Need to examine Weber

356 Porsche-related discussions and questions.
Message
Author
User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Need to examine Weber

#1 Post by Ron LaDow »

Working on an improved air-filter adapter to fit Solex air filters to Weber carbs. I need to examine a Weber IDF to make sure the throttle return spring perch never makes that part a 'throttle hold open' spring.
I'm in SF, would gladly travel upper peninsula or pay for shipping both ways. and toss in a Pre Mat Emergency PU Tube for your trouble.
Anybody?
You can respond here or call 415-252-1428;
Ron LaDow
www.precisionmatters.biz

User avatar
C J Murray
356 Fan
Posts: 9143
Joined: Fri Oct 23, 2009 7:24 pm
Location: 30MI WEST OF PHILA
Contact:

Re: Need to examine Weber

#2 Post by C J Murray »

Hi Ron, the Webers use a watch spring wound around the throttle shaft so no Solex type spring, HOWEVER the Weber springs are weak and with all the Porsche linkage I always add Solex springs. Problem is that you need to attach something to the bottom of the air cleaner to take the top of the spring SO you could make all this any way that you want that looks good to your discerning eye.Not sure why the pic is sideways. Click it and it corrects. :shock:
Attachments
IMG_0184[1].JPG
'57 Speedster
'59 Sunroof
'60 Devin D Porsche Race Car
'63 Cabriolet "Norm"
'67 911 S Original Owner
'03 Ferrari 575M
'09 Smart Passion

User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Re: Need to examine Weber

#3 Post by Ron LaDow »

Cliff,
I'm building the upper spring perch into the adapter plate, since it looks like everyone agrees with you. My concern is to get the spring perch far enough 'aft' such that, at WOT, the coil part of the spring doesn't foul that bulge that Weber sticks on there as a throttle stop.
That photo helps. Let me do a sketch; if you can give me a dim (+/- 1/16 or so), that might do the trick.
Perch Dim194.jpg
Cliff,
I'm looking for the distance between the rear of the Weber top casting and the location of your spring perch, and I'm assuming your spring does not foul that bulge.
Ron LaDow
www.precisionmatters.biz

User avatar
Craig Richter
356 Fan
Posts: 1305
Joined: Thu Dec 15, 2011 9:01 pm
Location: San Miguel de Allende/Traunkirchen

Re: Need to examine Weber

#4 Post by Craig Richter »

Ron,
I've run Webers on a lot of vehicles, and have played with this return spring geometry too much to admit. I like ($.02 worth) drilling a hole in the throttle arm as a lower spring mount, and run the spring parallel to the actuating rod to an air cleaner top spring mount. Similar to how you guys are doing it, just rotated about 70*. I like the progressive/resistance throttle feel this way. Mocking-up all these variable angles might keep you happily busy for an evening or two, and I'm looking forward to hearing your report.
 

User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Re: Need to examine Weber

#5 Post by Ron LaDow »

Craig,
Never fiddled with Webers on a 356, but have dealt with throttle linkages and return springs on many applications.
Two very important issues need attention:
1) Make sure the linkage and/or return spring load NEVER goes 'over-center' or foul such that it will not return from WOT!
2) Make sure there is a maximum return spring load near idle, since that is the condition where the pressure delta is such as to try to keep the throttle open and thereby make the idle erratic.
Anyhow, I'm fairly satisfied with the spring perch location re: the geometry in 2D from the rear. I'm just trying to make sure there is no fouling of that damn hump Weber casts on the body and that there is minimal axial load. So I'd prefer to get one in hand and take some dims.
Turns out The Stable doesn't seem to have any in the stores, haven't checked EASY Jim yet, but what I thought would be 'make a couple calls' is more difficult than that.
Repeat: Free Emergency Push Rod Tube if I can borrow your Weber!
Ron LaDow
www.precisionmatters.biz

User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Re: Need to examine Weber

#6 Post by Ron LaDow »

Got one in hand. Thanks for the offers.
Ron LaDow
www.precisionmatters.biz

User avatar
C J Murray
356 Fan
Posts: 9143
Joined: Fri Oct 23, 2009 7:24 pm
Location: 30MI WEST OF PHILA
Contact:

Re: Need to examine Weber

#7 Post by C J Murray »

Ron, my top spring mount is about 7/8 to 1 inch out from the top of the carb but that makes the spring further out at the top than it is at the throttle shaft. Note that the left and right Weber have their throttle levers at different distances from the carb body.
'57 Speedster
'59 Sunroof
'60 Devin D Porsche Race Car
'63 Cabriolet "Norm"
'67 911 S Original Owner
'03 Ferrari 575M
'09 Smart Passion

User avatar
Dennis ODonnell
356 Fan
Posts: 777
Joined: Fri Nov 05, 2010 6:44 pm

Re: Need to examine Weber

#8 Post by Dennis ODonnell »

Ron, have you thought of a coaxial spring around the pushrod behind the fan shroud with a small bracket for compression at the baffle and a washer at the threaded end of the balljoint? Kind of like an old Ferrari.

