On the cylinder bank of 4.0 engine v 8 which is designated as number cylinder?

In a V8 engine with a cylinder bank designation, the cylinders are typically numbered sequentially, but the specific numbering scheme can vary slightly depending on the manufacturer. There's no single universally accepted standard. However, a common arrangement is:

* One bank might be cylinders 1, 3, 5, and 7.

* The other bank would be cylinders 2, 4, 6, and 8.

Therefore, there isn't a single "designated number cylinder" for a bank of four in a V8. The bank itself contains cylinders with numbers 1, 3, 5, and 7 (in one common numbering system) or 2, 4, 6, and 8 (in the other bank). You would need to consult the engine's specific documentation (owner's manual, service manual) to be certain of the numbering scheme for that particular engine.