.....that is absolutely awesome!

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'73 Scamp (the girlfriend): 225ci super/6 2BBL conversion (Almost done!)
'90 Subaru, wagon (the wife): H4-cyl 2.2L

1977 Mercedes-Benz 300D, 5cyl diesel(For sale!)

does anyone know the length of the intake runners on a hyper-pac intake
and the history on how they came up with that length?

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slant six's RULE!
http://www.usajon.com

Heres' The Short Version.. Tom Hoover & crew in the Engine Dyno Room... @ chrysler
They had a carb and Plenum with Adjustable length Runners .. Many pulls..

Results were the 14"(i believe) was the Harmonic / Length that Pulled the air into the cylinders with the Most VE in the most usable range of desired engine operation..

I am sure others will Chime in with more details.. etc.


Greg

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http://www.youtube.com/hyperpack

July 1960 Hot Rod Magazine. Resonant or acoustic tuning effect. There is a chart showing tuned length to RPM, measured from valve head to first pressure disturbance. The artical says with the slant there is a slight resonant effect around 6000 rpm. They also speak about intertia ram which gives a flat torque curve. I think they made the manifold as long as the Valiant inner fenders would accept. My manifold measures around 12 1/2 on the center runners to the plenum and around 13 1/2 on the front runner. The 2nd and 5th runners are somewhere between. It's a good distance from there to the base of the carb. I have seen photos of a frankenstein manifold that has a bolt on plenum that could be tuned easier than casting another design and I have seen an IR Runner design with rubber tubes that could be used to change lenghts. I remember pictures of Pete McNichols Willys had the Frankenstein manifold on it. Must have come out the "back door".

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Hyper_pak

OK
but those motors were 170's
so a larger motor would tune diff. ?
any thoughts here..

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slant six's RULE!
http://www.usajon.com

Well you would pull more air through with the 225 vs 170, but the distance to the head of the valve and plenum would not change. But since the dyno work was done on the 170's it does make you wonder.

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Hyper_pak

OK
every change in an engine would change the flow charestics
displacement/cam specs/comp/head flow
when you look @ early mopar big V8;s they have some very long intake stuff

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slant six's RULE!
http://www.usajon.com

The size of the engine does not make any difference on the length of the manifold runners. Just the rpm where you want the "ram" effect, and the intake lobe timing. Temperature plays a small effect, as the pulse speed will change slightly with a different air temp. You want the positive pressure wave the arrive at the intake valve just before the valve closes. It is not the volumm of air or the speed of the air flow, it is the timing of the pressure waves that make the difference.

If you look at the early 413 cross rams, the runners were very long. If I remember correctly, they were tuned for about 2800 rpm. They were a street car. The Hemi used shorter runners as the were basiclly a race car and wanted the "boost" at a higher rpm.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Sorry for poor detail as these are scans of photo-copies. These are some of the things they were doing early on in the engine program 52 years ago!



Photo credits are as listed.

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Hyper_pak

http://www.chrysler300club.com/uniq/all ... trams.html

I knew there was 2 different lengths.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

I was not aware of the two different lengths on the wedge engines. In that article, it makes referance to the cam timing, as I mentioned.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

You learn someting everyt day.. Yay Ram engines.. Including the Hyperpacked Slants..

I will have to keep an eye out for the long and short rams at the next mopar show.


Greg

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http://www.youtube.com/hyperpack

I have a friend who drives and nastalgia races a 451 low deck with the long rams. 452 MP alloy heads TTI's and 2 625 AFB's. The intakes will fit B or RB engines. Last I heard he was in the high 12's in a 4 door 1960 Fury.

In reality our slants have 1bbl ram type intakes. Wasn't hat one of the reasons to lean the block?

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

No, they were slanted over for packaging reasons. A long stroke six cylinder wouldn't fit under the '60 Lancer's hood. Since it was slanted over, the engine people had more freedom designing the manifolds.

The '60 which, now?

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