Re: Running a 50’s OMC in a barrel Home › Forum › Ask A Member › Running a 50’s OMC in a barrel › Re: Running a 50’s OMC in a barrel 1957evinrudeUS Member - 2 YearsReplies: 253Topics: 53 March 23, 2018 at 11:07 pm #72929 Learn something new everyday.I ran my 5.5 and 7.5 already in a small tank with no problems. I usually check the water coming out to see if its hot. If its running hot the water should be hot also.