For what it's worth, I'm an electrical engineer. Actually, I'm a professor of such. College professors don't have the same sort of schedule as industrial folks so my experience is perhaps atypical of many engineers. I have the time to run and still do other things (my wife and I kayak half the year, hike, and xc ski in the winter). Don't have any kids though. That's a serious time impact. I will say that I wasn't able to juggle running into the mix while I was a student and had to quit XC as a freshman. It was just too much for me, and well, I was there primarily to get a degree and not to run. Thus, I became a recreational runner through those years and the remainder of my 20's (as I spent most of my time working on my career). Now in my 40's, I look back wondering how far I could have taken my running if I was able to stick with the competitive side, but at the same time knowing that if I hadn't focused on my studies and early career, I most likely would be in a less favorable position now. At the same, I find that as things stabilized in my 30's, I was able to return to competitive running (at least at the local level). In spite of being past my physiological peak, I can still train hard, push myself, and try to set PRs as a master.
I think the real question you have to ask yourself is how much you like engineering and the things/rewards it brings versus what running brings you. This is a serious question with long-term implications. You don't want to just chuck a promising and otherwise enjoyable career out the window because you fear that it might not allow you to run as much as you'd prefer. The portrait of the "starving artist" might play well to the romantic in us, but no one finds living off of Ramen noodles a particularly attractive lifestyle.