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Current Page: 9 of 13
Re: My New Fan!!
Posted by: john.jackson ()
Date: May 17, 2019 03:52AM

63turbo Wrote:
-------------------------------------------------------
> I thought I would update this thread a little, as I have been able to get some testing in. The Nashfan has hit a new pressure record!! The old peak was 13.67"@ 5250 engine rpm, and was done with the airflow pulley and "short" bellmouth. Since that test was done, I started testing a taller bell last fall, and was kind of disappointed with it then, as it seemed like I had run into some sort of weird pressure vs flow trade... the pressures at elevated rpms seemed down compared to the "short" bell, but it was impossible to test this bell properly until it was hot enough.
> Conditions were ideal last week to test the big bell! 14.67" @ roughly 6000 rpm, and 13.67" @ 5500. The pressure kept building and was not giving me any signs of stalling at 6k,,, I just wasn't going to rev it higher!
> This was an interesting test for a couple of reasons. One is that the taller bell does seem to slightly reduce the pressure at a given rpm (it took 250 more rpm to equal the pressure of the short bell), but does extend the rpm range. I believe that this might be caused by the cross over manifold becoming a blockage as the bell gets taller, and might not do that on an NA car. The other interesting observation was that the pressure at idle after this test was done was down to .41" at 1000 rpm, and when the fan laws are extrapolated from .41" @1000 engine rpm out to 6000 rpm, you are supposed to get roughly 14.6", indicating that belt slippage still hasn't become a problem!!
> This test, like the previous tests last summer were done with the restrictive lower shrouds installed, and the estimated flow for this test would be around 1900 cfm. My estimate for flow without the lower shrouds on would be around 2660cfm, and this would be enough to properly cool most cars at 250hp or less.
> The early adopter fans should be capable of 2873cfm set-up like that!!!

Kevin,

Sorry for the stupid question. But any comparison to stock air flow?

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Re: My New Fan!!
Posted by: American Mel ()
Date: May 17, 2019 08:19AM

Dave, and John, both of your questions are addressed in the earlier pages of this thread.

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, '62 Monza Wagon, '63 Spyder, '65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dualy, approaching 400K
17'Terry

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Re: My New Fan!!
Posted by: DaveO90s4 ()
Date: May 17, 2019 02:20PM

Sorry - I must have missed that. Or forgotten!! I’ll go back and reread.

Thanks

DaveO

Dave O

1975 Porsche 914 with 140 HP Corvair reverse rotation engine, zenith 40 TINS, Otto 20 (or 30?) cam, etc, Australia



Edited 1 time(s). Last edit at 05/17/2019 02:29PM by DaveO90s4.

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Re: My New Fan!!
Posted by: DaveO90s4 ()
Date: May 17, 2019 04:11PM

OK - I just reread the 9 page thread - and this time I think I now much better appreciate the ‘air-pulley’ and what that is allowing air to do. Ie enter the system closer in to the hub, thus increasing the ‘effective’ length (the ‘working’ length) of the vanes. Since this has made such a significant improvement are there other ‘tweaks’ that could be done in this critical area?

Could the flat top surface of the pulley be shaped to feed air into the air pulley voids with less transition?

Could a spinner / nose cone atop the flat bearing help with airflow entering into the pulley voids? (A bit like the Porsche engine image that Matt posted).

Could the leading edge of the pulley voids be angled to improve airflow / reduce turbulence of entering air? (Rather than the vertical face that it currently presents to entering air?


Just some thoughts - that may well have been already thought through and rejected. Great work Kevin (both the thought that’s gone into it and the engineering outcome).

Cheers

Dave O

1975 Porsche 914 with 140 HP Corvair reverse rotation engine, zenith 40 TINS, Otto 20 (or 30?) cam, etc, Australia



Edited 1 time(s). Last edit at 05/17/2019 04:13PM by DaveO90s4.

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Re: My New Fan!!
Posted by: DaveO90s4 ()
Date: May 17, 2019 04:44PM

^^^^signficant. (Typing this on an iphone - not rasy!)

