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  #1  
Old 2 Weeks Ago
syclonedave syclonedave is offline
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Default No Hemis in PS

So, if a hemi style head is "the best" for flow, why is it being beat by POLYs...Rat motors ? I guess I'm missing something.
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  #2  
Old 2 Weeks Ago
HEMI_guy HEMI_guy is offline
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With another 500 rpms it could be as competitive as the rest.

BTW... keep an eye on the Geoff Turk Challenger in the Factory Stock Shoot-out. I had a very intersting talk with him on Sunday. He explained why others have failed at being competitive with Dodges in the class and his theory on why we're not seeing Cobra Jets running in the 7's in legal trim anymore.
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Old 2 Weeks Ago
A Poole A Poole is offline
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Originally Posted by syclonedave View Post
So, if a hemi style head is "the best" for flow, why is it being beat by POLYs...Rat motors ? I guess I'm missing something.
The current hemi's are not true hemi's even tho they want you to believe they really are.
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  #4  
Old 2 Weeks Ago
syclonedave syclonedave is offline
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Originally Posted by A Poole View Post
The current hemi's are not true hemi's even tho they want you to believe they really are.
How are they different ?
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  #5  
Old 2 Weeks Ago
syclonedave syclonedave is offline
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Quote:
Originally Posted by HEMI_guy View Post
With another 500 rpms it could be as competitive as the rest.

BTW... keep an eye on the Geoff Turk Challenger in the Factory Stock Shoot-out. I had a very intersting talk with him on Sunday. He explained why others have failed at being competitive with Dodges in the class and his theory on why we're not seeing Cobra Jets running in the 7's in legal trim anymore.
It this since the limit was lowered ? Isn't it 10.5 now ?
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  #6  
Old 2 Weeks Ago
Roger Gates Roger Gates is offline
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Originally Posted by syclonedave View Post
How are they different ?
The "Hemi" is a copywrite name that Chrysler got when they had a cylinder head that had a hemispherical combustion chamber. It is not a "real term" just like "tranny " or "pumpkin" are slang. They chose to use the name on the newer head that is basically a "twisted wedge" design. In actuality they can call anything a "Hemi" because they have rights to the name. The Nitro cars do use an almost true hemispherical design, but a simplified explanation is the unblown gas engine likes some "pinch", (closing up the chamber) because to get the compression where it needs to be there will be a cool area around the perimeter because the piston dome is too large with the hemispherical chamber and it blocks the flame travel. Reality is the valves are just vertical instead of horizontal on the "Hemi" but that makes a difference on the Pro Stock engine with the rules package that NHRA has.
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  #7  
Old 2 Weeks Ago
HEMI_guy HEMI_guy is offline
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Originally Posted by syclonedave View Post
It this since the limit was lowered ? Isn't it 10.5 now ?
I'm just going on what a number of people have said and that is that the rule change rendered them noncompetitive.
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  #8  
Old 2 Weeks Ago
Racemaster Racemaster is offline
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Quote:
Originally Posted by syclonedave View Post
How are they different ?
The current Mirror port head is not a Hemi. The old Boss 429 was a rotated Hemi. All the 426 and old 392 stuff are Hemi configuration. Duntov's flathead conversion was a Hemi. Pretty much the intake and exhaust valves oppose each other in a Hemisherical combustion chamber. The currrent Dodge production 6.2 is a Hemi. The old Ford Escort 1.6L I4 CVH was a Hemi. Now it seems as though anytime anyone sees a wide valve cover it is automatically a Hemi. Not always true.
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  #9  
Old 2 Weeks Ago
Mac4264 Mac4264 is offline
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Quote:
Originally Posted by Racemaster View Post
The current Mirror port head is not a Hemi. The old Boss 429 was a rotated Hemi. All the 426 and old 392 stuff are Hemi configuration. Duntov's flathead conversion was a Hemi. Pretty much the intake and exhaust valves oppose each other in a Hemisherical combustion chamber. The currrent Dodge production 6.2 is a Hemi. The old Ford Escort 1.6L I4 CVH was a Hemi. Now it seems as though anytime anyone sees a wide valve cover it is automatically a Hemi. Not always true.
Think everyone has an opinion on what a hemi is. The pro stock version is more vertically inline then the chevy and everyone calls it a twisted wedge head. Which is run funny cause in comp elimnator world a wedge is true in line like a small block chevy or ls1. We always called everything else a canted valve or splayed valve head. This is also how the rule book refers to them as well. The originally hemi from years past had trouble getting compression is why it's down fall came in pro stock. The current version suffers from it's next Achilles heel and that's because the intake valve is in the center or very close of the cylinder and the exiting air doesn't know which way to turn causing a no swirl scenario.
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  #10  
Old 2 Weeks Ago
dragracingfan1 dragracingfan1 is offline
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Quote:
Originally Posted by HEMI_guy View Post
With another 500 rpms it could be as competitive as the rest.

BTW... keep an eye on the Geoff Turk Challenger in the Factory Stock Shoot-out. I had a very intersting talk with him on Sunday. He explained why others have failed at being competitive with Dodges in the class and his theory on why we're not seeing Cobra Jets running in the 7's in legal trim anymore.
There has never been a 7 second run by any legal Stocker. At the Dutch Classic at Maple Grove last year David Barton made the fastest run ever by a legal Stocker in his COPO Camaro at 8.07. At the Maple Grove National Event last year, a week before the Dutch Classic, Chris Holbrook made the fastest run ever by a legal Cobra Jet Stocker at 8.10. I attended both events and witnessed both runs. Maybe the 7 second barrier will be broken at Maple Grove in a few weeks at either the National event or the Dutch, but it certainly hasn't been broken yet. I believe both Carl Tasca and Roy Hill have run in the 7s in illegal trim; maybe that is where the confusion comes from. Both Stephen Bell's COPO Camaro Super Stocker and P.B Candies Cobra Jet Super Stocker have run in the 7s. A couple of years ago Candies made the fastest Super Stock run ever at 7.80@176+ in FSS/A. A week ago, at Indy, I watched him run 7.88@170+ in FGT/B. I agree with you about Geoff Turk; his 8.15 run during Factory Stock Showdown qualifying at Indy was very impressive.
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