Switching to synthetic
Pro
Joined: Feb 2017
Posts: 518
Likes: 365
From: San Diego
2023 C3 of the Year Finalist - Modified
Constant high temps and scraping of the rings on the cylinder walls would not allow it to build up to such a degree as to create a lack of sealing during break in. Part of breaking in the rings is to accelerate and decelerate aggressively to force the rings into the cylinder walls, forcing metal to metal contact. The zinc likely does in fact get into the metal of cylinder, the low points. The rings still ride on the high points, or what are left of them at least, constantly scraping the cylinder walls.
Thread Starter
Heel & Toe
Joined: Oct 2021
Posts: 22
Likes: 10
Yeah thanks. I didn’t grow up with these old cars so I’m trying to learn as much as I can to keep it going. So much info on this website it helps me all the time. Still going to add the zinc after making the switch
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
The higher zinc quantity was specifically for the flat tappet cams. If you don't have flat tappets then it can be reduced. Modern every day oils contain sufficient zinc for roller cams.
