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I'm Your Pusher
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Discussion Starter · #1 ·
After seeing the success with the large bore gains, one of our 9 second Vs decided to pull the trigger on the medium bore heads and see what kind of magic will be worked. Stay tuned!
 

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I'm Your Pusher
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Discussion Starter · #3 ·
Says the guy who's sky lifted Dyno queen has never seen a track. Try getting a slip of your own... take that skirt off, you might like it lol
 

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Says the guy who's sky lifted Dyno queen has never seen a track. Try getting a slip of your own... take that skirt off, you might like it lol
Wow - that's some first rate trash talk right there man!

Ben - help out a novice here. Why go medium bore instead of large bore?
 

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I'm Your Pusher
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Discussion Starter · #5 ·
You always want to do large bore but you need a 4.125 bore min. The large bore allows larger valves. Med bore will shine shortly though too. :)
 

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Says the guy who's sky lifted Dyno queen has never seen a track. Try getting a slip of your own... take that skirt off, you might like it lol
Lmao!!

Sent from my SCH-I605 using Tapatalk 2
 

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Not to mention that the large bore lets the valve breathe better on the cylinder wall side of the combustion chamber but if the edge of the bore is in the way it creates a step that has a negative effect on airflow into the cylinder... To have larger valve in most heads means the valve guide centerline must be spread apart to have enough room for the larger valves.............
 

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Dick Pickles
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Very interested in the info on these.
 

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I'm Your Pusher
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Discussion Starter · #10 ·
Not to mention that the large bore lets the valve breathe better on the cylinder wall side of the combustion chamber but if the edge of the bore is in the way it creates a step that has a negative effect on airflow into the cylinder... To have larger valve in most heads means the valve guide centerline must be spread apart to have enough room for the larger valves.............
Correct, these are a 4.125 bore min but we're doing a set of medium bores now too... you guys wouldn't have believed what these flowed in the midwest out of the box. I was holding off till the Med bore are done but whatever.

Down in TX, these are advertised to flow 387 at .700 lift
Here they flowed 353cfm intake and 223 exhaust

Result:
We worked them out to 393.7 intake and 264.3 exhaust! That's an intake net gain of 38CFM or 10%! Gains started early too... .400 lift they were only 266cfm and after 308.2cfm.

I can't wait to get the Mast LS3 Medium bores done! I'll give you a hint, out of the box here, they flowed only 3cfm more than my weaponX LSA ported heads!
 

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8s are the new 9s
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Correct, these are a 4.125 bore min but we're doing a set of medium bores now too... you guys wouldn't have believed what these flowed in the midwest out of the box. I was holding off till the Med bore are done but whatever.

Down in TX, these are advertised to flow 387 at .700 lift
Here they flowed 353cfm intake and 223 exhaust

Result:
We worked them out to 393.7 intake and 264.3 exhaust! That's an intake net gain of 38CFM or 10%! Gains started early too... .400 lift they were only 266cfm and after 308.2cfm.

I can't wait to get the Mast LS3 Medium bores done! I'll give you a hint, out of the box here, they flowed only 3cfm more than my weaponX LSA ported heads!
That sux
 

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I think I mentioned previously that for some reason the Mast heads don't flow the numbers out of the box, but they can flow very well with some touching up.
 
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