Portal seekers have the information you want right here, but to summarize:
2 block portal conduits can go up to 2 blinksec and take 50 oort shards to open + 1 per minute,
3 block portals can go up to 4 blinksec and take 100 to open + 2 per minute,
4 block portals can go up to 7 blinksec and take 150 to open + 3 per minute,
etc.
Can also help with an in-game demo if this doesn’t help. Cheers
Edit: You can’t use a single piece of warp or portal conduit to open a portal, the minimum is a 2x1 or 1x2 configuration. Portals have to retain a rectangular shape of some kind as far as i’ve seen.
Think you mean horizontally as 2x1 are vertical. When in the ground tho it can be either. But as I’ve never tried doing them horizontally when looking straight ahead I don’t know if the work that way or not.
I thiiiink you can get horizontal portals, but it requires someone like @james to help you out.
There used to be some in the Legendville mall, but I can’t remember if the portals died naturally, or were removed because of server issues.