Author Topic: Vacuum Reading - 302 Engine  (Read 1858 times)

rockphil

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Vacuum Reading - 302 Engine
« on: June 19, 2009, 10:08:47 PM »
I have a 69 Z28 with the original 302 engine. The vacuum reading is 12 to 13". I am unsure if it has the original cam.

A couple of questions for anyone who may have the answers:

(1) What should the vacuum reading be for a factory stock 302 engine with no additional options other than the factory installed items (front disc brakes, no A/C)?

(2) How (if at all) does the vacuum affect the funtioning of the cowl induction system (mine does not appear to be working)?

Rocky

1968RSZ28

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Re: Vacuum Reading - 302 Engine
« Reply #1 on: June 19, 2009, 10:33:03 PM »
I have a 69 Z28 with the original 302 engine. The vacuum reading is 12 to 13". I am unsure if it has the original cam.

(1) What should the vacuum reading be for a factory stock 302 engine with no additional options other than the factory installed items (front disc brakes, no A/C)?

http://www.camaros.net/forums/showthread.php?t=62634

Paul

JohnZ

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Re: Vacuum Reading - 302 Engine
« Reply #2 on: June 20, 2009, 03:08:09 PM »
Most Z/28's (and '64-'65 L76 and L84 Corvettes) I've worked on, with their original "30-30" cam, showed 9"-11" of vacuum at a 900 rpm idle.

Manifold vacuum has nothing to do with the operation of the ZL2 hood - it's operated electrically by a solenoid, from a plunger switch on the accelerator lever and a relay on the firewall.
'69 Z/28
Fathom Green
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rockphil

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Re: Vacuum Reading - 302 Engine
« Reply #3 on: June 20, 2009, 03:27:06 PM »
Thanks Paul and John,

Great answers..

Rocky

smith69z

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Re: Vacuum Reading - 302 Engine
« Reply #4 on: June 20, 2009, 03:28:24 PM »
Mine is 10 at 900 just as John stated. Just enough to feed the power brakes.