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Re: My New Fan!!
Posted by: MattNall ()
Date: May 17, 2019 05:53PM

DaveO90s4 Wrote:
-------------------------------------------------------
> ^^^^signficant. (Typing this on an iphone - not easy!)

=================================================

Surely you can speak instead???

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: My New Fan!!
Posted by: 63turbo ()
Date: May 17, 2019 06:17PM

DaveO90s4 Wrote:
-------------------------------------------------------
> OK - I just reread the 9 page thread - and this time I think I now much better appreciate the ‘air-pulley’ and what that is allowing air to do. Ie enter the system closer in to the hub, thus increasing the ‘effective’ length (the ‘working’ length) of the vanes. Since this has made such a significant improvement are there other ‘tweaks’ that could be done in this critical area?



Yes there are tweaks and they have been made! The "underside" of my as tested pulley isn't nearly as good as it could have been... Ideally this would have had a nearly constant clearance from the base of the fan, but wasn't going to happen with my prototype fan because I had not considered this idea at the time I originally designed the fan... consequently the underside of the pulley turns away from the fan way too fast, and the fan is way too steep in this area. Both of those issues have been corrected on the early adopter versions, as they were designed to work with each other. Also, for much of the same reason, the hub on my prototype had the wrong arc to work as well as it could. Both the fan, pulley and hub have a MUCH smoother, better arc on the early adopter version.
>
> Could the flat top surface of the pulley be shaped to feed air into the air pulley voids with less transition?

There is an intentional arc built into the top of pulley, it is hard to see it but it is there... it would have been additionally helpful to put larger radii into the corners of the openings, but this is extremely difficult to do on a manual machine, like I had to do it, so I left these important fillets out on my prototype- the production version of this pulley has these fillets!
>
> Could a spinner / nose cone atop the flat bearing help with airflow entering into the pulley voids? (A bit like the Porsche engine image that Matt posted).

A spinner/nose cone on top of the flat bearing can easily be put on if it is one of Ray Sedmans replaceable bearing cartidge's, however, because of Matt Nall's experiments with and without a spinner and with and without a fan pulley(!), I would say that it wouldn't help unless the intake airspeed gets up over 100 mi/hr. In Matts test's, he was able to increase the airflow through the fan by 30% without a fan pulley on. This is EXACTLY the amount he should have been able to get just from the area increase! Make no mistake this is a MONSTER increase in airflow, but the area is the area of the O.D. of the pulley minus the area of the flat spot in the center of the fan. He had tried this experiment with and without a nose cone, and saw no change. The reason this happens is that the incoming air "senses" which way to go, well away from any obstruction when it is still moving fairly slowly... because of this effect, a flat surface is just as efficient an entry as a rounded cone shape. Any benefit from a rounded nose cone would come from really high airspeeds, when there's less time for the air to "decide" which way to go.
>
> Could the leading edge of the pulley voids be angled to improve airflow / reduce turbulence of entering air? (Rather than the vertical face that it currently presents to entering air?

They should have had much more rounded edges, I couldn't put them in for my prototype, but are in on the production ones
>
>
> Just some thoughts - that may well have been already thought through and rejected. Great work Kevin (both the thought that’s gone into it and the engineering outcome).
>
> Cheers

Thanks Dave!!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: My New Fan!!
Posted by: 63turbo ()
Date: May 17, 2019 08:22PM

> Sorry for the stupid question. But any comparison to stock air flow?


