318 crusader oil pressure

[jth21usa]

On my starboard engine, which has never been rebuild after 41 years, when I run for 4-5 hours my oil pressure will very gradually drop from 45 to 30. I go into the engine and add a half a cup of oil and i am all set for another 2 days. Is this something that is fixable or on 40 year old engines is this a quirky thing that I deal with.

 

things I’ve already fixed:

 

1. Small oil leak in two different spots 

2. Valve cover caps replaced 

 

could it it just be a worn out oil pump? Or should I be using 10w-30 oil instead of 10w-40?

[Xxx]

If you only lose 15lbs of oil pressure that's) well into the OK zone!!. If its not smoking blue out the exhaust and only a 1/2 cup of oil is being used thats fine, in my book thats not ready to be pulled yet. Especially on a Chrysler product the old 318's were great engines and other then their power house motors the 318 was there mainstay motor!!!

[L&M]

On 5/26/2019 at 12:07 AM, jth21usa said:

Or should I be using 10w-30 oil instead of 10w-40?

 

Stay away from the multi viscosity oils and use the recommended straight weight oil it was intended to use when it was built & you should see a considerable difference in both consumption & pressure. 

Factory recommendations for that era 318/360 is straight 30w in temps above +30* fahrenheit 

Shell Rotella would be my first choice