'65 Mustang coupe with mild cammed 302 engine- Use to run yellow death (Pennzoil) but after losing a cam, I have switched over to 15w40 Royal Purple. Engine is much quieter so I guess I should be happy with it?
'67 GTO HO 400-Passed on from my late brother last year. The last oil introduced into the engine before I picked up the car was/is Castrol Syntec 10w40.
Both cars have flat tappet cams.
Now recently I sent a sample of unused oil from each of the above oils to a test lab and got the following Zinc and Phosphorus levels.
Royal Purple
Zinc: 989
Phos: 891
Castrol Syntec
Zinc: 648
Phos: 545
For a flat tappet cam, I am surprised that I find such low levels of Z & P in the Castrol oil and am a little disappointed that the Royal Purple wasn't closer to 1200+
Both cars are occasional drivers putting maybe 2k-3k miles on annually. Don't I want a zinc level closer to 1500ppm? Thinking Brad Penn which I can get locally for less than $5/qt, or Valvoline VR1 or what?
I'm currently restoring another vintage Mustang which will have a stroked 331 so I'll be needed to address this issue again.
My Chevy truck is still running 30w non-detergent oil and won't let me change it. Way too happy hauling Mustang parts around.
'67 GTO HO 400-Passed on from my late brother last year. The last oil introduced into the engine before I picked up the car was/is Castrol Syntec 10w40.
Both cars have flat tappet cams.
Now recently I sent a sample of unused oil from each of the above oils to a test lab and got the following Zinc and Phosphorus levels.
Royal Purple
Zinc: 989
Phos: 891
Castrol Syntec
Zinc: 648
Phos: 545
For a flat tappet cam, I am surprised that I find such low levels of Z & P in the Castrol oil and am a little disappointed that the Royal Purple wasn't closer to 1200+
Both cars are occasional drivers putting maybe 2k-3k miles on annually. Don't I want a zinc level closer to 1500ppm? Thinking Brad Penn which I can get locally for less than $5/qt, or Valvoline VR1 or what?
I'm currently restoring another vintage Mustang which will have a stroked 331 so I'll be needed to address this issue again.
My Chevy truck is still running 30w non-detergent oil and won't let me change it. Way too happy hauling Mustang parts around.