Just like the title says.....

How much vacuum should you have with a CC503 and 1.6 pro mags at idle?

 

I would like to know this as well. What problems are you having?

 

My old gm846 cam which is very similar got right at 15.5" in park at 925rpm and it got 13.5" in gear at 800rpm.

 

I'm not sure if I have any problems yet.

I just completed putting the engine back in the car and took it for a little test drive. I didn't have a full exhaust on it....had just cat y-pipe on it....and I never went above 3500rpms for break in purposes....

But man it felt weak on the low end(PCM is tuned)......

It idles fine, the pro mags sound great, oil pressure is 60psi(white spring).....it just feels weak. Now, I'm hoping all my power is on the top end...but I was wondering what the vacuum was on other CC503 installs because that is a indicator of engine health, rocker settings etc.

I'm pulling 16 psi of vacuum with this cam now.

I've read that the hotcam does around 15 so....if that is the case then I think I'm in good shape with vacuum leaks etc....

However, I'd find it very helpful if someone with stock heads,1.6 rockers, and a CC503 would take a quick vacuum reading.

Also for reference, my idle setting is 850.

 

Sorry I don't have a vacuum reading for ya (I don't have a gauge), but I'm running a CC503 with aftermarket heads, COMP ProMags and LT's. My idle is set around 850rpm also. Maybe I can help with a couple of things. The CC503 will really wake up over 3500rpm, so forget the advertised 1800-5800rpm range. It's more like 3500-6500rpm. The other is if you're running stock gears.....it ain't helping any.

Jon G - Electrical Engineer - VT
Red 96Z, OBDI conversion, A4, Yank 3200 stall + other goodies.

 

That's good to hear. I'm going to put my muffler on it tonight(tired of it sounding like a logging truck). When the rain breaks here....I plan to drive it varying the RPM's then get into it some...to see what it can do.