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FE Power Forums => FE Technical Forum => Topic started by: Qikbbstang on March 12, 2016, 09:50:59 PM

Title: In days of old there was a brief period when many A/FX Fords ran tall
Post by: Qikbbstang on March 12, 2016, 09:50:59 PM

"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

Title: Re: In days of old there was a brief period when many A/FX Fords ran tall
Post by: falcongeorge on March 13, 2016, 01:04:16 AM

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.

Title: Re: In days of old there was a brief period when many A/FX Fords ran tall
Post by: jayb on March 13, 2016, 08:46:31 AM

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.

Title: Re: In days of old there was a brief period when many A/FX Fords ran tall
Post by: BH107 on March 13, 2016, 12:14:22 PM

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.

Title: Re: In days of old there was a brief period when many A/FX Fords ran tall
Post by: TomP on March 19, 2016, 01:27:44 PM

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.

Title: Re: In days of old there was a brief period when many A/FX Fords ran tall
Post by: Heo on March 19, 2016, 02:19:28 PM

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