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Discussion Starter · #1 ·
Just got the motor running and installed a vacuum gage. It has 5" at 1100rpm's (idle), 10" at 3000rpm and 15" at 4500rpm. I didn't take it any higher because I heard that the vacuum should never be over 10". If I have 15" at 4500rpm's, it's gonna be way over 10" at 7500!! I have a bleeder in the valve cover that uses carb jets regulate the vacuum.? How many inches of vacuum should I be looking for?
 

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out of work hair dresser
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Just got the motor running and installed a vacuum gage. It has 5" at 1100rpm's (idle), 10" at 3000rpm and 15" at 4500rpm. I didn't take it any higher because I heard that the vacuum should never be over 10". If I have 15" at 4500rpm's, it's gonna be way over 10" at 7500!!
Way over 10" at 7500 = not necessarily. The harder the engine turns, the more crankcase pressure is built......in normal cases (not all). Your vacuum pump can only pull but so much vacuum regardless of RPM (it has it's peak volume). You need to run it as it is under load and monitor the vacuum during. An average of 12" and no higher than 15" should render you no problems.
 

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T/S 368E
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I also shoot for 15, never higher. 12-15 is safe & effective for what we are trying to do.

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I also shoot for 15, never higher. 12-15 is safe & effective for what we are trying to do.

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X2

Anything over 15-16 inches, coated wrist pins are highly recommended.

My set-up pulls 12-14.
 

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Discussion Starter · #5 ·
Don't know if it makes a difference or not, but it's a wet sump system with a street style Moroso Stroker pan with baffles and a Moroso oil pump. 8 quarts of oil in the motor.
 

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T/S 368E
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I just got a new Weaver 5 stage. Tech reminded me, do NOT go over 15.
They said pump will pull more, but don't use it without some kind of relief deal.

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When the chrome comes off the trailer hitch.

Oh wait, wrong thread.
 
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