Louis Of Chesapeake VA.

[Louis95]

Hello,
My name Is Louis. I recently picked up an 86 740 d24t. I have 3 other Gas 740s but have never touched a diesel. Goal is to put the drivetrain in a 1991 745 and lift it about 4" Thanks for the Add.

Louis

[v8volvo]

Welcome to the forum. Sounds like good plans all around. The diesel to gas swap has been done by a number of folks here and works out well. Your 1986 diesel donor is a good starting point since it will give you the updated style engine crossmember that is not prone to cracking as the 1982-1985 versions are, and a number of other small upgrades (plastic battery tray that won't rust away, etc). All the key parts will bolt in and most of the work is plug and play.

Converting into a turbo gasoline car is easiest since the battery and air inlet are on the correct sides. Using a NA gas car is more work because you need to relocate those, make various wiring changes, and switch the windshield wash bottle/pump/plumbing to the other side. On some NA gas cars with ABS the ABS unit is in the way of where the airbox needs to go on the passenger side so you are forced to use a non-stock air inlet and filter. The axle gearing is also usually more suitable on the turbo cars since some of the NA gassers had 4.10:1 gears, too short for the diesel. And in the later years (1990 on) many of the NA gas cars used Rex/Regina engine management which doesn't lend itself as well to converting the fuel system for diesel use. Regina fuel system has a single high pressure pump in the fuel tank so you need to either replace it with the diesel pickup (which removes the pump but may give the wrong signal output for your later year fuel gauge) or use an expensive standalone fuel pressure regulator with tank return to limit pressure to the ~10psi appropriate for feeding the diesel VE injection pump rather than the full EFI fuel rail pressure. The turbo gas cars and pre-1990 NA gassers with Bosch EFI instead have a low pressure lift pump in the tank that works well as a diesel lift pump for the IP, just remove and bypass the high pressure pump under the floor then swap wires around in the fusebox to run the tank pump when the key is on and no further changes are needed. In short, whatever time or money you might try to save by starting with a non-turbo gas car rather than a turbo you will end up wasting multiple times over to deal with conversion hassles where the turbo gas cars have the problems already solved for you.

In general it saves time to transfer as much as you can from the diesel donor car: you will need the driveline, trans crossmember, shift quadrant, fuel filler neck, glow system, battery tray and cables, and various electrical parts, exhaust, etc. A good set of Volvo greenbook wiring diagrams for both models and years of cars you are dealing with helps to make it straightforward. If you get all the details sorted out the end result can look and work like a stock vehicle and you get all the improved interior materials, electrical system etc found in the later models.

Having the engine out of the car is a good chance for a cooling system refresh, timing belt/water pump, and other service also. Unlike the gas Volvos a broken timing belt or a botched replacement attempt causes engine destruction on the diesels so you want to make sure it is fresh and do the job properly with the required special tools and procedure. All the info and tools are available to borrow for free.

Lifting 4" may present some challenges unless you plan to relocate the steering rack, suspension pickup points and move or lengthen the rear axle trailing arms, the geometry might not safely accommodate that much extra height without some effort. But you can add 2-2.5" lift on the stock setup with taller strut housings and spacers/longer shocks in the rear and no major surgery. Looking forward to seeing how it turns out. Keep us posted on how it goes and ask questions anytime you have them, many folks here will be able to share experience or special tools/service info when you need it.

[Louis95]

Thanks for the reply and all that info. Sadly it's going into an N/A shell but the engine bay is bare so shouldn't be hard. Biggest thing for me is getting the tach to work. I'm just waiting on studs and HG now as far as parts go tho.

[19misha72]

ОЧЕНЬ ХОРОШИЙ И ОТЛИЧНЫЙ ОТВЕТ ! ДИЗЕЛЬ d24 ЛУЧШЕ И ХОДИТ 500000 километров.