I have 4 cylinder, a 6 cylinder, and a V8 now it's time for a V12.
I purchased a 750i awhile back for $500 running driving. when I puled the engine out, I found the bell housing very large. There is also the oil pump and sump to be move to the rear.
Recently I have found 3 MB V12 in the self serve junk yards and 2 more BMW's. A MB V12 was purchased for $400 complete.
The MB V12 oil sump look's like a better fit, and the bell housing is small. Problems are over all hight, rear exhaust manifolds and no flywheel for manual. The auto flex plate has a bolt on ring gear with the cut out windows for the crank sensor's and a thick clamp ring on the crank. So the stock ring gear and fly wheel bolt's will work for a custom FW. Clutch size is 10.5".
The bell housing is cut off the front of the auto trans just behine the ring for the pump. One side of a plate was turned down to fit tight in the pump ring bore, With the same set up on the lathe the hole for the T5 was bored.The bolt pattern for the pump was transfered to the plate, drilled and counter sunk for Flat head scoket screws. The plate is mounted to the bell housing and machined parallel to the engine side. Factors that make up the lenght of the bell housing are ring gear clutch and piolit bearing. This means a long input shaft lenght. Looked for a ZXt T5 never found one to check out. If you have a ZX with a T5 and rear steering this swap might be a winter project. Found a T45 (the 5 speed version of a T56) it is big and 125 Lbs. Ended up with a T5 at 75 Lbs. from a Mustang 3.8 V6. A Hyd. cluch release bearing from a Camero T5. A Mustang clutch.
I am starting work on the cross member now. Clearnce for the Miata Power steering at the side of the oil pan has to be worked out before I can finnish it.
Next will be shorting the oil sump, moving the left throdle body foward and the exhaust.
Last is finding a EFI to run it.
When all the Junk Yards are in alinement with the Swap Meets I will have a Rat Rod