The oilpan or, sump as I prefer to call it, requires some major surgery. I was hoping that I could cut the rims of both the Fiat and Niva sumps and use the Niva bottom with the Fiat rim. However as soon as I saw both engines side by side I realised this would not be possible as the two sumps are quite different in shape. With the engine block in the car I took some measurements using the boltholes in the bottom of the block where the sump bolts on as reference points. I then transferred these measurements onto the sump and marked out the initial cutting line.

I then cut along this line with an angle grinder. After several trial fits and some minor trimming I was able to fit the sump to the block and over the diff. This next picture shows just how much the diff intrudes into the sump.

After trial fitting the crankshaft I realized that there is not really a lot of room between the crankshaft counterweights and the diff housing. When patching up the hole I had to be real careful to follow the contours of the diff housing to ensure that the crankshaft wouldn't rub. Here are three more pictures taken before welding up the hole.



Once happy with all the clearances it was time to patch up the hole. I managed to do this with just two pieces of sheet metal. Initially I was quite happy with the end result, but after a few days I started to wonder if the sump had enough volume left i.e. oil capacity. I figured I had reduced the capacity by about 1 litre. Not wanting to run out of oil, especially when off-roading with the car on all sorts of weird angles, I decided to add a box to the sump to increase the capacity to at least as much as original. By the way, all welding on the sump was done with the sump firmly bolted to the block using all bolts to ensure it wouldn't warp. This is the end result.


I cut the drain plug out of the original piece of sump that I had cut out. On the inside I tried to put a as large a baffle as was possible to try and keep the oil from rushing back and forth when off-roading. Once painted the sump looked quite professional. I was pleased with myself as I thought the hardest part of doing the conversion was behind me now.