Stock 2.8 cam specs?

[Justin]

Anyone know the full cam specs for a 1989 2.8? I have the lift specs, intake .2626, exhaust .2732, but how about duration? I'm thinking about getting the HiPo GM cam off of ebay, and it has more lift, but I was wondering if there was a big duration difference as well.

[Brian P]

I believe the cam for the High output 2.8 used in cars like the citation X11 is the same one GM used on FWD 2.8's also. Could probably look it up on gmpartsdirect.com

[Justin]

stock 2.8 cam: Lift intake .262, Lift Exhaust .273

HiPo 2.8 cam: Lift intake .394, Lift Exhaust .410

Crane compucam: Lift intake .401, Lift exhaust .423

 

Duration HiPo: intake 276, Exhaust 293

Duration Crane: intake 258, exhaust 264

 

Crane #s are from the smaller 2020 cam.

 

You might be right, I was researching and found this site, it has the specs for every 2.8/3.1 cam imaginable. http://www.engine-parts.com/GMV6/28camspecs.html

I think the lift specs in my service manual may be skewed some, not advertised lift like the other 2.

[gpse3200]

Take the .262 and the .273 times it by 1.5(rocker ratio) and you got the lift. The "Hi Po 2.8"cam and the Crane Cam have already done that. you'll know the real lift by divding. So the Stock 2.8 cam is your HiPo cam. Go for either thge 2030, 262, or the highest lift From Compcams(not sure about the modle). Don't worry about your springs, they will definatly hold and provide enough pressure providing you don't have 300,000 miles on the engine. GM also seemd to use forgiving springs.

[gpse3200]

What youl need to do is get the rocker studs and nuts from a GEN1 engine, becasue the lifter preload may not be correct and for th emost power, you'll have to adjust them. Once adjusted they don't come loose and they run forever.