The three hours I allowed in my schedule turned out to be plenty of time.

The process of connecting Intl-Intl in T1 was:

- Long walk from UA gate to main T1 building
- Security re-screen in T1
- Collect boarding pass from airline transfer desk
- Long walk to LY flight gate

The walks were upwards of 10 minutes each at moderate stride. The wait in the security screening queue was 12 minutes.

BTW, El Al's article about checking in 3 hours in advance is rubbish for transfer passengers as their counter doesn't open until 2 hours before the flight to TLV and the gate --where transfer passengers must go through extra screening administered by the airline -- doesn't open until about 60 minutes before departure.