The Diesel Conversion

[Chevrolet4x4s]

Does anyone know what is involved with swapping a 1996 6.5 N/A{(non computerized engine)that was put in place of a 6.2 in an 1985 Silverado}
into a 1973-1987 2wd chevy half ton originally equiped with a gas engine

[TankBulldog]

The swap will require a diesel torque converter and tranny update if selecting an automatic. Otherwise it is a matter of changing wiring to support the diesel fuel solenoid. Motor mounts for big block of that year will work. You may need to update your radiator for more volume, surface area should be okay. You will want to go to radio shack and get some indicator lights for glow plug operation and water in fuel separtator. Get a good wiring diagram and set aside some time. I put a turbo in a 72 suburban (previously had big block). I ran into cooling problems which necessitated updating fan, clutch and radiator.

[Chevrolet4x4s]

I have the water in fuel seperator and the engine from fan to flexplate and oilpan to air filter. You hook up the (gas) coil wire to the I/P dont you?Couldnt I just use a toggle switch for the glow plugs instead of having an indicator light.Did the gas trucks come with a fuel return line or would I have to run one?Would the gas fuel sending unit work or would I have to buy a diesel sending unit?What modifications would I have to make to the gas trucks wiring harness? Would a used aluminum racing radiator be a good choice?What about a NV4500 5 speed trans insted of an auto as I would like to run a 2.73-2.76 rear end ratio so that 70-75mph would be arount the optimal rpm range when in O/D and would still like to have decent (decent is used very loosely think so as to not get run over by a moped 2 blocks away:D )take off (6.51 first gear ratio)? What would be involved in going from auto to manual trans all I can think of is adding clutch master cylinder, slave cylinder and approiate lines,high hump trans tunnel,movie trans crossmember,diesel flywheel,will a gas clutch work,am I forgetting anything?Would I beable to get away with the gass brake booster and master cylinder or would I HAVE TO HAVE hydroboost.
I appologise for the lengthy post and not having it all in the first post but I ran out of time at lunch and didnt get to finish asking questions.

Also has anyone on here done this swap?Where would I get the wiring diagram that you mentioned would it be the one in my Hanes repair boog for GM (350,6.2,6.5) and ford diesels.
Thanks
Shane

[More Power]

A diesel engine doesn't generate vacuum like what a gas engine does with its throttle control. This is why the 6.2/6.5 need a vacuum pump to operate things like a wastegate actuator or EGR valve, or in the 80's trucks, the HVAC controls and cruise control.

There are examples of some European diesel automobiles using a vacuum pump to power a vacuum brake booster. A vacuum pump and accumulator might work with in a 6.2/6.5 powered truck/Sub, but a failure of the vacuum system would impact a safety item.

Jim

[JohnC]

I'd go with the hydro boost as most vacuum pumps are not intended to run a brake booster. The coil wire should work as long as it doesn't have a resistor in it.

If you've got a NV4500 with a deep low first gear, you'll find it's too low for normal driving. 3.42 gears gets you about 72 mph at 2000 RPM in OD. I wouldn't go lower than that as the gears in the trans get too far apart. If you're going to tow more than a couple thousand lbs, go with the 3.73 rear.

Carbureted vehicles did not have a fuel return line; you'll have to come up with one.

You can get a Ford starter relay and wire it to a momentary contact pushbutton for the glow plugs, but I'd still suggest an indicator light for diagnosatic purposes. Use temperature regulated plugs so you don't have to worry about burning them up.

[Chevrolet4x4s]

Ok so hydroboost is a must,Thanks

Mainly a commuter vehicle(college)not realy going to be used to haul/tow much wanted the high rearend ratio so that it would lope along in od on interstate and drop it down to 3rd or 4th for in town to and from school I'm shooting for 30+ mpg witkh possible 2.4/4 drop and tonnau cover and ram air

what size line would I need

Still have the controler and everything could I wire a toggle switch in so that they only come on at inital start up

Thanks
Shane

[JohnC]

I had a 2500 HD with the NV4500 and 3.42 gears. First was too low for normal driving. Second was OK for launches unloaded on moderate slopes. Starting out up big hills or with a load was a bear. If you have a lighter truck you might be able to get away with 3.21 (or whatever the next ratio is) but I would not go lower than that. Also, I'd look for a later trans with a less deep low gear, so maybe it would be of some use.

[Chevrolet4x4s]

I take it that the nv4500 and a diesels low end torque has a tendancy to roast the tirers in low :D What trans would you suggest? Is the nv4500 mechanical speedometer or electronic sender?
Thanks
Shane


PS: Would 30mpg (flatlands) be easiall obtainable if driven with a light foot ram air (or hoodscoop with open element airclaener)and a tonnau cover(mabe a spindle shackle hanger drop)

[Chevrolet4x4s]

OOOH YEAH forgot to ask would headers help my milage on a diedel(picked up about 3 on a gasser over the summer)
Thanks
Shane

[Chevrolet4x4s]

I was wrong on the ratio 5.61.....not 6.51:eek: oops
Shane