I tried to compare my fan to stock earlier in this thread, but it is really seriously hard to compare the 2, and here is why:

My fan keeps building pressure way past the point that the stock fan ceases to be an effective air mover. Basically the stock fan is "done" past 5000 rpm.
GM numbers for the mag fan say 1750cfm, and I think the pressure is 12-12.5,
but these tests are done cold, my tests have all been done hot. My own tests with the stock fan showed a phenomenal loss in pressure when tested hot, and nearly all of the pressure loss due to head heating is happening at high rpm.
assuming the measured pressure for my fan tested hot "translates" to the cold pressure and cfm done with the stock fan, then the flow for my fan would be roughly 1850 cfm @13.67" at 5250 rpm (with the small bell), and 1900 cfm @ 14.67" @ 6000 engine rpm with the taller bell. This comparison itself is very misleading, because it assumes that both fans are cooling the engine equally well at the airflow they are able to supply, and this is a really bad assumption! The stock fan at these elevated rpms is literally "beating the hell" out of the air so much from inefficiency that it is HEATING the cooling air before it enters the engine... this heating effect by itself might be as much as 50-60 degrees, and for my fan, this heating might only be 20 degrees or less, at its peak observed pressure! It does not need to flow as much to cool better just because of that effect. The comparisons are even more messed up when considering the total pressure for the fan system. Total pressure is the sum of the static pressure and the velocity pressure. In my fan tests on my test fixture, I found that there was zero difference in velocity pressure and static pressure for my fan when running at a constant rpm. For the stock fan however, this relationship was way different! the velocity pressure was consistently 15% less than the static pressure at the same rpm. I did this set of tests twice for both fans, with exactly the same fan to shroud clearance, the numbers were exactly the same. If this sort of relationship holds up at the rpms that I've tested my fan to, I get a total pressure of 29.34" (!!!!!)
for my fan, and something like 11.5+9.78= 21.28" for the stock fan- this is a 38% increase in total pressure which is a phenomenal increase in pressure, and is something like an 17-18% increase in flow on a "total pressure" basis.
The other reason that the comparisons are hard to make, is that the hp usage between my fan and stock is so exaggerated- this is important because if the 2 fans had equal hp usage, then minor flow differences could be made up by using a taller fan pulley ratio. Since theres such a huge difference in hp consumption, a neat way to really compare outputs is to gear down the stock fan to the point of approximately equal hp usage at say 5k engine rpm... for the stock fan to come close, it would be run at 1.2:1 fan pulley ratio and would be using 7.5 hp, while mine would be around 6 at the same engine rpm with the stock pulley ratio of 1.58:1. Based on the pulley ratio differences, the stock fan down 24% on flow, and roughly 54% down on "static" pressure.
Then theres the issue of taking the lower shrouds off- this is apparently a large increase in airflow- I estimate this is something like a 40% increase in flow, but, because of the differences in fan properties, the stock fan increases its already exorbitant hp usage when run like this, my fan GOES THE OTHER WAY and drops its hp usage.
In summary, because of the enormous differences in fan properties, no, they cant be compared very well, but I tried!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: My New Fan!!
Posted by: playerpage ()
Date: May 17, 2019 08:37PM

Bottom line:

Is the fan useful as an alternative and is it available to purchase?

____________________________________________

Eric C. Player, Porterville, CA
Member: CORSA National, Central Coast CORSA, South Coast CORSA, and San Joaquin Valley Corvair Club
THEN: 1965 Monza 110 Canary Yellow
1967 Monza 140 Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo; nicknamed "Bluvair"

"It would not have helped if I had [taken notes], as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

------

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Re: My New Fan!!
Posted by: 63turbo ()
Date: May 17, 2019 08:53PM

playerpage Wrote:
-------------------------------------------------------
> Bottom line:
>
> Is the fan useful as an alternative and is it available to purchase?


Hell yes to #1, and no to #2 for now, as it is way past the deadline for the billet fan run. The billet fan run is the only way to purchase one of these fans right now, and we have taken all we can take for that.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: My New Fan!!
Posted by: scottymac ()
Date: May 18, 2019 08:40PM

Thought this would put the price for Kevin's fan in perspective. Hope his testing goes well, and will be available to more owners soon.

