Good mornin' folks! New memeber here. Heard some disparaging info. about many oil mfgrs. are deleting or reducing the amt. of Zinc & Phosphorus in their oils, which supposedly helps in protecting flat tappet cam applications (good old pushrod solid lifter stuff like my favorite 289 HiPos.) What's the story here and is it true? What oil/s are best for these types of engines? Is there a list of oils that would show the % content of their Zinc & Phosphorus? Any help would be very much appreciated.
Oil protection for flat tappet cam engines
- Thread starter 289HIPO
- Start date
- Status
Lots on this subject if you do a search...and
Welcome aboard!
I would very much recommend doing a search for "flat Tappet" as this topic has been
recently.
Essentially, with a stock DOHC modern solid flat tappet lifter type valvetrain, modern passenger car oils are fine, well, better than previous API spec oils. Zinc has not been eliminated; phosphorous (part of the zinc compound used) has been reduced to 800 ppm max with SM/GF-4.
If you have an older V-8 OHV engine or a high performance flat tappet valvetrain with insane valve springs, then it seems these are the engines experiencing issues with SM/GF-4 and even SL/GF-3 oils. For those types of engines, something like a heavy duty engine oil like Shell Rotella or Chevron Delo would work better, or Valvoline VR-1.
It's been noted here that the amount of zinc is not the problem in and of itself. Zinc gets depleted or used up so to speak, and the reduction essentially shortens the useful lifespan of the zinc in the oil (not an issue though with modern engines, especially roller valvetrain stock engines). Perhaps the zinc in a modern passenger car oil just gets eaten up very quickly in a high performance solid lifter engine.
I would very much recommend doing a search for "flat Tappet" as this topic has been
Essentially, with a stock DOHC modern solid flat tappet lifter type valvetrain, modern passenger car oils are fine, well, better than previous API spec oils. Zinc has not been eliminated; phosphorous (part of the zinc compound used) has been reduced to 800 ppm max with SM/GF-4.
If you have an older V-8 OHV engine or a high performance flat tappet valvetrain with insane valve springs, then it seems these are the engines experiencing issues with SM/GF-4 and even SL/GF-3 oils. For those types of engines, something like a heavy duty engine oil like Shell Rotella or Chevron Delo would work better, or Valvoline VR-1.
It's been noted here that the amount of zinc is not the problem in and of itself. Zinc gets depleted or used up so to speak, and the reduction essentially shortens the useful lifespan of the zinc in the oil (not an issue though with modern engines, especially roller valvetrain stock engines). Perhaps the zinc in a modern passenger car oil just gets eaten up very quickly in a high performance solid lifter engine.
- Status
Similar threads
- Locked
- Locked