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Greg Myers

Little Known Car Facts #3, "Cut Outs" not to be confused with "Lakes Pipes"

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Good to make that distinction. Course, you can always bolt your cutouts or dumps to side or lakes pipes, and then it gets really confusing from a pure-definition standpoint. :D

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Lot's of variety here. The one in the second picture is what I remember. I also remember them being called "dumps" or "plugs". I always thought the ones with the cable would be fun. Sometimes you just want to make noise!!! Especially when you are young. I still like open headers and high octane fumes even now that I am old. ;)

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But wait, there's more . . . now with electricity , controlled right from your very own dash. Fun, Fun, Fun B)21d1160592542-dmh-exhaust-cutout-dmhcuto

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MaxWedgeHpipe-600x600.png these were actually a factory setup on the mid sixties Max Wedge cars. :o

Edited by Greg Myers

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We called them dumps and / or cut outs, they can be found in the old Almquist and JC Whitney catalogs, even the electric varieties.

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Greg...I'm really curious about those headers in post #7. They defy everything I ever learned about equal primary-pipe length, bringing primaries in to a collector, length and diameter of collector, and one pair of primaries is actually behind the crossover, etc.

Granted, I haven't actually designed a set of headers in over 10 years, but either the science has changed considerably since then (and I no longer know what I'm doing) or the designer of these headers doesn't have a clue.

So, please sir, what's the story behind these?

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What MOPAR really got away with was calling them "Cast iron" exhaust manifolds due to the short "cast" piece bolted to the engine, Tube headers being better than any that were cast,hemidualcarb-vi.jpg

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An interesting aside, these steel tube headers are found in many JoHan HEMI kits. Wedge engines only, not HEMI.cross-ram.jpg

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Greg, what I'm getting at is that there are two pretty much universally accepted "correct" header/collector designs for a group of 4 cylinders. 4 into 1, or 2 into 2 into 1 (sometimes called "tri-Y")

4 into 1... dljmyo.jpg

2 into 2 into 1 ... ("tri-Y") 4-2-1-headers-281x300.jpg

There an infinite number of variations on the two themes, but neither bears the slightest resemblance to the primary pipe / collector arrangement on the setup in post #7.

Do you know if they were a dyno-developed odd resonance-in-the-collector system, or just a way to get more ground clearance ?

I've read extensively on header design, and the post #7 units look more like '30s through '50s ideas of acceptable gas flow than any later designs I'm familiar with. The idea behind "equal-length" primary pipes, and making them enter the collector at the same point, has to do with exhaust pulses in one pipe partially scavenging the adjacent pipe...which wouldn't happen in the accepted sense with the way the primaries are spaced out along the collectors in post #7. That's why I'm wondering if these were a one-shot dyno-developed system that flies in the face of conventional wisdom; you know, if it works, it works, and screw the theory (which was, by the way, entirely developed using dynomometers and empirical observation).

Edited by Ace-Garageguy

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According to an article in the April 1964 edition of Hot Rod magazine by Ray Brock, the primaries were 44" and connected into the larger pipe acting as a collector( referred to in the article as "collector pipes")6096483-7-20-1064HOTRODMag001.jpg The NASCAR headers did not have the cross over "H" pipe, this was only used on the drag cars. As for dyno testing, something must have come up as these were only used the first year ,1964.

Edited by Greg Myers

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Thank you Greg. Absolutely fascinating exhaust system. I'm going to see if there's an old SAE paper on that thing. There may not be if it was an in-house "secret weapon" design, but then again, if it worked or not, there may very well be a paper about its development. It sure is different.

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On 8/30/2014 at 4:42 PM, weasel said:

we called them 'dumps'....

Back in the 60's some "cut outs" went all the way to behind the front tire with a removable cap over the flange. We used to call them "lake plugs."

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