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what a craftsman!!


btw... with these, you could get rich... for all those carburators
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Originally Posted by Discseven View Post
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Old 08-31-2017, 04:58 AM
  Pelican Parts Technical Article Directory    Reply With Quote #81 (permalink)
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I continue to be amazed! It's practically art!
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Old 08-31-2017, 01:58 PM
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Quote:
Originally Posted by kuehl View Post
Uncle Karl,

Anemometers... depending on the diameter of the device's (meter's) wheel (blade), speed will vary depending upon the location, angle and distance from the source.

Please show the formula for cfm based on 23 mph through 4" ID.
For some reason my 1 cup of coffee calculator keeps coming up with a lower number, like 176 cfm?
A 12" nominal 'spal' type fan typically moves about 850 cfm at 0 static; 13 vdc.

Otherwise, nice craftsmanship and creative work, love it!
Agree.

23mph is 2024 fpm

4 inch ID duct area is PI X 1/6 X 1/6 = 0.0872 ( sq ft )

2024 X 0.0872 = 176.6. CFM
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Old 08-31-2017, 02:01 PM
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Agreed.

But, its truly amazing watching Uncle Karl at work when he takes on a project.
Broad range of materials, processes, art and craft.
I'd hire him but know I can't afford more than 1 six pack a day.
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Old 08-31-2017, 02:09 PM
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+1.

It also illustrates how much time and effort goes into R&D which is good for people to understand why certain products cost what they do.

Karl, second job offer here, 2 six packs a day*

*not to be consumed in office hours.
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Old 08-31-2017, 02:15 PM
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1 six pack a day, can be consumed during working hours. Don't want the
boy to dehydrate.

AND


1 fifth of Pappy Van Winkle’s Family Reserve 20 Year per week.
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Old 08-31-2017, 02:48 PM
  Pelican Parts Technical Article Directory    Reply With Quote #86 (permalink)
Knee Pads are Overrated!
 
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Will either of you two potential employers require that KinkyKarl utilize his car's custom diaper when parked on your premises, or can it (and he ) go commando?!?!
Old 08-31-2017, 10:21 PM
  Pelican Parts Technical Article Directory    Reply With Quote #87 (permalink)
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Quote:
Originally Posted by kuehl View Post
1 six pack a day, can be consumed during working hours. Don't want the
boy to dehydrate.

AND


1 fifth of Pappy Van Winkle’s Family Reserve 20 Year per week.
PM sent with resume.
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Old 09-01-2017, 04:33 AM
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Quote:
Originally Posted by kuehl View Post
Uncle Karl,

Anemometers... depending on the diameter of the device's (meter's) wheel (blade), speed will vary depending upon the location, angle and distance from the source.

Please show the formula for cfm based on 23 mph through 4" ID.
For some reason my 1 cup of coffee calculator keeps coming up with a lower number, like 176 cfm?
A 12" nominal 'spal' type fan typically moves about 850 cfm at 0 static; 13 vdc.

Otherwise, nice craftsmanship and creative work, love it!
Charlie... agreed on anemometer reading's fluctuation. Point of using it here was to get some idea of what's going on. My CFM math...
Area of circle = PI x radius squared
Area of 4” diameter circle = 12.56637 ”
Area per linear foot of 4” duct: 12.56637 x 12 = 150.79644 cubic inches
1 sq. ft. = 144 cubic inches
Square footage per 1’ of 4” duct = 150.79644 / 144 = 1.0471975 ’
1 mile = 5,280 linear feet
Square footage inside 1 mile of 4” duct = 5,280 x 1.0471975 = 5,529.2028 sq. ft.
In 1 hour, 1 mile of 4” duct has capacity to pass 5,529.2028 cubic feet of air
1 Minute translation = 5,529.2028 / 60 = 92.15338
“CFM” in 4” duct = 92.15338 per mph
According to above...
23 mph = 2,119.52774 CFM (Not sure how I arrived at 2,184 as previously noted.)
26.5 mph = 2,442.06457
49.8 mph = 4,589.23832
Compliment appreciated from ya in the JerseyLand! Was in Manhattan last week. Thought about truckin over to visit you but couldn't manage. Will come by at some point to see what you're really up to.
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Prior: '74 Carrera. '79 Silver 930. '79 Black 930.
Old 09-01-2017, 05:21 AM
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Quote:
Originally Posted by Discseven View Post

23 mph = 2,119.52774 CFM (Not sure how I arrived at 2,184 as previously noted.)
26.5 mph = 2,442.06457
49.8 mph = 4,589.23832
Compliment appreciated from ya in the JerseyLand! Was in Manhattan last week. Thought about truckin over to visit you but couldn't manage. Will come by at some point to see what you're really up to.
Nope. You can find a simpler equation just using Velocity (ftpm,mph,knots, etc) and diameter. You could toss in other density variables (mass; temp, humidity) but keep it simple.