[www.baileycarsnorthamerica.com]

Scott
Danville, In.
'65 Corsa basket case
'66 Monza coupe

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Re: My New Fan!!
Posted by: joelsplace ()
Date: May 18, 2019 10:24PM

But that one comes with an alternator.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: My New Fan!!
Posted by: CORSATURBO65 ()
Date: August 16, 2019 05:56AM

Hello Kevin:

I have read through 9 pages of postings but have not seen any real clear definitive explanation of the expected or anticipated physical differences between the initially produced heavier [as identified by you as exceeding your weight target] billet aluminum fan, and what is being repeatedly referred to as a "production fan". Which I assume will be optimized in many ways versus the machined billet prototypes.

Is the "production fan" going to be machined or manufactured using a fundamentally different process altogether?

Can you please offer us a "simple summary description" of how the "production fan" will differ [physical appearance, finish/coating, weight, anticipated performance gains, etc;] from the initially produced heavier billet aluminum fan.

CORSATURBO65
RICH FITZ

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Re: My New Fan!!
Posted by: dryenko ()
Date: August 16, 2019 06:35AM

From page one :
" Roughly 2 lbs... If the shop had been able to cut it right exactly to the CAD model, it would have weighed 1.4 lbs- I think the Mag fan weighs 1.3 lbs. I'm not complaining at all- this is a prototype, and is perfect as is for testing.
It would have been nice to get it lighter, but I'm not too concerned about that at this time "
The gains in testing have been spelled out in the subsequent posts....
Anticipated performance gains as well.

Bob C aka Dryenko
Dobson, NC 27017

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Re: My New Fan!!
Posted by: playerpage ()
Date: August 16, 2019 08:22AM

I just want to know when it comes on the market!

____________________________________________

Eric C. Player, Porterville, CA
Member: CORSA National, Central Coast CORSA, South Coast CORSA, and San Joaquin Valley Corvair Club
THEN: 1965 Monza 110 Canary Yellow
1967 Monza 140 Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo; nicknamed "Bluvair"

"It would not have helped if I had [taken notes], as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

------

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Re: My New Fan!!
Posted by: 63turbo ()
Date: August 17, 2019 02:03PM

>
> Is the "production fan" going to be machined or manufactured using a fundamentally different process altogether?
>
> Can you please offer us a "simple summary description" of how the "production fan" will differ [physical appearance, finish/coating, weight, anticipated performance gains, etc;] from the initially produced heavier billet aluminum fan.
>
> CORSATURBO65
> RICH FITZ

The simple summary of how the production fan will be different from the ones that are being produced right now:

1. finish: this part depends on which production technique works out for production quantities... If the hard, high pressure, high temp mold is used,
the finish will be roughly the same as the mag fan, and if one of the newer, "high strength" magnesium alloys is used, the weight of the fan will be the same or less than a cut down mag fan, approx. .8 to .9 lbs, this is because the wall thickness can be less than it is with the mag fan and end up stronger!
If high speed machining is used, then the finish will be the same as the fans that are being made now. These fans are expected to weigh 1.5- 1.6lbs.

2. Output and performance: The fans being produced should have 8-13% more output than my initial prototype fan, and should be in the 10+" range at 4000 rpm and 13-14" at 5000 rpm when the engine is hot... this is a huge increase in pressure over what the stock fans do when the heads are hot.
with the stock pulley ratio, the hp usage for these fans will be something like 3.5 hp at 4k and 6.5 to 7 at 5k.... this kind of hp usage is what the mag fan does when the damper doors are shut and fan not flowing.

