Eqqman said:
You're correct that you have to move fast, but it is easily doable to build the Forge early enough to prevent the spawning of the first Great Prophet. The Oracle is finished in 1680 BC, the Forge in 1600 BC and the Great Engineer appears in 950 BC, a turn or two ahead of the Great Prophet. The only chance of the Great Prophet is if you get nervous and finish the Oracle too soon. 1680 BC might be pushing it for the Oracle on Monarch and above, I'm not sure what the average Prince times are for the AIs. Because the window for preventing the Prophet is so slim, I wouldn't recommend starting the Metal Casting - Pyramids plan unless you already know how you're going to pull the whole thing off. The only thing that should ever come as a surprise is the AI beating you to one of the Wonders.
did you play this or is it just calculation?
the first great people takes only 100 GPP.
even if (through chopping and whipping) you manage to get the forge out in the 2nd turn after the oracle and then put an engineer into it, you'll have:
8 GPP prophet flavour before the forge is built,
then 4 prophet and 6 engineer GPP/turn for 10 turns.
meaning 52 prophet points
and 60 engineer points.
For me, it's far from sure to get an engineer.
Unless you build the oracle or the forge somewhere else?
in this situation, you have 16 turns to wait for the GE, while the other city has 4 GPP/turn = 25 turns. So you need to build a forge in less than 9 turns in a distinct city. Doable, true.
Meaning you could have the mids some 24 turns after the oracle, if you didn't forget to research the techs
OK, worth a try. What you need is a high food second city though, and the ability to whip hard.
If you build the pyramids in the forge city, you'll end up with only engineer, since the prophet points won't catch up. You then could have a second engineer 20 turns later. just in time to build the hanging gardens and give yourself another push towards engineers

Next GE can build yourself the national epic in the GE factory, to be sure you only get those

After a while you could build the hagia sophia there too = you used all those engineers to build useless wonders in order to get more GE
Edit : malekithe gave me the explanation i missed, and was faster than me

I leave my post because of the follow through GE generation thing