Oil Pressure Relief and Safety Valves

[DavidSwedem]

I am rebuilding a 1971 911T 2.2
The engine does not have the oil bypass modification and I am using the original 3 rib pump.

I am confused regarding what springs and pistions to use in the oil relief and safety valves.

Do I use the original type or change to year 78 type?

[stownsen914]

If you don't have the oil bypass mod done, you need to stick with the earlier style relief valve piston and spring as they are not interchangeable with the later ones. Safety valve piston and spring are not updated on the later cars so you can stick with what you have.

Inspect the bores and pistons for wear or scoring. Also check the springs for relaxed length. It should be 70 mm for both of yours. They can wear out, I pulled a safety valve spring for my rebuild that is only 61 mm. Some replace the springs just because.