So, I finally got my car fixed with a good used block. All of the sudden, I am seeing engine blocks popping up for cheap around my area. I thought I would pick up an extra one and build it as a spare just in case. The guy doing my machine work knows a lot about rovers, and told me that the Gems 4.0 block has much better quality control than the bosch 4.0 and 4.6. I did some research and the only difference i was able to find was that a sensor mount is different, but can be tack welded to fix the issue, and that the knock sensor position is straight rather than angled? Anyhow, I found a good gems block for $100, and was going to build another 4.6 out of it as a spare for my disco. Will the crank, rods, and pistons fit without any modification? I know that the bosch 4.0 has no problem accepting the 4.6 crank,rods,and pistons; wondering if the gems is the same.

thanks for any help.

 

yes, those parts will fit in just fine in any 4.0l (but not a 3.9 or 4.2)

the part number for the crank sensor mount is probably EIQ100020 (I just saw this on another forum).

 

THanks Jafir. Thats what i thought. I'm going to go ahead and pick it up tomorrow.

 

Oh, and thanks for that #

 

The 4.0 engines that were molded in the 97 thru 99 were made from a better quality alloy.
If you are going to build an engine, consider running a set of opened up 4.2 heads, they will give you better performance.

 

Mike, Is that true of the 4.0l blocks in both the '99 D1 and the '99 D2?

 

No, only up to the early production 99 D1's. BMW tried to save some money and it cost the rest of us some good engines blocks.

 

Good info to know. Thanks Mike!

 

so do these older blocks have the same head gasket problems?

 

I think they all have hg problems!!

Now, i picked up the engine today, and I have it on the stand. everything looks different and I am skeptical right now to think that i can convert this to a 4.6 and use it as a spare for my 03.There are a few differences I noticed right off the bat.

-First off, the oil pan is different. On the 03, the oil pan lines up with the bell housing, and IIRC bolts to the tranny. Not on this gems 4.0! Do i use the 4.6 pan on this? I have a spare so no problem there if possible

-knock sensors are completely different: On the 03, there is a stud that the sensor goes onto and a nut holds it in place; on this 4.0, there is a sensor that looks a lot like a temp sensor. I tried plugging a spare knock sensor from my 03 into the wiring harness from the 4.0 and it did not accept it. What to do?

I havn't been able to pull too much apart yet, but I will probably have the whole thing apart tomorrow; hopefully these are the only things other than the cps sensor. I'll also try to get some pictures up for comparison.