Pot Odds? Changed for this particular game?

Ok, I'm just grasping the whole idea of pot odds and the odds on your outs. E.G -- you work out your 4 to 1 against to make your flush, you want at least 4 to 1 on your money. Ok, seems simple... just that you have to work it out in the heat of battle.

BUT I play at a local game where it's usually about 6 handed. We play that you can put down as much as you like, with the minimum of £50. There is 1 blind to the left of the dealer and this can be anything from £1 to £10, whatever the individual desires. The big bet on any round is £10, and it is capped after 3 raises, just like in a limit game.

Now say there has been tremendous betting before the flop, making a pot of say £100. The flop hits, and you flop a gutshot straightdraw, 4 cards to make my hand, to make the nuts. That puts me at about a 16% chance to hit it, or 11.7-1 against. The bet to me is now £10 with 2 callers ahead of me. That's a pot total of £130... I'm getting 13-1 pot odds, should i call? And also call down the river for any bet providing no flush draw has it or the board paired?

Also, what if there was only one bettor and the 2 callers this time folded. What is the bet was £8?

Any advice... Cheers. I just want to know if i'd end up making too many stupid calls because of pot odds? With this amount of raising pre-flop one would assume it to be a loose-aggressive game.