Thoughts on 'cam-shield' zinc additive
03-24-2019, 10:12 PM
#21
Le Mans Master
Its not just high valve-spring pressure that has wiped cam lobes. I have seen stock L48 low pressure springs wipe a cam too. A 35 yr old set of springs.
Its not just the pressure on the lifters & cam. Its the constant friction without any zinc that destroys the metals. Zinc is a coating designed for metal to metal contact
Remember, Zinc was introduced to automotive oils several decades ago and has been removed from oils less than a decade ago. That's why we are still seeing wiped cams showing up on forums.
Nine years ago I knew nothing about zinc. Never heard of it. I used average brand, off-the-shelf oil that was on sale. Made it three years, then the unmistakable sound
showed up.
To think and to say that zinc is not needed in Flat Tappet engines is a Ostridge head in the sand approach to being mechanically minded.
Its not just the pressure on the lifters & cam. Its the constant friction without any zinc that destroys the metals. Zinc is a coating designed for metal to metal contact
Remember, Zinc was introduced to automotive oils several decades ago and has been removed from oils less than a decade ago. That's why we are still seeing wiped cams showing up on forums.
Nine years ago I knew nothing about zinc. Never heard of it. I used average brand, off-the-shelf oil that was on sale. Made it three years, then the unmistakable sound
showed up.
To think and to say that zinc is not needed in Flat Tappet engines is a Ostridge head in the sand approach to being mechanically minded.
03-24-2019, 10:48 PM
#22
Le Mans Master
https://www.onallcylinders.com/2018/...to-save-money/
Worth the read.
Now I'm curious. I may be wrong but I believe 1200 is the correct amount of zinc for high lift flat tappet cam. How does more than this cause problems. Just wondering?
Worth the read.
Now I'm curious. I may be wrong but I believe 1200 is the correct amount of zinc for high lift flat tappet cam. How does more than this cause problems. Just wondering?
Last edited by Vette5311; 03-26-2019 at 12:14 AM. Reason: more information
04-02-2019, 08:57 AM
#23
It doesn't untill you reach absurdly high levels afaik.
The racing oil I used for classic mini's had 1600 ppm.
The racing oil I used for classic mini's had 1600 ppm.