I need a new motor for my 92 740 turbo. Will there be an issue with dropping in a motor from a 94 non-turbo 940 while still using my current turbo charger. As an example will I be able to use my turbo exhaust manifold on the 940 motor?

 

Yes, there will be issues. I'm not sure about the location of sensors but the non-turbo engine had a higher compression ratio than the turbo. Additionally, I think the turbo has uses different exhaust valves to handle the higher heat. Also I think that there is no oriface in the block of the non-turbo for connecting the oil lines.

You might check out TurboBricks | High Performance Volvo Club for more info on this kind of swap.

 

In theory, the only hold up is the lack of an oil return present in the block for the turbo. This can be dealt with by placing a hole in the side of the oil pan and using high temp silicone hose and AN fittings. The stellite coated sodium infused exhaust valves could either be harvested from the old head or just ignored. Lots of folks have run n/a valves on turbo motors. The higher compression of the n/a motors mean you will need to be gentle with the boost...3-4 psi until you find where it begins to detonate. Les boost on a higher compression motor equates to more boost on a lower compression motor so it isn't as if you will be losing power. N/A motors generally have not been flogged as much as their turbo brothers. By 94, I believe both turbo and n/a motors had built in piston oilers to keep the pistons cooler. Certainly the turbos did, the n/a at worst will have the bosses built in to accept squirters. Small issues, not insurmountable, but need to be addressed. Ast Act has mentioned, TB has a ton of write ups on the swap.