[Healeys] oil pressure problem

[healeymanjim at hansencc.net]

a while back i had mentioned a newly rebuilt bt7 engine that had very low oil pressure.  after doing all the obvious external investigations to no avail, we dropped the pan and tried to plastigage the rods.  here is where we discovered the problem.  the plastigage would not even flatten out.  i checked all big ends and they were all loose as a goose.  pulled all rod caps and discovered that even though crank stated it was .020 reground and mains were .020 undersize, all six rods had .010 bearings.  new bearings were installed and now  at operating temp the oil pressure is over 30 psi at about 1000 rpm.  all is well, right?  wrong.  we cannot figure out why even at high rpm we cannot get over 50psi pressure on a cold engine using two different guages.  we even put some washers behind a brand new relief valve and spring with no success.  the owner is going to live with it, but sure would be nice to know what is happening.  could it be a gallery leak we could not find or something i have never heard of.  would really like to know.