Fabbin' a Slingshot intake on the cheap...

[skipstitch]

I've always admired the guys who pioneered speed equiptment. The trial and error must have been rewarding and frustrating all at once. I've been wanting a slingshot style intake for my flathead for a long time and I never seem to have the scratch when one comes up...so... I'm lookin' through one of Don Montgomery's books the other night and the light bulb went off when I spotted an early Edelbrock... And here's what happened 8 hours later. Keep in mind I'm an upholstery guy and I'm sure I'll have to fiddle with the design to get it running right... But that's why it's a hobby!!! First up the supplies.
-Two 94's... one off the flatmotor, the other a pencil holder with no guts
-a piece of 1/4 inch plate steel
-a U-bend of exhaust tubing

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then I made a cardboard pattern of the carb plate, marking center lines for the bolt holes etc... and transfered it to the 1/4" plate. And headed off to the band saw...

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Following that I patterned and cut the intake base plate in the same manner. Here it is test fit on the existing stock intake carb mount....

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After that I test fit for the down tubes... I kept them only 3.5 inches tall so the carbs wouldn't be over my windshield. It also helped in keeping the carbs close together which is the look I am after...

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Here the down tubes are tack welded to the intake plate and I'm test fitting the carb plate for center/level before welding.

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Heres the top of the carb plate with the holes cut above the down tubes.... They are small in this pick, but I didn't have a holesaw the correct size...so I'm gonna open 'em up with a die grinder to get them the same diameter as the tubes....

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The view from the front sittin on the motor... notice how the down tubes stagger to clear one another... figuring that was a bit tricky....

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The money shot http://www.jalopyjournal.com/ubbthreads/images/graemlins/blush.gif The look is just what I was after. All that's left now it final welding and tapping of the top plate to bolt the carbs. The rear carb will supply one side of the stock intake and the front the other.... The best part, it cost about 8 bucks and I can tweak it to make it work....Stitch

[porknbeaner]

Well that just shot my collection of E-Bay stuff down the tubes.

Looks doable friend. Now if we could just figure out how to cast it we'd be rich. http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif

[NorwegianV8]

Looks real good http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif

[continentaljohn]

Cool... great idea http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[hankcash]

WOW!
looks like Tech week has finally kicked in!!
HC

[mr57]

You want to make me one???

[Baron Von Mike]

Very, very cool. But I can't tell from your photos. How hard is it going to be to tighten the stud that goes through this hole? Looks like the stud will endup inside the down-tube, or are my eyes just fooling me?

Thanks,

Mike

[Ryan]

brilliant post...

[JSM56]

awesome.

[Upchuck]

great stuff!

[redpunk]

That RULES....

[slammed]

Can you imagine what this guy could produce if he were to hang/work at one of the 'pro's' shop's for a month or two in fabrication? Dude, you are good.

[Dirty2]

Tooo cool put 2 of these on on a 2 pot intake great!!!

[skipstitch]

Hey Guys...thanks... And Von Mike, I guess in my haste to get all the pics downloaded I failed to mention that. Good eye you have there. You're right, you tighten that bolt inside the tube (I left Plenty of room for the nut and lock washer) and then you bolt the rear carb in place. I won't be shy usin' locktight on that one!!!

I'm thinkin' about havin' a buddy of mine powder coat the thing when I'm finished so I don't have to worry about surface rust inside the tubes... Stitch

[Boones]

how about another shot from a different angle to give a better view of the lower plateform. Great job....

[slammed]

Know anyone with scrap Stainless? Polished up it would be dazzling. Well done.

[BARNETT]

Man, that is unreal! As good as you are with upholstery...you just may have missed your true calling! http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

[cougardan]

Stitch, that is some fine fabricatin' there.

I wonder if you could incorporate some kind of screen in a gasket when you mount it to make sure you don't lose any hardware in the motor. You might use a self locking nut too so you don't have to keep track of the washer? Great job.
Dan

[bufordtjustice]

My hat is off to you, that is freakin cool, very nice job.

Greg

[Killer]

Nice.

Here's a mock up of one of mine.

http://img.photobucket.com/albums/v195/akakiller56/carbadapter01.jpg

[BARNETT]

bttt...this should be on the first page!

[Jeff Norwell]

...Excellant......... http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

[CTFuzz]

Nice job!!....I would re-surface both top and bottom mounting surfaces though, heat tends to warp it.

[Skate Fink]

...makes me want to make one just for the hell of it!! Well done.

[blueskies]

Another thought on coatings the slingshot, how about HPC, JetHot or other ceramic type coating? I had my headers done by HPC, and the finish looks great. They are coated inside and out to prevent rust.

Pete http://home.rmci.net/blueskies/headerscoated.JPG

[kustombuilder]

that is GREAT!!! i too want to make one now just for the hell of it. i LOVE how the tubes cross each other. that looks tricky!!

i agree with the HPC or ceramic coating suggestion. that would look killer. you get my vote...

