View Single Post
ChrisBennet ChrisBennet is offline
Registered User
ChrisBennet's Avatar
Join Date: Aug 2001
Location: Nashua, NH USA
Posts: 8,089
Adventures in cam measurement

Hi guys,
A friend and I are trying to figure out what sort of cam he has in his 2.8L (?) motor that used to have carbs. It was originally a 1972 911E motor. We put a dial indicator on the valves for #1 so we could see what the were doing and this is what we got:

(Rough approximate, degrees of crank rotation)
0 deg Both valves closed, crank at TDC
123 deg Exhaust Opens
322 deg Intake Opens
386 deg Exhaust Closes
604 deg Intake Closes

Based on those figures I get an intake duration of 282 degrees and an exhaust duration of 263 degrees.

I'm embarassed to say why I didn't measure the lift.

We looked in Waynes book but either it's not listed in there or (more likely) we're eligible for a "deminished capacity" defense.

Help us out?
'80 911 Nogaro blue Phoenix!
'07 BMW 328i Coupe
Old 03-31-2005, 06:36 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)