140 cam.........................how much vacuum ?

[Dr L-88]

I'm sure some of you have run the 302 Z/28 140 cam in your small blocks at one time or another. I am curious as to how much vacuum this cam will generate.

Here are the cam specs:

First Design Off-Road cam, P/N 3927140
Casting #3927141
Intake 257 duration @ .050" (333 advertised)
Exh. 269 duration @ .050" (346 advertised)
Lift: .493" intake, .512" exhaust
Intake Max lift @ 108 deg. ATDC
Exhaust Max lift @ 116 deg. BTDC

As always, thanks in advance for your input. 
Rex

[69z28302]

Rex you didn't buy a Camaro did you?
Mike

[Dr L-88]

No.........................still stuck with this old Corvette 

[Jon Mello]

Rex, I ran the 140 cam in my old '69 Z for three years and never had a gauge on it to measure the actual vacuum, but there was never an issue with the operation of the power disc brakes, if that is the area of your concern.

[BillOhio]

My car still has one. Never noticed anything funny on my brakes. If you want to hear one, there's some videos on you tube.

[Oaklyss]

6-7"hg. Use an adjustable vacuum advance unit. Change power valve(s) to 3.5 and add power valve blow-out protection as engine will pop sometiimes when cold. And nothing sounds like these cams!

[JohnZ]

The stock Z/28 cam (-346) will pull about 9"-10" Hg. at 900-1000 rpm; I'd expect the "140" off-road second design cam to pull about 2" less.