Implied Odds

Okay, let us imagine a scenario to hopefully illustrate my question.
You flop a four-flush on the flop against one opponent, there are then two checks on the flop and the turn card is dealt a blank. Here you will hit your flush card once out of just over 4 times (obviously) on the river, your opponent bets into you, lets say you are getting 3.5 to 1 odds to call, do you call? What about 3 to 1 pot odds? What about around 2.5 to 1 pot odds?
Let us assume that our opponent is either equal in chips or has us covered (so if we end up all-in we are doubling up if we have the winning hand), that if the flush hits we will win the hand (i.e we have highest flush and no full house/four-of-a-kind available), that we are only allowed to call/fold on the turn (we can't raise/raise all-in here), that we will not call a bet on the end regardless of pot odds if we miss, that you suspect our opponent is highly likely to put us/call all-in (he has trips/straight and you suspect us probably unable to lay it down) and that we are not on the bubble with a very small stack at the table and that we ourselves are not small stack/very big stack.

Essentially this was a long-winded way of saying to what extent do implied odds allow you to accept slightly unfavourable pot odds?

Hard to answer in a vacuum, it depends on a few factors:

- Is my draw to the nuts? (you already said there is no FH/quads possibility)
- Will my opponent stack off if I hit? It is very obvious to even unobservant players when the third flush card hits, if this happens will they just c/f, or perhaps make a blocking bet and fold to a shove?
- How big is the bet I have to call relative to my stack size? I guess this impacts the implied odds that I'm getting, but also because as your stack gets shorter each incremental chip you lose becomes more valuable.

Tai's answer is fine. To add to his point 2, you have better implied odds drawing to a straight than a flush, and better still if you have a gapper vs a connector - 9TJ is a scarier board than 8TJ. Better STILL if there was also a FD out, that missed.

I would read Theory of Poker and then head over to NLHT&P.

Raise the flop