How do you get bigger chest for gym workout?

roids.

What you need to do is hit it less often, but with more intensity. I am an ectomorph, but that is not a bad thing because it means we both have very little fat and any muscle gains we make willb e highly visible. I Recommend you go to bodybuilding.com, they have great info. But to quickly say, 4 times a week is way too much, I hit chest once a week really hard by itself and get great results. Since it is all I'm doing, I will do a ton of bench presses, incline, decline, flyes, pullovers. I will then do a set of pushups till failure. There is no way you can do this with maximum intensity if you workout 4 times a week. Like I said go to bodybuilding.com, here is a page with lots of chest articles to get you started. http://www.bodybuilding.com/fun/bbinfo.php?page=Chest

bench press

Concentrate on dumbells (flys) 3 sets if you can do a super set the better. Do not forget dumbell pull down. I got the same problem I started worked out about 8 years ago, only last year I notice changes, when a gym instructer taught me how. 4 days a week may or may not be too much for as long as you have interval, for your muscles to rest. You may use supplements such as creatin or amino acids. But still the best way is to have you monitor by your gym instructor and to check if your gym program is ok.