Author Topic: 140 cam.........................how much vacuum ?  (Read 4446 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

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

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

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.
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.
1969 Z28, Burgandy, numbers matching, 12,900 miles
1968 RS 327 4 speed
1967 Plymouth GTX Hemi, 4 speed, dana
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!
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.
'69 Z/28
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