View Single Post
  #3  
Old 01-31-2019, 09:49 AM
v8volvo v8volvo is offline
Supporting Member
 
Join Date: Jun 2009
Location: Montana, USA
Vehicle: '86 745, '83 764
Posts: 1,618
Default

Sounds like a great project, keep the updates coming.

If you got the whole front subframe out of the diesel donor then it should give you everything you need to bolt the diesel right into the gas car. Hopefully the engine crossmember doesn't have structural rust. The crossmember from a 1989-1991 gas 740/940GLE with the 16 valve B234F engine also uses the same welded steel lower motor mount bracket on the driver's side that none of the other gas cars have so those can provide a replacement if needed.

The radiator idea is interesting, will be good to see how that turns out. It can be a challenge to keep these engines cool when they are working hard. The stock cooling system in the original diesel cars is just barely adequate when everything is in tip top condition with a brand new radiator. If you use a different rad it probably will need to be at least as large and efficient as the stock setup. But eliminating the long snaking lower radiator hose would be an improvement if you can get the in/out on the same side so will be good to hear what you find that works.

As ngoma mentioned you can also use a slightly different water pump from an early 1990s VW Eurovan with the 2.4L 5 cylinder diesel. On those the pump housing is the same but the pulley is slightly smaller so it spins the pump a little faster for more volume.

Head studs and a fresh gasket are a great upgrade to do at the start and will help it hold together when you turn it up.

In the 1991 gasser you will probably have the oddball Rex/Regina EFI system and its high pressure tank mounted fuel pump. Those deliver 60+ psi which is too much for the diesel injection pump. If you want to keep that pump you may need to install a bypass style regulator or put a tee to the return line to bring the pressure down, or install a low pressure tank lift pump instead from a car with Bosch FI. You could also swap in the simple diesel tank pickup without a lift pump but might need to get creative to make the fuel level sending unit compatible with the later gauge cluster.

Keep us posted on what changes are needed to the suspension to do the lift. I raised mine around 2.5" but didn't think it could go much higher than that without having to do major changes both front and rear to prevent popping the ball joints out at full droop and other geometry problems. I think for 4" you might need to space the entire front cradle down to lower the control arm pickup points and the steering rack, and maybe extend the trailing arms in the rear and build a drop bracket for the panhard bar. Solvable problems though and with a locker in the rear it'll go everywhere. Looking forward to seeing it come together.
Attached Images
File Type: jpg IMG_20170806_194120.jpg (192.2 KB, 15 views)
__________________
86 745 D24T/ZF 345k lifted 2.5"
83 764 D24T/M46 155k
Reply With Quote