User avatar
Greg Bryan
356 Fan
Posts: 3679
Joined: Sat Oct 04, 2008 1:05 pm
Location: San Pedro, CA 90732; Fallen Leaf, CA 96150
Contact:

Re: Need to examine Weber

#9 Post by Greg Bryan »

I moved this interesting topic to the main discussion to give it a little more visibility.
Ron - did you get a response on a loaner carb? I have one I could loan if not...
Greg Bryan

User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Re: Need to examine Weber

#10 Post by Ron LaDow »

Greg Bryan wrote:I moved this interesting topic to the main discussion to give it a little more visibility.
Ron - did you get a response on a loaner carb? I have one I could loan if not...
Greg.
Yes. The Stable found one lurking, and I was able to get the dims I needed. The new plates with have upper spring perches.
In a conversation, someone mentioned that Del Ortos have the same mounting bolt pattern but need clearance for the fuel line and something else which I did not note down. Comments?
Ron LaDow
www.precisionmatters.biz

User avatar
Greg Bryan
356 Fan
Posts: 3679
Joined: Sat Oct 04, 2008 1:05 pm
Location: San Pedro, CA 90732; Fallen Leaf, CA 96150
Contact:

Re: Need to examine Weber

#11 Post by Greg Bryan »

Well, it's your lucky day - I have a weber and a dellorto carb in front f me
Air cleaner bolt pattern is the same
Dellorto fuel boss sticks above the surface about 4 mm whereas the weber is below the mounting surface
Dellorto air cleaner mount stud outer screws into very top and weber is recessed down to the carb body
Attachments
image.jpg
Greg Bryan

User avatar
Greg Bryan
356 Fan
Posts: 3679
Joined: Sat Oct 04, 2008 1:05 pm
Location: San Pedro, CA 90732; Fallen Leaf, CA 96150
Contact:

Re: Need to examine Weber

#12 Post by Greg Bryan »

PS - the weber throttle bore opening is tapered at the top to 43mm and the del is straight at 40mm
I think you can see in the picture
Greg Bryan

User avatar
Ron LaDow
356 Fan
Posts: 8092
Joined: Wed Mar 26, 2008 11:45 am
Location: San Francisco

Re: Need to examine Weber

#13 Post by Ron LaDow »

Greg, if the jet stacks and air vents are in the same locations, I'm pretty sure they'll fit as-is.
Ron LaDow
www.precisionmatters.biz

User avatar
GregVandenbussche
356 Fan
Posts: 339
Joined: Wed May 29, 2013 5:36 pm
Location: San Francisco

Re: Need to examine Weber

#14 Post by GregVandenbussche »

Hi Ron,
Something to consider for the weber and dellortos: lots of them have the jet doctor kit from CB, which is made of elongated idle jet holder (breather tubes)
easy holes to drill unless you want to use these areas for screw bosses or else...

Image weber IDF
Image Dellorto DRLA
image courtesy of their respective owners
Bt5 Super - used to be fjord green, was painted brass, then brown... sadness

User avatar
Ashley Page
356 Fan
Posts: 841
Joined: Sun Mar 09, 2008 6:08 pm
Location: Davidson, NC
Contact:

Re: Need to examine Weber

#15 Post by Ashley Page »

I formed my filter housings from sheet aluminum and made a stainless steel tab for the return spring to rivet to the lower filter housing.
I welded the spring attachment to the throttle arm to get the geometry I was after.
The springs are stainless from McMaster.
Snaps the throttle back just right I think.

Now I would like to find a paper element to replace the K&N element.

Edit: some things you remember in the bathroom and sometimes the phenomenon occurs when someone else is going. Just took my hound out to poop and I automatically transitioned into thinking mode since it was dark and I had nothing to read. What I remembered about throttles and what is, I think, sorely needed for the webers is a correct set of throttle arms. Everything I have seen and bought is junk. It's been a couple of years since I last looked but there were zero good solutions then for webers on a 356.
Ron, I think that is a potentially good product. (put me down for a set)
Attachments
image.jpg
image.jpg

Post Reply