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Author Topic: 140 cam.........................how much vacuum ?  (Read 6737 times)

Dr L-88

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140 cam.........................how much vacuum ?
« on: January 21, 2015, 03:04:28 PM »
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
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69z28302

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Re: 140 cam.........................how much vacuum ?
« Reply #1 on: January 22, 2015, 03:00:00 AM »
Rex you didn't buy a Camaro did you?
Mike
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Dr L-88

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Re: 140 cam.........................how much vacuum ?
« Reply #2 on: January 22, 2015, 03:24:31 AM »
No.........................still stuck with this old Corvette  ;D
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Jon Mello

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Re: 140 cam.........................how much vacuum ?
« Reply #3 on: January 22, 2015, 05:04:51 AM »
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.
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Jon Mello
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BillOhio

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Re: 140 cam.........................how much vacuum ?
« Reply #4 on: January 23, 2015, 01:25:51 AM »
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.
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1969 Z28, Burgandy, numbers matching, 12,900 miles
1968 RS 327 4 speed
1970 Z28 M22 4:10 bought from original owner
1961 Chrysler 300G convertible

Oaklyss

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Re: 140 cam.........................how much vacuum ?
« Reply #5 on: January 23, 2015, 02:46:45 PM »
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!
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69 RSSS ZL-2 4 speed, mint unrestored 04A LA built-SOLD
1968 GTCS mint unrestored original paint
1972 AMX 401 4 speed, cowl induction, twin-grip, A/C, unrestored, original paint
1963 Oldsmobile Jetfire factory Turbo and Methanol injection, 4 speed, posi, 1 of 4 known to exist

JohnZ

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Re: 140 cam.........................how much vacuum ?
« Reply #6 on: January 23, 2015, 05:31:13 PM »
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.
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'69 Z/28
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