Vacuum leak add power

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RCJ
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Vacuum leak add power

Post by RCJ »

If you have a restricted carb because of rules can you use a vacuum leak to add some power?
Brian P
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Re: Vacuum leak add power

Post by Brian P »

I know it's been done ...

It depends whether the organizers wise up to it and write the rule in a way that prohibits it and which they can enforce.
DrillDawg
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Re: Vacuum leak add power

Post by DrillDawg »

What is the restriction, carb size or plate.
BORN RIGHT THE FIRST TIME
wwmtlineman
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Re: Vacuum leak add power

Post by wwmtlineman »

Worked back in the late 60s for NHRA stockers until they caught on and used a sniffer to check them. A lot of 2 barrel cars slowed down after that. They would idle around in a black cloud of rich mixtures
RCJ
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Re: Vacuum leak add power

Post by RCJ »

Carb , but how would a plate be different?
Fireonthemountain
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Re: Vacuum leak add power

Post by Fireonthemountain »

wwmtlineman wrote: Fri Jun 15, 2018 11:51 am Worked back in the late 60s for NHRA stockers until they caught on and used a sniffer to check them. A lot of 2 barrel cars slowed down after that. They would idle around in a black cloud of rich mixtures
3 deuces cars used it as well then. I have thought of other leaks that might be beneficial in a similar way without changing or raising idle mixtures. My head is still stuck back then in many ways, in my thinking.
pamotorman
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Re: Vacuum leak add power

Post by pamotorman »

put on a fake vented inside the car power brake reservoir with a vacuum line to back of the carb base. you can close the leak inside the car for tech inspection.
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Re: Vacuum leak add power

Post by pamotorman »

Fireonthemountain wrote: Sun Jun 17, 2018 12:46 pm
wwmtlineman wrote: Fri Jun 15, 2018 11:51 am Worked back in the late 60s for NHRA stockers until they caught on and used a sniffer to check them. A lot of 2 barrel cars slowed down after that. They would idle around in a black cloud of rich mixtures
3 deuces cars used it as well then. I have thought of other leaks that might be beneficial in a similar way without changing or raising idle mixtures. My head is still stuck back then in many ways, in my thinking.
just enlarge the power valve fuel feed drilling and it will not affect the idle richness as you are only looking to richen up wide open throttle.
Fireonthemountain
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Re: Vacuum leak add power

Post by Fireonthemountain »

pamotorman wrote: Sun Jun 17, 2018 6:09 pm
Fireonthemountain wrote: Sun Jun 17, 2018 12:46 pm
wwmtlineman wrote: Fri Jun 15, 2018 11:51 am Worked back in the late 60s for NHRA stockers until they caught on and used a sniffer to check them. A lot of 2 barrel cars slowed down after that. They would idle around in a black cloud of rich mixtures
3 deuces cars used it as well then. I have thought of other leaks that might be beneficial in a similar way without changing or raising idle mixtures. My head is still stuck back then in many ways, in my thinking.
just enlarge the power valve fuel feed drilling and it will not affect the idle richness as you are only looking to richen up wide open throttle.
Or have the leak above the blades.......
shiftbyear
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Re: Vacuum leak add power

Post by shiftbyear »

I read an article some years back of a nascar team that got penalized for running hollow intake manifold bolts, the bolts were also drilled just under the head to provide an airpath. Desperate times....
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