Posts by 6T09KGT

Kevin,

Some additional food for thought:

1. Mobil 1 15W-50 is formulated for flat tappet engines. This is all I’ve used for the past 35 years and has and both phosphorus and zinc levels can be found here https://www.mobil.com/lubricants/-/m…C94A7396657AC09

2. If you need to bore the block, depending on the severity of damage you can go to .040 instead of .060.

3. I’m sure you’ll discover the root cause when you do a tear down but with metal debris on only the drivers head and extra loose valves, did you also check for bent push rods?

Valves definitely sound loose, start there. Where does the oil pressure needle sit at idle? Although not the most accurate, anything below midpoint would could concern. You can add a mechanical gauge by putting a T fitting on where the stock pressure gauge is.

It could be a rod bearing but that knock usually becomes more pronounced during engine deceleration. Have you tried to rev the engine and does the noise change when the revs come down?

As a precaution, you may want to drain the oil to see if there is any sign of metal in it.