Hello all,

I posted a while ago about really yearning for a 242, and a rolling shell 1979 has come up for sale not too far away from me. I currently have a running 1990 740t w/ m46 tranny in the garage that I paid not much money for, and am toying with the idea of pulling the engine and tranny out of it and sending the remainder to the wreckers.

My question is, what kind of fitment issues am I going to have with this swap? The 242 includes a drive shaft, am I going to need to find a m47 to work that in? Is the rad + intercooler + fan shroud fitment going to fight back? And the motor mount location going to need the subframe from the 740?

Plus the hundreds of other things that I'm not thinking of right now. Some feedback would be awesome.

Thanks,
Nathan

 

Answered one of my own questions already, the '90 740t and the '79 240 GT both came factory with the m46, according to this (seemingly exhaustive) list:

Volvo Transmission Page

 

Fairly straight forward... Tranny is easy, just the driveshaft may be different length, the engine size is the same, turbo and all; just the management system (ECU) has to be swapped.

 

The engines are basically the same except for they moved several things around for the 740 vs. the 240. All of the accessories (alternator, power steering pump, air conditioner) were located differently on the 740 vs. the 240. Also, on the 740 they moved the distributor to the rear of the head - which won't fit in a 240 (no space back there).

To swap over is easy if you had all of the components from the 240. But since you don't have the 240 accessories (I assume rolling chassis means no engine), you will have to pull them from a junkyard. Make sure you get all the brackets for them. Relocating the distributor may be tricky as I'm not sure that the half-shaft on a 740T would have the gear to run the side mounted distributor.

 

It's optional whether you move the accessories from 740 configuration to 240 configuration...will work either way. You WILL have to swap the intermediate shaft from the 240 motor into the 740 motor as the latter has no drive gear for the block mounted distributor. It is VERY straight forward. It's the same block so just use 240 mounts and brackets. The additional thickness of the intercooler means the n/a fan shroud will not fit...you have three options. Score a proper shortened shroud from an intercooled 240 (getting scarce), use the 740 fan shroud w/ mechanical fan clutch, use the 740 fan shroud with an electric fan. The swap has been done 100's of times; you are not breaking new ground here...
The real issue is you are going to need to swap in the LH2.4 wiring complete from the donor. To do so neatly, you will want to swap out both firewall panels as well as the grommets and holes are quite different. As for drive shafts, the rear portion has always remained the same; at most, you need only swap the front, short portion.