"Reallys".... still trying to the tune AEM enginemanagment system on the supercharged 911. Almost had it right but VE tables max'd out cause of small injectors (math problems, lol). However, my new 50,000 mile (flight miles) Callaway Epic driver is so much fun. Staying in the fairway 85% of the time, 220 to 260 yards. And, I am finally a believer of in the Titleist Pro V1. No more searching for used balls in the woods !

Keep plugging away on your Bucket Project, you never know, it could be better than a simple spal fan. If not, I can think of a few applications you and innovate the work over too. But don't try this Busted
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Old 09-01-2017, 06:27 AM
  Pelican Parts Technical Article Directory    Reply With Quote #90 (permalink)
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^^^^^ Flo, Dave, Jonny... thanks for positive vibes guys! Skal to yas all!

Six pac compensation from hood-bros is appealing. Progress does slow based on during-work-hours consumption. How much... don't know... math-ability is currently under scrutiny. Bobster, nice of you to send resume in my sted. You're far better than I at drinking & fab'ing at same time!

Funny that you recall "diaper" RonO! That was temporary condo BS to accommodate. Management is now focused on other things so diaper is relegated to storage (until management refocuses on garage floor.) I have can of brake cleaner on hand to swab deck when oil slick goes Valdez.

Dave... art? Yeah. I approach this stuff as sculpture. Adds valued dimension to endeavor so build here is much more than just making Porsche AC parts.


Door landing



Landing profile. Is cut out of 0.06” thick gasket rubber. (Variety of challenges and sorting through solution-options makes this a constant discovery-journey... with smaller bits typically more enlightening to deal with than larger ones.)




Here, thin rubber strip needs to get into a relatively exact position with adhesive applied to one side without making a mess of things and, given gel epoxy, there’s 3 minutes to do it. After playing around with a few approach ideas... am finally using paper inside tube as a butt-to. Scrib'ing a line is possibility but believe that path would have turned messy on me.




Torsion spring test

Was guestimate what spring to go with. Chose heavier option. With bull-horn bent into it… decided only 1 spring was necessary. If there wasn’t enough torsion, would cut back on spacers on mandrel and add another spring or two. Turns out heavier spring is too much---doors don't begin to open until intake is almost fully blocked. Removed heavier spring and installed lighter spring with bull-horn bend… doors opening too early. Increased bull-bend and here's what's happening…




Zero intake obstruction. Wondered if doors would whistle given air passages around spring area. No whistling.




¼ Intake obstruction.




½ Obstruction.




¾ Obstruction




Fully blocked.

Doors can open to point of laying against each other. In other words there’s more air passage potentially available when main intake is fully blocked. Am thinking torsion in spring installed here is increasing too much as spring turns. Perhaps more coils would offer less increase in torsion as spring turns. Will check later today if Gardner has same spring with more coils. If not, will go with this. EDIT: Checked and there are 6 colis but with 1/2" legs. Shorter leg than what's in use seems moot move-to.

Why use 3” O.D. for valve duct? Serves as an alarm of sorts---premise being a narrower air passage should sound differently than 4” main intake. It does. When valve opens, is a higher pitched wooshing sound compared to main intake sound. Space is also factor. Where air-valve's now positioned on intake stack there used to be a duct spacer. That spacer is now removed so valve takes its space.

90 degree inlet bend. Is questionable how inlet will fit in wheel well… plan being to point inlet to tub wall or to fender. This pointing plan requires more width than stack as 90 degree sticks out beyond width of 4" wide stack. Pointing inlet up or down is not appealing for various reasons. Will see if this is problem-to-solve when installing cradle-bracket for stack. Thought about using cobra inlet but that appears to take up too much linear space---it would get too close to or possibly enter tire's space. In retro-spec, foil-casting entire wheel well would have allowed these sort of fit questions to be answered instantly with actual measures rather than from "mental recall of space." Is hindsight working here---casting entire wheel well early-on in project would not have made sense.

Credit to Coastr for system having an air-valve.
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Karl ~

Current: '80 Silver Targa w /'85 3.2, '79 Anthracite 930
Prior: '74 Carrera. '79 Silver 930. '79 Black 930.

Last edited by Discseven; 09-02-2017 at 03:22 PM.. Reason: Checked torsion spring with more coils and credit to Coastr
Old 09-01-2017, 06:53 AM
  Pelican Parts Technical Article Directory    Reply With Quote #91 (permalink)
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Karl at this point in the project you need to go back all the way to Post #1 on this thread and document your write up in a long form narrative document. There is some serious R & D here that can be used in several simular types of applications. I'd even consider getting a Patent.
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Old 09-01-2017, 07:38 AM
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Found error---way I see a "square foot" it's a cube. Therein's my downfall. So instead of 144 the number should be 1728. You guys are correct... I'm wrong. Will go back and make note of it.

