un-used pully attached to cam

[68'911]

Alright we were thinking of doing the carrera tensioner upgrade but don't know how they would fit considering this (pully thing?), to be quite honest i don't know what it is or what it is for, cause we can't see that it has ever attached to anything. (we were thinking mabey smog pump at on time?) So i guess first of all: what is this seemingly worthless thing and second is can i remove it in favor of some diff chain housings and what-not? Third i suppose is to be asked only if the second was answerd yes; how is it done?

any help will be greatly appreciated.

-68'911

[68'911]

no one knows?

[jgparker]

The pully is for an air pump for the 1968 only emissions controls. On my 68, I cut the pully drive off the cam, and replaced the covers with the new ones, wich allowed for the carrera oil fed chain tensionsers. I know of several other people who had the stock 68 cover machined to accept the oil fed tensionser. It really depends on what you goal is with the car, and the amount of work you want to put in. If you want to win pebble beach, you need to keep the pully and add the pump back in. If you want it to look clean, ditch the pully. The pump never did anything for performance, and it is not likley to help much with smog test.

good luck,

JP

[Wayne 962]

Yes, smog pump. You can modify your chain tensioner covers to fit the new tensioners by drilling out a precision hole for the inlet to the tensioner...

-Wayne

[jgparker]

The nice thing about those '68 911L cams is they are actually E-cams, except that the left one has the air-pump take-off. The right one is even the same part number as the E- cam.

[68'911]

Thanks for the info guys, I guess what I do will depend on the money i have lefrt nearing the end of my rebuild. Most likely will ditch the pully.

If the smog pump doesn't cut emissions then why would porsche put it on the engine?, it's not cause it looks good

[jgparker]

The air pump adds extra oxygen to the exhaust to help burn off excess hydrocarbons, but without a catalytic converter, it does not work very well. It did help a little, but it was ugly.

[ChrisBennet]

Wow. I thought '75 was the first year of emmisions controls. I guess you learn sumptin' new every day.
-Chris

[ValveFloat]

This may sound a little ghetto, but I cut the extra length of the cam for the pulley off with a hack saw. Turned out just fine.