Bigblock SIDI?....

[Gareth]

Yeah, have come across that sump difference before - wreckers sending us HY7 engines from VE (rear sump) that we fitted to VZ (front sump)

We have a dead VZ HY7 out the back, I'll get the young bloke to pull the sump off, hopefully same bolt pattern.

As for the trans bolt up, possibly need to change bell housing on our 4 speed??? to a VZ one

[vlad01]

id be more interested in seeing what the LFX engine looks like. fuel system and the piston oil jets intrigue me.

[monaro308]

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Some info courtesy of GM and interweb
High Pressure Fuel Pump
The high fuel pressure necessary for direct injection is supplied by the high pressure fuel pump. The pump is mounted on the rear of the engine and is driven by a three-lobe cam on the Bank 2 exhaust camshaft. This pump also regulates the fuel pressure using an actuator in the form of an internal solenoid-controlled valve. In order to keep the engine running efficiently under all operating conditions, the engine control module (ECM) requests pressure ranging from 2 to 15 MPa (290 to 2176 psi), depending on engine speed and load. Output drivers in the ECM provide the pump control circuit with a 12 V pulse-width modulated (PWM) signal, which regulates fuel pressure by closing and opening the control valve at specific times during pump strokes. This effectively regulates the portion of each pump stroke that is delivered to the fuel rail. When the control solenoid is NOT powered, the pump operates at maximum flow rate. In the event of pump control failure, the high pressure system is protected by a relief valve in the pump that prevents the pressure from exceeding 17.5 MPa (2538 psi).

Fuel Rail Assembly
The fuel rail assembly attaches to each cylinder head. The fuel rail distributes high pressure fuel to the fuel injectors. The fuel rail assembly consists of the following components:
The fuel injection system is a high pressure, direct injection, returnless on-demand design. The fuel injectors are mounted in the cylinder head beneath the intake ports and spray fuel directly into the combustion chamber. Direct injection requires high fuel pressure due to the fuel injector's location in the combustion chamber. Fuel pressure must be higher than compression pressure requiring a high pressure fuel pump. The fuel injectors also require more electrical power due to the high fuel pressure. The ECM supplies a separate high voltage supply circuit and a high voltage control circuit for each fuel injector. The injector high voltage supply circuit and the high voltage control circuit are both controlled by the ECM. The ECM energizes each fuel injector by grounding the control circuit. The ECM controls each fuel injector with 65 V. This is controlled by a boost capacitor in the ECM. During the 65 V boost phase, the capacitor is discharged through an injector, allowing for initial injector opening. The injector is then held open with 12 V.

The fuel injector assembly is an inside opening electrical magnetic injector. The injector has six precision machined holes that generate a cone shaped oval spray pattern. The fuel injector has a slim extended tip in order to allow a sufficient cooling jacket in the cylinder head.

The LFX engine is very similar to the LFW; an LFX may be generally thought of as a “big-bore” LFW. Changes between the LFW and LFX consist mostly of slightly different valve sizes and a longer-stroke fuel pump configuration to provide the additional fuel for the larger displacement. Of course service parts and assemblies between the LFW and LFX are unique and RPO-specific service procedures must be followed, but there is a strong overall similarity between the LFW and LFX.

The oil passage that supplies oil to the main bearings also supplies oil to pressure-actuated piston-cooling oil jets. Each oil jet is mounted between opposing cylinder bores and directs oil to the 2 bores to provide extra cooling and control piston temperatures.

[vlad01]

great bit of info there! thanks for posting it.

[Jayme]

sounds like getting high hp out of these could be tricky.... high pressure cam driven fuel pump and specialised direct injection injectors... could be hard finding bigger versions of either....

I wonder how close to max duty cycle the injectors are standard.... given its direct injection on a 4 stroke, around 25% overall duty would be firing for the equivalent of the entire intake stroke... just under 50 % and youd be injecting fuel for the entire intake and compression strokes... tho I also have no idea when in the cycle they start injecting... could be they inject right before the end of the compression stroke, which sounds likely as they say in the above info that the fuel pressure needs to exceed compression pressure.

[Gareth]

It seems that the mechanics of this set up are very fine tuned, as for after market parts, this is a world wide engine - surely some one will be messing with it now. I never thought I'd see the day when people 'hotrod' diesel engines (all the rage in europe). Possibly not much to improve on inside the engine - turbo and/or specific fuel tuning is where the improvements are???

as far as a replacement power plant for an older vehicle, Im having trouble coming up with negetives.

[Circlotron]

I wonder how close to max duty cycle the injectors are standard....

Maybe at a pinch you could add port fuel injection to supply the extra amount needed. Most of the time these extra injectors would sit dormant.