View Full Version : Engine Vacuum


kencar69
Dec 16th, 08, 07:56 AM
Assuming I do not have a vacuum leak, which I'm sure I do not, Is there a way to increase engine vacuum? I thought I read something one time on how to add vacuum by adding a stand alone source.

Its been a while since I checked, but when using a vacuum gage, my motor was not in the normal range. I do have to much cam, in addition to still running the original exhaust manifolds and not headers. I just like the lumpy idle I get.

67CamaroRS/SS
Dec 16th, 08, 08:32 AM
I run Rhoads variable duration lifters and IMO, they are the best way to increase vacuum, but they are for hydraulic cams. They will work on solid cams, according to Rhoads, but some say they defeat the purpose of a solid cam. The vaccum tanks are ok, but they can still run down. What exactly are you trying to get more vacuum for? Brakes? If brakes, then make the switch to hydroboost. Best thing you will ever do.

Everett#2390
Dec 16th, 08, 10:01 AM
Increase initial timing and curb idle.

kencar69
Dec 17th, 08, 04:29 AM
Most part everything is OK, brakes are a little soft at first but are good. Was thinking low vac could be the reason my RS lights dont function to well.

Everett#2390
Dec 17th, 08, 04:36 AM
A vacuum gauge hooked to intake manifold (full time) indicates _______in. of vacuum.

An OE Z/28 comes standard with a brake booster and with the RS option, the engine creates 9 in of vacuum. I think there is a reservior with a check valve inside the drvr fender by the firewall to assist the headlamp doors.

67CamaroRS/SS
Dec 17th, 08, 07:40 AM
For that you need to make sure all the hoses are in good shape. That is the reason A LOT of 68/9 RS owners are converting theirs to electric doors. The time consumed maintaining the vacuum hoses is a PITA. That is 1 of the good things about a 67 RS. Provided you have a hydraulic cam, the Rhoads variable duration lifters will increase your vauum up to 5".

rszmjt
Dec 17th, 08, 09:08 AM
Another common problem is that the RS headlight hinge and door bushings are worn out and binding, a little lube also helps as they tend to get sticky as well with road dirt and dust.
I just fixed 1 the other day and it had spit hoses at the lower actuators.

kencar69
Dec 18th, 08, 05:26 AM
Yeah, I already picked up a bushing kit for the doors, just havn't replaced them yet. At present my doors will open, but without assistance they won't close.