Difference in CFM is downer... but is it enough to kill project at this stage? Is definitely sufficient enough to cause a pause-and-rethink moment.

Charlie, Jonny... thanks for reality check guys!
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Prior: '74 Carrera. '79 Silver 930. '79 Black 930.
Old 09-01-2017, 08:38 AM
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Quote:
Originally Posted by RNajarian View Post
Karl at this point in the project you need to go back all the way to Post #1 on this thread and document your write up in a long form narrative document. There is some serious R & D here that can be used in several simular types of applications. I'd even consider getting a Patent.
Raff... am contemplating air temp difference delivered to condenser if that's what you're alluding to. Concerning R&D, is much pleasure to hunt for intell and sort things out. Fortunately I have you and the rest of the crew here helping out---I never see these projects as mine. It's everyone's who wants to participate. In explorations like this I expect highs and lows. The CFM enlightenment is a let down of sorts but not a defeat. Is opportunity for more creative.

Patent suggestion implies a compliment which is appreciated. If you want to initiate moving in that direction, I'd explore it with you. To do it myself, I candidly enjoy what's already on my plate (but would alter course with the right enthusiasm pushing in a given direction.)
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Old 09-01-2017, 09:06 AM
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Quote:
Originally Posted by Discseven View Post
Found error---way I see a "square foot" it's a cube. Therein's my downfall. So instead of 144 the number should be 1728. You guys are correct... I'm wrong. Will go back and make note of it.

Difference in CFM is downer... but is it enough to kill project at this stage? Is definitely sufficient enough to cause a pause-and-rethink moment.

Charlie, Jonny... thanks for reality check guys!
No problem Uncle Karl.

CFM... its gonna be what its gonna be. You can always revert to my previous offer
on the original serpentine with Spal so at least you'll have good AC in the warm months... after you complete this cause we want to see the fat woman sing. Simply too much anticipation with the project.
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Old 09-01-2017, 11:35 AM
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Originally Posted by kuehl View Post
You can always revert to my previous offer on the original serpentine with Spal so at least you'll have good AC in the warm months... after you complete this cause we want to see the fat woman sing.
Appreciate you keeping offer tabled! ...You da-man---TY! Not throwing towel in yet. This thing still has air-temp legs. Am pondering CFM at moment. (You know me... my projects can span years and hundreds of posts. This thread... just a youngster.)
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Old 09-01-2017, 02:23 PM
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Do you have, like, a target CFM or just the more the merrier? How much does pressure matter?

This 6" fan is a 700 CFM monster:

https://www.americanvolt.com/collections/6-inch-fans/products/6-inch-small-slim-electric-fan-12v-radiator-oil-cooler-atv-mini-tractor-mower
Old 09-01-2017, 03:14 PM
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Quote:
Originally Posted by Discseven View Post
Am pondering CFM at moment.

In simple terms:

A 12" nominal fan covers 113 square inches.
A 4" nominal fan covers 12.5 square inches.

The 12" direct mounted fan is moving 850 cfm in total over the 113 square inches.
Each square inch gets 7.5 cfm

The 4" in-direct mounted fan is moving 176 cfm over a total of 12.5 square inches.
Each square inch gets 14.08 cfm

The small 4" in-direct fan device is delivering more air per square inch, twice as much.

Take the smaller 4" fan’s 176 cfm and move it across 113 square inches
and each square inch gets 1.5 cfm. That 80% less than what the 12" direct mount fan offers.

The 12" direct mount fan has nearly zero static pressure loss when the air meets the surface to be cooled.
The 4" ducted fan’s static pressure loss where it meets the surface to be cooled needs to be measured.

Some blower or fan designs and hold up quite well against static pressures.

So, ignore all that for moment, complete the project, and see what it yields in terms of CFM, MPH, or FPM, or Knots or whatever per square inch existing the condenser.

Many inventions are not the direct result of what you intended them for.
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Old 09-01-2017, 04:15 PM
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Quote:
Originally Posted by Jonny H View Post
Agree.

23mph is 2024 fpm

4 inch ID duct area is PI X 1/6 X 1/6 = 0.0872 ( sq ft )

2024 X 0.0872 = 176.6. CFM

I believe your equation assumes a constant velocity across the 4" duct. This is not going to be the case, on the sides of the duct the velocity is zero. The velocity profile along the radius of the duct depends on a number of things e.g. Reynolds number/etc.
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Old 09-01-2017, 04:30 PM
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Quote:
Originally Posted by hcoles View Post
I believe your equation assumes a constant velocity across the 4" duct. This is not going to be the case, on the sides of the duct the velocity is zero. The velocity profile along the radius of the duct depends on a number of things e.g. Reynolds number/etc.
Here is a picture that might help.



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Old 09-01-2017, 04:33 PM
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