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Almost an old guy...
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180 Posts
Discussion Starter #1
The story,
SBC 350 .030 over, cam specs: @.050 Intake duration 204, lift .420, exhaust duration 214 lift .443 , 1.5 rockers

Vac at idle (800 rpm) is around 12 inches, I was expecting more, idle is choppy, I was expecting smooth.... did I buy one thing and get another???? anyway to check without tearing into the engine?

I've checked for vac leaks around carb and intake none found, I won't get the exhaust on till tomorrow so I can't take it for a drive to see how it really runs until tomorrow.

Any ideas or am I just barking up an empty tree????
 

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Race it, Don't rice it!
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7,810 Posts
You didn't post the overlap figures or the LSA but just a good guess it should pull round 17 or maybe better at 700rpm. You got a pretty conservative cam for a .030 over flat top motor. Sounds like you need to investigate the timing and carb idle tune. Both of those wIll have the biggest impact on vacuum at idle.
 

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Time is short, are you ready?
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655 Posts
How Soon We Forget

Johnsongrass1,
I'm surprised you didn't ask him if he verified the accuracy of his gauge. You brought this question to my attention a while back and guess what, you were right! :thumbup:
http://hotrodders.com/showthread.php?s=&threadid=43549

Lance,
If you don't have another gauge to check your engine with, attach you current gauge to a new engine with good vacuum. I checked mine against a brand new Tundra and only got 14" at idle in park. I figured the gauge was reading at least 5" low.

Good luck, Ed www.edgesz28.com

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Who is Jesus?.:)
 
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