Is is possible that the name is Michael Whealan, as the name healan is not registered as such.
Found a baptism record for John Whealan born in the Diocese of DUBLIN , Parish of ST. AUDOEN'S R.C.
Baptism of JOHN WHEALAN of N/R on 27 December 1796
Father : Michael Whealan
Mother : Mary
Sponsors : MARY BURRISS and JAMES LEE
Michaels age would have been 36 around this date
No records of Michael or his family after this date in Dublin, more then likely because the went to the USA
A Patrick (W)Healan was the godfather/sponsor of baby John Lonergan dd.21 September 1837 Diocese of DUBLIN , Parish of ST. JAMES'S R.C.
babies parents were : Michael Lonergan and Sarah Hewson