Manifold Vacuum Reading?

[msemtr]

Hi,

Been trying to get my hotcam to run well and am having issues with surging while cruzing with very little to no throttle. Idle is steady at 825 RPM with AC on but I feel could be smoother. Been playing around with timing and the VE table for awhile but can't seem to get rid of the surging.

While going over my logs, I noticed that my manifold vacuum is only at about 7 PSI at idle and will hit 10 PSI at the highest when cruising in no load/high vacuum situations. This points to a vacuum leak which also may be contributing to a rougher idle and surging while driving. Funny thing is that my LTRIMS were not way positive and are actually pretty good after a little VE table work. Power brakes work fine and I could not find any leaks in the obvious places.

My old 355 chevy with a decent cam would pull about 12-15 PSI at idle. What vacuum reading should I expect with a hotcam?

Thanks guys!

[killer01ws6]

I am not sure what normal is....
but on my H/C car with the tune still in need...lol

I am running 5.xx to 16.xx psi.

[TT_Vert]

my stock car sees 10 psi and 19.x hg/in.

Dave

[luv2spd]

I think I pull about 6.2 psi of vaccuum with my cam at an idle of 875.