New engine questions

[rtarh2o]

I am new to the 6.2 diesel. I just bought a military take-out and am in the process of installing it into my 94 Toyota Land Cruiser. I have a couple questions. In the photo below there are some arrows. One is to a tube running along the front of the engine. It goes up under the intake and exits towards the rear of the engine, what is this? Next are the two wires towards the rear of the passenger side head, and third is the arrow pointing to the large nut with and electrical connection on top of the coolant tube. There are also 2 threaded fittings above the oil filter on the other side of the block, I have seen pictures and these seem to go to an oil cooler, is this an engine oil cooler? If so do I need a separate cooler besides the transmission cooler? These engines seem very simple, just never seen one before! Can't wait to get familiar with it.
Thanks in advance for the information, any other insight into what I need to do for the conversion would be appreciated.
Rusty

[DmaxMaverick]

Sometimes it's hard to tell, depending on the application it came from. I'll take a stab at it.

The lines at the front/right of the engine (looking from the flywheel forward) are fuel lines. The larger goes over the engine from the tank to the mechanical fuel lift pump, or filter inline on the way to the LP (not installed on your engine). It will be similar to the standard SBC pump. The smaller line goes to the IP, or to a filter, then to the IP, depending on application and Y/M. Ideally, you should have a primary fuel filter (10-30 micron) before the pump, and a secondary filter (2-10 micron) between the lift pump and IP. The filter assy's should be heated below 40°F. Lots of options, look to the aftermarket for commercial type filters. Racor, CAT, etc. They're all good. The filter assy's that use industry standard elements are best. Usually cheaper and more readily available.

The electrical connectors at the right/rear are likely temp sender and FSO/HPCA connectors. Hard to tell, but they are somewhere. If you follow the harness(es), they should lead to the source.

The fittings at the left/rear are for the oil cooler. It must have one, independent of anything else. Omitting the oil cooler will spell certain demise. Normally, the lines run across/behind the radiator (on civi models, between the fan and radiator) to a tank in the cold (RH) side of the radiator. If your radiator doesn't have an oil cooler, use a plate type cooler, like for an auto tranny. The infamous "leaky oil cooler lines" will be what you need. There are non-leaky options, as well as homemade setups. No rules here, just make sure the oil is plumbed to a cooler and back.

The "large nut with electrical connector" at the top of the engine is a temp sensor in the coolant crossover. Depending on the configuration, could be for the GP controller or HPCA, or both. The sensors have migrated around the engine over the years, and according to application. If it's a switch, it will be for HPCA and/or GP control. If it's a variable sender, it will be for the gage. Some had a sensor with both sender and switch, and had 2 or 3 spade connectors. Depends much on how you intend to wire it up. The best option for a conversion is to replace all the senders according to how you wire it in your vehicle. Gage sender should be at the rear head area. GP control sender can be omitted, depending on how your intend to control the GP's. The HPCA sender is necessary for reliable cold starts. If you intend to control the HPCA and GP's manually, the senders are not necessary, leaving only one for the gage. Your choice, and lots of options depending on your intentions.

[rtarh2o]

Is the mechanical lift pump a fuel pump? I was planning on adding an electric pump inline, would this serve the same purpose?
Where does the lift pump go? ? As you can see in the pictures, I am missing quite a few things and having never seen one of these engines I am at a bit of a loss!

[DmaxMaverick]

Yes. Mechanical fuel lift pump. It will go into the hole at the RH/lower area where those hard lines are, exactly like a small/big block Chevy. I highly recommend a mechanical lift pump over electric on a mechanical IP engine.
For many reasons:
No need for a failsafe. The mechanical pump will only move fuel while the engine is turning. An electric will require a failsafe to prevent fuel pumping if the engine stops, like during a traffic collision. Not incorporating a failsafe is irresponsible, unsafe, and illegal;
No need for additional wiring;
Cheaper (much!);
More reliable;
More effective. It will pump fuel volume according to engine RPM. An electric has a fixed output volume.

An electric does make filter/system priming much easier. Nothing wrong with having both, as long as the mechanical is the only pump running while on the road. Proper system prime/purge will minimize this downfall with only a mechanical. You may hear from both sides of the mechanical/electric argument, but I'm still waiting for dispute of the facts.

[ccatlett1984]

i agree with using the mechanical pump on the mech. engine.