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joemama Samba Member
Joined: February 09, 2006 Posts: 1635 Location: La Crescenta, California
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Posted: Fri Jan 10, 2020 9:51 am Post subject: bigger venturi for 34 pict 3 |
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Wondering if anyone sell one? |
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andk5591 Samba Member
Joined: August 29, 2005 Posts: 16754 Location: State College, PA
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Posted: Fri Jan 10, 2020 10:35 am Post subject: Re: bigger venturi for 34 pict 3 |
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Check with John at aircooled.net. I think he was doing something with those _________________ D-Dubya Manx clone - 63 Short pan,1914.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Cindy's daily driver.
Max - 73 standard Beetle hearse project - For sale
66 bug project - Real patina & Suby conversion
There's more, but not keeping them... |
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rayjay Samba Member
Joined: March 26, 2008 Posts: 1501 Location: Buford GA
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Brian Samba Moderator
Joined: May 28, 2012 Posts: 8340 Location: Oceanside
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Posted: Fri Jan 10, 2020 3:13 pm Post subject: Re: bigger venturi for 34 pict 3 |
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34pict3 vent is not a removable item, you'd have to ream it out. I had this done by Tim at Volkzbitz _________________ Wash your hands
'69 Bug
'68 Baja Truck
'71 Bug
'68 Camper
Only losers litter |
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joemama Samba Member
Joined: February 09, 2006 Posts: 1635 Location: La Crescenta, California
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Posted: Fri Jan 10, 2020 4:49 pm Post subject: Re: bigger venturi for 34 pict 3 |
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Brian. Were you happy with the results? I am thinking of doing it for a mild 1776 with Engle 100, running stock muffler and vaccum advance distributor.
Thanks. |
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Brian Samba Moderator
Joined: May 28, 2012 Posts: 8340 Location: Oceanside
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Posted: Fri Jan 10, 2020 5:20 pm Post subject: Re: bigger venturi for 34 pict 3 |
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It was on a 2007cc single port, it was pretty cool. Wouldn't do it again unless I had my own dyno and days to spend tuning it properly, doing more head work, more tuning and etc. _________________ Wash your hands
'69 Bug
'68 Baja Truck
'71 Bug
'68 Camper
Only losers litter |
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51057 Location: Surrey B.C. Canada, but thinking of Ukraine
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ccowx Samba Member
Joined: May 15, 2015 Posts: 654 Location: Whitehorse Yukon
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Posted: Sun Jan 12, 2020 12:57 am Post subject: Re: bigger venturi for 34 pict 3 |
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I will be curious to see how this works. I have a very similar engine and carb, but have not been able to fire it up. Mine is an 1835 with an Engle 100 cam, header(with pre-heat), '205AN distributor (recurved) and a 34-3 I have reamed out myself. It actually was not hard to do, it just took a couple of hours of careful work with a dremel tool. If you take out the plug and the butterfly/shaft, it is fairly easy. My venturi is 28mm and I am hopeful that I have the radius' not too far off!
I tried to remove the venturi, but even with the plug out it did not want to come out for me.
Chris |
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FreeBug Samba Member
Joined: March 12, 2012 Posts: 4278 Location: deepest, darkest Switzerland
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Posted: Sun Jan 12, 2020 1:29 am Post subject: Re: bigger venturi for 34 pict 3 |
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This. Harder to remove than on a PDSIT, but removable nonetheless |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7182 Location: Videbaek Denmark
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Posted: Sun Jan 12, 2020 5:32 am Post subject: Re: bigger venturi for 34 pict 3 |
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Hello.
When the plug and shaft is out it is easy to remove the venturi. Occasionally it is beneficial to het the body a little to loosen it, but normally a gentle tap with a big screwdriver will send it on its way.
I will not say that it is impossible to ream the venturi out with a Dremel, but thge risk is that you move the break point too much. If that happens the signal to the aux venturi gets significantly changed and you can end up with a carb that is difficult to jet.
28-28,5 mm venturi generally works well on engines in the 70 - 85 hp region. Also, with that size the vacum signal is still "trustworthy" At even 29 mm venturi it begins to alter the vacum signal. (It should not have anything to do with each other since the vacum is basically run with/on the idle circuit, but it does.)
29/30 mm venturi is only interesting at at least 1835 cc and 90-110 hp.
2 l plus engines can be run with no venturi, but the jetting becomes rather funky. Also, if you want it to work well you should really use a programmable ignition such as the CB Black box. With this you can iron some of the issues out and make it work well. - It can be done with a regular 009, but it is very difficult. With a programmable it is so much easier.
As a rule of thumb sgl port engines want a 10% smaller square venturi for the same displacement. If you keep the factory steel intake there is no idea in going larger than 28 mm (on a street engine) because the manifold will not be able to flow more. In fact the difference between a 26 and a 28 mm venturi is minor. Converting to a better manifold and everything changes. |
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joemama Samba Member
Joined: February 09, 2006 Posts: 1635 Location: La Crescenta, California
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Posted: Mon Jan 13, 2020 12:24 am Post subject: Re: bigger venturi for 34 pict 3 |
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Here is my carburetor
removed spring
removed screws
you have to use a screwdriver that fits well, the screws are tough to remove because they are peened over to keep from backing out
butterfly removed
removed linkage from throttle shaft
removed electric idle solenoid
pulled throttle shaft out
you can see the venturi, as well as the plug that keeps it in
drilled a small hole thru the plug and used a slide hammer to pull the plug free. I can reuse the plug with some jb weld to plug the hole I drilled and to hold the plug in
removed the top of the carburetor, you can see the venturi
used a wood dowell and hammer, tapped different spots around the venturi, and drove it out
looking at the venturi, looks like I need to find someone with a lathe, and enlarge this area by 2mm (is that correct, Allstrup?)
