on flow not pressure.

The injection pump is really a compressor with timed release valves (the line outlets).

Transfer pumps generally deliver X amount of fuel at less than 5 psi. As was pointed out in the previous post, any excess pressure is vented into the return line.

You can increase the pressure from the pump with internal adjustment which of course means you have to change the nozzles and readjust them or you could just have the pump and nozzles caliberated to each other. For peak ultimate performance that is the way to go.

14psi is the relief valve pressure.

I thought there was some talk on superturbodiesel.com about 12V cummins guys getting some gains from adjusting the spring in the bypass valve.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

This works also for the Benzes. Some old style valves can be disassembled and the spring length can be increased (30mm is a good value) to provide complete filling of the elements.
The larger elements have an increased (and funnel like) bore compared to the originals so there must be some possible gains.
Using vo or even wvo sometimes when the temperature is not reached the fuel supply is not sufficient and in this case increased pressure in the gallery of the ip helps (either from the lift pump or from the tweaked by pass valve or both).

Tom

So what kind of flow rate would one be looking for in an electric pump?

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My Primary Driver - '85 300CD - 4-speed conversion, 2.47 rear, lowered, euro headlights, rebuilding (not restoring so much)

Wife's - '08 Saab Sportcombi Aero

Riding a '03 Yamaha Warrior

Why would you want to use an electric pump when the mechanical pump is more than adequate?

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Just playing around with ideas. Do know what the spec would be?

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My Primary Driver - '85 300CD - 4-speed conversion, 2.47 rear, lowered, euro headlights, rebuilding (not restoring so much)

Wife's - '08 Saab Sportcombi Aero

Riding a '03 Yamaha Warrior

welll... an electric pump would allow you to prime the system without ruining the starter..

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As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

A lift pump from a Dodge with a Cummins would work more than well enough.

On the VE pump TDIs people noticed more low end torque and more top and HP when using a transfer pump to help the IP.

-Jason

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Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
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