Author Topic: In days of old there was a brief period when many A/FX Fords ran tall  (Read 2922 times)

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Qikbbstang

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"ram tubes"  on both SOHC's and Wedges. I've always thought they were really cool looking and believe Injected and Blown A/FX's both ran nitro.

I copied this from an article PDF I linked below:
"Going into that year’s NHRA Nationals, the injected cars could run times between 7.90 and 8.00
with relative consistency, and the supercharged cars were still imbedded in the 8.20 to 8.30 range."

(1) I'd like to know the reason(s) tall fuel injection stacks use was so short lived in A/FX?.......
(2) what is the reason(s) for the super long length?
(3) How come no-one seems to mess with Ram Tubes at events like Drag Week?
I think they still run tall FI stacks in Sprint Cars...
http://www.conceptcarz.com/view/photo/579813,15659,0,0/photo.aspx

http://www.conceptcarz.com/view/photo/579815,15659,0,0/photo.aspx

http://www.nhra.com/userfiles/file/NDLiveFiles/Features/FCInnov.pdf
« Last Edit: March 12, 2016, 09:55:17 PM by Qikbbstang »

falcongeorge

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lengthening or shortening the tubes will lower or increase the rpm peak torque occurs at. Somewhat of an over-simplification, but lengthening the intake tract, increases the time interval between harmonic waves in the intake tract.
« Last Edit: March 13, 2016, 01:06:27 AM by falcongeorge »

jayb

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Guessing here, but the tall stacks will tend to bias the power curve to a lower RPM, so maybe the old A/FX cars needed more power down low, due to the clutches.  Maybe when slipper clutches came along they were able to use the power in the upper ranges better, and the stacks go shorter?  Sprint cars need the lower end grunt coming out of the corners, so that is probably why you still see the long tubes in use there.

I ran ram tubes on my Galaxie in 2008 and 2009 at Drag Week, and this year the guy who finished third in my class ran them on an SBC.  So its not like nobody runs them, they just aren't as popular as they used to be.  They are a lot more difficult to set up than a pair of carbs on a tunnel ram.
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

BH107

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I was looking through an old 60s injection book a few months back from a Hilborn distributor. It stated that the long tubes were better suited for autos, and short tubes for 4 speeds.

TomP

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Though look at the NHRA A/ND class. All are slushbox by the rules and some have no tubes at all with the butterflies barely clearing the head ports. It almost looks like one of Jay's adapters without a Cleveland intake at all.

Heo

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A friend had a dragboat with Kinsler FI with
maby 6 inches long tubes .He put the engine
in 27 roadster Drag car with auto And i shorted
the tubes  down on Kinslers recomendations
 to just the "bells",Dont remember
the final lenght
To take some torque out of it
But that engine had 1000 lbs/feet torque with
long tubes. Was never dynoed with short tubes
They grenaded 3 powerglides in a row and gave up
« Last Edit: March 19, 2016, 02:43:59 PM by Heo »



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