I feel compelled to talk about this "weight issue"... as someone that has, by far the heaviest version of this fan, I can tell you all for certain that with my heavy but efficient fan seriously out accelerates the light and inefficient mag fan when the belt is tensioned enough to only support its much lower steady state torque requirements, which is a bit less at 5000 engine rpm, than the mag fan steady state torque requirements at 4000 engine rpm. I remember what the mag fan felt like when the belt came off once...the power increase felt incredible. During some high rpm testing with the Nashfan, I decided it would be a good idea to replace my well worn, "old reliable" fan belt with a new one and rolled it a few times and then managed to break the effing thing at something like 5000-5500 engine rpm. Honestly, it was seriously difficult to "feel" anything, other than a "slight" pick up in engine power, and then I saw the gen light came on and that was how I knew something had happened to the belt. It was NOT at all obvious like when the mag fan was on.
The easy cure for "fan inertia" is to use proper tensioning for the fan, allowing the belt to slip a little when accelerating, and not slipping in steady state, this kind of tensioning translates to roughly heavy alternator pulley dragging when the engine is hot. In other words, based on my experience, the "weight issue" is way overated, and is more an issue for my prototype than anyone else's fan by quite a bit. For my proto, the fan is just as hard to accelerate as the alternator... the billet ones being run now will take less power to accelerate than the alternator does.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: My New Fan!!
Posted by: CORSATURBO65 ()
Date: August 24, 2019 11:15AM

8/24/2019
HELLO KEVIN:

Thank you for the informative reply. I appreciate the update.

I would like to be counted as a "confirmed" buyer for one of your first production fans.

Please add mine to your back order list to help bolster support for your "sold" numbers, helping to justify your production run.

Send me a pm and an invoice as soon as the details are finalized and i will get you paid right away.

RICH FITZ
CORSATURBO65

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Re: My New Fan!!
Posted by: playerpage ()
Date: August 24, 2019 01:01PM

I don't deny that it's most likely somewhere in the nine pages above, but could you restate what the price tag is for production fan? I just might want to put myself on the waiting list as well.

____________________________________________

Eric C. Player, Porterville, CA
Member: CORSA National, Central Coast CORSA, South Coast CORSA, and San Joaquin Valley Corvair Club
THEN: 1965 Monza 110 Canary Yellow
1967 Monza 140 Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo; nicknamed "Bluvair"

"It would not have helped if I had [taken notes], as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

------

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Re: My New Fan!!
Posted by: joelsplace ()
Date: August 24, 2019 06:05PM

He hasn't determined the final manufacturing process so he can't have a price yet. I am also in the market for several but the quantity will depend on the price.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: My New Fan!!
Posted by: 63turbo ()
Date: August 25, 2019 08:43AM

CORSATURBO65 Wrote:
-------------------------------------------------------
> 8/24/2019
> HELLO KEVIN:
>
> Thank you for the informative reply. I appreciate the update.
>
> I would like to be counted as a "confirmed" buyer for one of your first production fans.
>
> Please add mine to your back order list to help bolster support for your "sold" numbers, helping to justify your production run.
>
> Send me a pm and an invoice as soon as the details are finalized and i will get you paid right away.
>
> RICH FITZ
> CORSATURBO65

Rich- As Joel said, I don't have a price for the production fans yet, although it is being worked on. Even if I did know, I cant take money yet, this part is at least a year away. There's lots of testing, and re-testing that needs to be done, both to establish the best set-ups for individual applications and to better document the performance of the fan, and compare with the stock one. Particularly of interest to me, and I'm sure many of you,
is this whole business of belt retention at high rpm and high acceleration loads... is it really only a fan inertia problem that causes the belt to come off? Because of experiments I've done and also knowing about the experiences of others, it might actually be the ridiculously high torque demands that the mag fan places on the belt from a way too high horsepower consumption, not "inertia". The steady state torque demand for the mag fan at 6k engine rpm is something like 15 ft-lbs, with the lower shrouds on. Only the lord knows at this point how much higher this is when the lower shrouds are taken off!!!
This same 15 ft-lbs+ number is also hit when the stock pulley ratio is used but the mag fan is cut down and the engine is taken to a higher rpm. I cant remember the exact numbers but the hp usage for a cut down fan but taken to rpms used by racers ends up being roughly the same as it is for the stock diameter. No one seems to have belt tossing issues under racing conditions when the hp usage for the fan is limited to around 10-12 hp, wether this is done by gearing down the stock fan or cutting it down plus reductions in pulley ratio to put it into that usage range, so it is a really interesting thing to test.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Current Page: 9 of 13


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