Also, here is the manifold I plan to use, its from a '71, I cleared the heat risers with a drill motor and a wire cable
measuring across the intake it is 1" 4/10, which is about 36mm. Im hoping that is large enough to handle the 28mm venturi
If I can get verification that this is the area I need to enlarge, and doing just that is what I need to do, I will proceed.
Thanks.
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7182 Location: Videbaek Denmark
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Posted: Mon Jan 13, 2020 4:09 am Post subject: Re: bigger venturi for 34 pict 3 |
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Yes, but the best way is to continue the taper to the bottom or at least close to.
There is no need to drill the plug. Just take a big screwdriver and give it a couple of punches from the inside and it will come out. |
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Rome Samba Member
Joined: June 02, 2004 Posts: 9602 Location: Pearl River, NY
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Posted: Mon Jan 13, 2020 4:52 am Post subject: Re: bigger venturi for 34 pict 3 |
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Thanks for the detailed procedure, joemama. |
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gt1953 Samba Member
Joined: May 08, 2002 Posts: 13843 Location: White Mountains Arizona
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Posted: Mon Jan 13, 2020 6:55 am Post subject: Re: bigger venturi for 34 pict 3 |
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I have always wondered why Solex did not make a larger single center mount carb. Like say a 38 Pict. _________________ Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.
72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold}) |
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rayjay Samba Member
Joined: March 26, 2008 Posts: 1501 Location: Buford GA
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Posted: Mon Jan 13, 2020 7:11 am Post subject: Re: bigger venturi for 34 pict 3 |
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gt1953 wrote: |
I have always wondered why Solex did not make a larger single center mount carb. Like say a 38 Pict. |
VW was probably the leader of the pack when it came to FI on production cars so would have no need to spend money on further carb development. |
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joemama Samba Member
Joined: February 09, 2006 Posts: 1635 Location: La Crescenta, California
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Posted: Mon Jan 13, 2020 8:07 am Post subject: Re: bigger venturi for 34 pict 3 |
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a few years back there was a kit on the market for a single Kadron. I always thought that would have worked well. |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7182 Location: Videbaek Denmark
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Posted: Mon Jan 13, 2020 11:32 am Post subject: Re: bigger venturi for 34 pict 3 |
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joemama wrote: |
a few years back there was a kit on the market for a single Kadron. I always thought that would have worked well. |
It does, and it donīt.
In warm and dry climates like Southern CA,Arizona, NM, Texas and similar it works quite well. In slighty more chilly climates like here for instance, the warm up period is just downright impossible. Makes the engine jerk and buck until some heat comes into the manifold. Next it was soon found out that it was not the carb that was the problem, its the manifold and end pieces. A 34 mmn Solex Pict3 or 4, can supply 100 hp (street) with no other mods than the venturi change and a rejet, and a proper aircleaner. (Going extreme it will handle up to about 120 hp.)
A modified 34 Solex with a 37 mm butterfly and a custum venturi along with a modified CB/Empi center section and modified end castings (or a set of Wensings new larger I.D. castings) will support 120 hp and up to about 130 in the extreme.
With this solution "everything still fits" and you do not need to fight with a flimsy linkage and what not as with the Kadron conversion. Thatīs why I for one abandonned the centermount Kadron solution |
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joemama Samba Member
Joined: February 09, 2006 Posts: 1635 Location: La Crescenta, California
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Posted: Mon Jan 13, 2020 1:51 pm Post subject: Re: bigger venturi for 34 pict 3 |
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Alstrup, sorry if I am being dense, but I want to be sure
Are you saying That I need to open up both these areas, the "belt" at the narrow part of the venturi, and also the slightly beveled area from there down to the end of the venturi?
Thanks. |
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rayjay Samba Member
Joined: March 26, 2008 Posts: 1501 Location: Buford GA
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Posted: Mon Jan 13, 2020 3:44 pm Post subject: Re: bigger venturi for 34 pict 3 |
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Imagine that the inside of the venturi is the top surface of an airplane wing. An airfoil in other words. You want a smooth radius so that the air stays attached. So really you want to blend both the top transition to the new larger bore and the bottom. Really, there should be no parallel portion of the venturi. |
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joemama Samba Member
Joined: February 09, 2006 Posts: 1635 Location: La Crescenta, California
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Posted: Mon Jan 13, 2020 4:18 pm Post subject: Re: bigger venturi for 34 pict 3 |
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Currently the part where the pen is pointing to, is practically a flat belt, with a sharply defined top and bottom edge. So sounds like along with widening the hole to 28mm, those sharp edges should be smoothed out and blended in.
Thanks. |
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