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Re: Bell Mouth #4!!!
Posted by: MattNall ()
Date: July 13, 2019 10:51PM

That's what it takes to find the "optimum"

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: Bell Mouth #4!!!
Posted by: joelsplace ()
Date: July 14, 2019 05:26AM

Amazing stuff. Can't wait for the final product.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Bell Mouth #4!!!
Posted by: Harry Moore ()
Date: July 14, 2019 11:00PM

Hi Kevin,

You are doing great work and I have been following your threads. I find it interesting the Volkswagen added this type of 'ring' to all fuel injected and emission controlled engines starting around 1973 to beetles....it is a stock part.

In the VW world this ring is called a "venturi" or "velocity" ring. I bought and installed a fuel injected shroud on the 71 Super Beetle.

I heard about desert testing GM did in 1967 with a Corvair that had AIR and CAC; even with the lower shrouds removed they couldn't keep the head temps down.

I believe if GM kept developing the Corvair, they would have added a ring like this.

Keep up the testing!!







This ring has been re-manufactured by Awesome Powdercoat and here is a video that describes how to install it:
Here is the add for the reproduction.

If you want I have a few links from The Samba that talk more about this ring.


Harry Moore
66 Monza Sedan 140/PG
Southern California



Edited 1 time(s). Last edit at 07/14/2019 11:02PM by Harry Moore.

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Re: Bell Mouth #4!!!
Posted by: 63turbo ()
Date: July 15, 2019 07:12PM

Thanks Harry! I learned something today, I didn't know about the venture rings... It makes sense though. Radius entry's, bell mouths venturi/velocity rings, whatever name is used are an important part for any good centrifugal pump/ fan system. They can add 15-20% to the efficiency for the system, and the enhanced efficiency shows up as more airflow at the same or less power usage. I would bet you that the extra airflow that VW got by installing that ring allowed the engineers to run the fuel injected engine's leaner at part load than they would have normally been able to do. I never would have thought that it was possible or safe to run my engine at stoich at freeway speeds without risking high head temps and/or rough running but sheesh! It does it and sure as heck seems to like it! 310 head temps going 70-75 with the air temperature at 70-75 and 3100 engine rpm, 14.5:1 air fuel ratio, smooth as silk!
As long as we are trading pic's, here's a pic of my guide vane bell (AKA the Tony D ring) painted up and installed

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

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: Bell Mouth #4!!!
Posted by: Harry Moore ()
Date: July 19, 2019 03:36PM

Kevin,

I am glad GM kept the flat mounting points on the fan shroud from the 1960 air cleaner/choke set-up. It allows for a nice mounting place for your ring.

It also allowed for a nice mounting place for the heavy duty pre cleaner option in 1965.


Harry Moore
66 Monza Sedan 140/PG
Southern California

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Re: Bell Mouth #4!!!
Posted by: 63turbo ()
Date: July 20, 2019 06:15AM

Yes those mounting points are sure helpful for my purposes, although on the later shrouds that have the fan pulley belt guide present some mounting challenges, as one of the three mounting points is used for the belt guide.
I want to try and make something that will clear that area and make the bell mounting cleaner easier and more robust... Something like a ring with notches in it that allows the bell to solidly mount over the top of that area, and makes it easy to center the bell. I also plan on developing a guide vane version of my bell that will work right for the stock fan... the vane angle that works best for that is different than for mine.

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

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: Bell Mouth #4!!!
Posted by: joelsplace ()
Date: July 20, 2019 09:01AM

Results of a guide vane bell for a stock fan will be very interesting.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Bell Mouth #4!!!
Posted by: 63turbo ()
Date: July 20, 2019 09:18PM

joelsplace Wrote:
-------------------------------------------------------
> Results of a guide vane bell for a stock fan will be very interesting.


You got that right! Supposedly, nearly all centrifugal devices have some tendency to spin somewhere in or near the inlet, some much worse than others,
even when they have a nice "throat" section like turbos have this same thing can happen. It might be that the lack of this throat and super short turn that
the tendency to spin is even worse with the stock fan. This is an easy thing to test if anyone is curious- with the engine good and warm, damper doors full open, take a strip of paper, place it near (PLEASE BE CAREFUL!!) the air intake, well away from the fan belt and alternator, and see where the strip is aimed, under the influence of the intake wind.... if the strip tries to follow the fan rotation, it is spinning! if it tries to go straight in, none or little spin is present.

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

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: Bell Mouth #4!!!
Posted by: Harry Moore ()
Date: March 10, 2020 06:48PM

Hi Kevin,

Now that your fan is flying off the shelf winking smiley
Any update on your ring? Especially for a stock fan?

Thanks


Harry Moore
66 Monza Sedan 140/PG
Southern California

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Re: Bell Mouth #4!!!
Posted by: 63turbo ()
Date: March 10, 2020 08:15PM

Hi Harry- at this time, I have not attempted a version for the stock fan yet. I do
know that the absolute best version for the stock fan would be like guide vane version #6, which has even bigger, more aggressive blades than any of the others that I've posted, except that the blades would be "straight up". #6 may well turn out to be the best one bar none, but it requires a bit more testing in ways that I'm not able to do, and so it has been sent to someone that will be able to push it better. I will tell you this... that bell is my favorite of all the ones I've tried, and would be too simple to make a "straight up"version that would be perfect for the stock fan. It has been an eye opener to me how much extra pressure
can be developed in the shroud with these guide vane bells, vs a standard bell and no bell. Spinning air in the intake is bad news, and the Corvair intake system apparently has a lot of it!!

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

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: Bell Mouth #4!!!
Posted by: ral1963 ()
Date: March 22, 2020 03:15PM

Kevin,

I have a performance engine in my 63 Sprint, it a 176cu, high compression, 140 based engine.

I am running dual CHT gages in my dash. I would be interested in doing some testing of your "Guide vane version #6" bell using my stock magnesium fan.


I could easily do a series of runs after the engine is at temp, recording the temps of both heads with and without the bell as a base for some starting numbers.

Rick Loving
Corvair historian & chronicler of useless facts
CORSA
Performance Corvair Group
Chicagoland Corvair Enthusiasts

RAL1963@COMCAST.NET
Just south of Chicago IL

Current Ride
63 Sprint Vert 140/4sp

Past Rides
60 700 Sedan 80hp PG
63 Monza Vert 102hp 4 spd
63 Monza Coupe 140hp 4 spd
63 700 Sedan 80hp 3 spd
64 Monza Vert 110hp 4 spd
64 Monza Coupe 95hp 3 spd
64 Monza Sedan 110hp PG
65 500 Coupe 95hp 4 spd
65 Monza Coupe 110hp PG
65 Corsa Coupe 140hp 4 spd
66 Turbo Coupe 180/4sp
68 Monza Vert 140hp 3 spd

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Re: Bell Mouth #4!!!
Posted by: 63turbo ()
Date: March 22, 2020 04:42PM

You know, That would make for a very interesting test, even though #6 is better suited to fan blades with a forward lean to them... they are close enough that it ought to make for a VERY noticeable difference in head temps, as it positively stops the spinning intake air, and this spinning seems to be a bug all by itself.

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

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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