Here’s my situation. I just had my 340 completely rebuilt. When I took it to the Dyno we notice the frost plugs where missing. No big deal we didn’t start the water yet. Installed frost plugs. We started the 15 minute break in. The Dyno guy noticed the oil filter temperature was only at about 80 degrees and not following the engine temp up. After the break in time was up we determined the plug under the 90 degree filter housing was never installed. So during the break in time the filter wasn’t doing much of anything. The oil was bypassing the filter. After we put the plug in the block, the oil filter temp followed the engine temp up.

My concern is the damage that might have been done to the bearings etc. Should I have a third party take a look at the oil filter (for debris), bearings and pan? The engine builder hasn’t gotten back to me yet, not sure if he will.