School me on diesel fuel systems

[Mrk1]

Im more them comfortable work on gas engines but never had a change to play with diesels. I know the concept but not the details. I am very interested in doing a 6.2 swap but Im researching how a 6.2 would work in a rover, keeping it as simple and reliable as possible.

Anyone care to give me some explanations or point me in the direction of some info.

Im not scared of sounding like a newby,

does an electrical pump feed the mechanical?
what is this I hear about check valves in the fuel system?
does the fuel return like on some gas engines?

 

[LtFuzz]

Are you asking about how to put the 6.2 in a Rover?

Or how diesel engines work compared to gas engines?

 

[Mrk1]

How diesels work compared to gas, the conversion is nuts and bolts

 

[aka rover]

Of all the choices why a 6.2? please tell.

 

[Mrk1]

simplicity of a non turbo, available, plenty of parts in the US, good power/mileage

 

[aka rover]

What is the mileage of one of these motors ?

 

[Antichrist]

On a diesel the injection pump sends the fuel to the injectors which inject it in the cylinders, either directly (direct injection) or in to pre-combustion chambers (indirect injection). Diesel engines have very high compression so the fuel/air mixture auto-ignites, no spark needed.
Some diesels (most automotive) use glow plugs to preheat the combustion chamber when the engine it cold. Others use a preheater in the intake to heat the intake air.
Fuel gets from the tank either by an electric pump or a mechanical pump, just like with petrol engines.
Yes diesel uses a fuel return line to return excess fuel to the tank.
Diesel engines require the fuel system between the filter and injectors to be free from air, so you don't want to run out of fuel, otherwise it will require extensive cranking, and/or priming the system.
Diesel starters have very high current draw (the small Land Rover 300Tdi starter can draw well in excess of 300amps) so you need a good battery and heavy starter cables.
Fuel cleanliness is very important, so you need a top notch fuel filter. They generally aren't cheap.
Untreated, diesel fuel will gel in cold temperatures.

 

[BillTex]

Untreated, diesel fuel will gel in cold temperatures.

Sounds good...except for the gelling in cold weather. At least in the US, diesel is blended for winter...just like gas.
There usually is no need for additives of any type.(Maybe we need to define "cold"?)

Use good filters, and keep a spare with you at all times. Our Duramax has been as cold as -30 deg F and has always started fine...I don't even use a block heater.
Maybe in much colder climates a block heater would be a good idea...in New England we have never needed it with direct injection.

 

[LtFuzz]

What is the mileage of one of these motors ?

mil surplus J-codes are guaranteed to have less than 50k mi, in some cases much less than that even

 

[I Leak Oil]

The electric pump is considered a lift pump which supplies relatively low pressure fuel to the injection pump. The lift pump can be mechanical as well, similar to a gas engine diaphram fuel pump. Think of the injection pump as a distributor on a gas motor. It's timed to the motor to inject high pressure fuel into the cylinder at just the right part of the compression stroke. The high compression of the motor causes the fuel\air mixture to get hot enough to ignite. The excess fuel is returned to the tank similar to a gas fuel injection system.

Clean, dry fuel is important in much the same way as a gas motor. Some diesels are more tolerant of moisture. In cold weather moisture is a real bummer.

 

[tacr2man]

Just going to poke a tiger but! You need to think what you want to end up with as a 6.2 in a rover is right at the physical size limit and can need further mods to make it a reliable vehicle, trans and suspension etc . The 6.2 is a "truck" engine and makes the vehicle overly front heavy in MHO , its a lot of effort for not that great a result . I can see its appeal in the USA comparative to what else you might have available to use in its place tho, it would not be my first choice , and I have modded a few landies over the years , but each to their own .

 

[David Harris]

Just going to poke a tiger but! You need to think what you want to end up with as a 6.2 in a rover is right at the physical size limit and can need further mods to make it a reliable vehicle, trans and suspension etc . The 6.2 is a "truck" engine and makes the vehicle overly front heavy in MHO , its a lot of effort for not that great a result . I can see its appeal in the USA comparative to what else you might have available to use in its place tho, it would not be my first choice , and I have modded a few landies over the years , but each to their own .

As far as front heavy goes, if you calculate it, a 6.2 in a Disco gives about a 50/50 balance. I agree it is a lot of effort for not much gain, considering you get more weight, less power and nearly the same mileage as a Rover 4.6, which just bolts in.

I used to be of the swapping mind, until I looked hard at the effort and figures involved and decided to stick to the Rover V8, which I think is a great engine when properly built and maintained.

 

[LtFuzz]

Just going to poke a tiger but! You need to think what you want to end up with as a 6.2 in a rover is right at the physical size limit and can need further mods to make it a reliable vehicle, trans and suspension etc . The 6.2 is a "truck" engine and makes the vehicle overly front heavy in MHO , its a lot of effort for not that great a result . I can see its appeal in the USA comparative to what else you might have available to use in its place tho, it would not be my first choice , and I have modded a few landies over the years , but each to their own .

A truck engine? It's a medium duty and the same weight as the majority of other medium duty diesels (Isuzu, Dodge, et al).

less power and nearly the same mileage as a Rover 4.6,

What? I can get 400-430 miles on ~21 gallons of diesel.

That is not going to happen in a 4.6.

 

[Mrk1]

edit:double post

 

[Mrk1]

These are just the responses I have been looking for. Also Ive been doing more reading myself.

As far as the weight thing goes Im not concerned. My truck is a Series 3 body on top of a RRC frame so I figure I can pick up a few pounds before getting close to the weight of a regular RRC. I also want to do it just for the challenge. I worked at an independent Land Rover shop for a while and am not a huge fan of the Buick derived engines. What I love about my truck is how simple it is so a chance to drop in an engine that needs so little to run is great to me. This truck is my rebellion against the ridiculously over complicated cars coming out today.

With 35's and 4.75 gears I will be more then happy with 15mpg.