[fab32]

Shawn. the only problem I see is that you have a 2bl dumping into a single centrally located tube and a down tube dumping into a smaller hole on the mounting flange. This could be a problem with fuel puddling at those two points and causing enough of a distribution bottleneck to make it run irradically. Maybe not but I see some flow issues here. Like you said at the start of this thread, the pioneers started someplace and modified from there. Hope it works out for you.

Frank

[geno_86ed]

Great setup. I am pretty sure this is why the HAMB exists.

A couple ideas/suggestions.

Mandrel bends so there isn't a pinch in the tubes, unless they were needed for clearance.

Widen the upper holes so they match the diameter of the down tubes, I know you said you were going to do this. This is the most critical area for air flow because, in a study of fluid dynamics in an air system an abrupt change from a smaller to larger diameter creates bad air flow and turbulence. There will be "eddies" or back flow and swirl created from the negative pressure this area will create. I know turbulent flow is good for gas attamization in the air, but the air will see a great dynamic pressure head in this area that increases with air flow. Air flows better from a larger to smaller diameter than vice versa.

Do a simple air flow calc to get air velocities in the tubes and play with the diameter of the tubes and see how it affects performace, horse power, torque. $8 in an intake don't cost shit. With your drive and ingenuity we may be buying Stich Speed Parts.

Great job again, these are just points to ponder.

Geno

[flatheadpete]

Oh my goodness....and lot's of it! This is a great idea!! Could be adapted to any motor, any intake, carb, etc. I'm gonna try this one for sure!!

[kustombuilder]

[ QUOTE ]
Great setup. I am pretty sure this is why the HAMB exists.

A couple ideas/suggestions.

Mandrel bends so there isn't a pinch in the tubes, unless they were needed for clearance.

Widen the upper holes so they match the diameter of the down tubes, I know you said you were going to do this. This is the most critical area for air flow because, in a study of fluid dynamics in an air system an abrupt change from a smaller to larger diameter creates bad air flow and turbulence. There will be "eddies" or back flow and swirl created from the negative pressure this area will create. I know turbulent flow is good for gas attamization in the air, but the air will see a great dynamic pressure head in this area that increases with air flow. Air flows better from a larger to smaller diameter than vice versa.

Do a simple air flow calc to get air velocities in the tubes and play with the diameter of the tubes and see how it affects performace, horse power, torque. $8 in an intake don't cost shit. With your drive and ingenuity we may be buying Stich Speed Parts.

Great job again, these are just points to ponder.

Geno

[/ QUOTE ]

ok, you lost me somewhere around "A couple ideas/suggestions"!!! LOL http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[skipstitch]

Thanks for the tech info to ponder!!! I had considered the puddling of fuel on the base plate & ground a valley down about 1/8" to hopefully compensate for the problem... a Low, Low tech solution. As of today, I widened the top holes and created the same valleys to help. I also encountered my first "small" problem. The attached pics will explain... I'm definitely gonna HPC coat it now. I think it will kinda give me that dull polished aluminum look.
Okay the first pic is just another shot of the down tubes and base someone asked for...

[skipstitch]

Here's a shot looking thru the carb base into the top of the tube. I opened the holes up with a die grinder and then ground valleys into the plate under the carb holes. Hopefully to help with flow. It all lined up really well and I'm happy with it except for the next small problem....

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this little notch on the base of both carbs allows a portion of my top holes to be exposed from the base. Part of this is due to how close I was trying to keep the carbs and how short I wanted the tubes to be...

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It will result in about this much of the hole needing to be gone. Not a big deal, but I don't want to weld in a patch. So, I'm gonna whittle out a new top plate at the beginning of the week with the "flat spot" in the holes... Both openings need about the same change....

[skipstitch]

I Guess it's all a learning curve!!! But Stitch Speed & Power does have a ring to it!!!! http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif Oh, BTW, here's the test mule. It's a little way off but should be ready for next season....

[62fairlane]

if it was me I would split the end of your tubes and/or squish them into an oval shape to better line up. a couple oak blocks with the shape needed cut in them (5 min job on a bandsaw) and a little heat and you should be able to press them to the needed shape in a vise ...or just beat them with a hammer and board. if you have to pie cut them you will need a filler and some grinder work. and I think they would look better with a powder finish.

[sodbuster]

Very cool post. I had to dig to find it, I search back thru with the post's with the star's on them in case you were wondering.

Chris

[NealinCA]

Good post. I am curious to see how it runs. I have considered making a similar piece for a F/H 4 bbl intake, as those seem to be fairly easy to come by.

Neal

[Psychobilly Boi]

Wow,

Amazing work...

Danny

[praisethelowered]

I love that you made this thing and now you are sucked into "fluid dynamics" questions. Your attitude is really really inspiring. You build a wierd new thing and problem solve along the way. That's what I call FUN. Seriously - the best post in a while.

[zman]

All the tech to the top...