mjr46

Never once has a engine builder I know ever recommended 20w 50 for a fresh motor, nor have I ever said to do such for any of the motors I have built for people, as a general rule of thumb bearing clearance should be .0015 to .002 per inch of journal.....if you have to use 20w50 to build any sort of pressure, you got excessive clearance and need to find a new machinest.

palerider

+1. Only time I ever heard anyone useing that thick was if car needed a rebuild and trying to by some time.

BuckeyeDemon

assuming it's not just the gauge playing games with you, could it be a galley plug starting to come loose/open up?

guitarman376

Its possible that somethings loose. I have had no time lately to dig into it yet, some friends and I are competing in the 24hrs of lemons and that has been taking all my time.

1970

im thinking cam bearings wernt replaced and he recomended that oil to hide the fact

Jaildoe1

Does anyone see pressure numbers or a yr of motor? My 351w 1969 runs 58 cold and 12 at hot idle. normal when driving. id like to see numbers.

Derf00

I think you already have your answer from this thread and the one I posted in.

Try thinner oil. 20w-50 is too thick for a freshly rebuilt engine and any modern engine.

https://mustangforums.com/forum/oil-...ml#post8718174