32/36 Weber on a 38/38 Manifold

[2002#3]

 

For my rebuild, I likely will start with a 32/36 Weber and see how life treats me.  Great, stay the same; want more, switch to a 38/38.  Great, stay the same; want more, switch to dual 40's.

From what I have found on FAQ, a 32/36 Weber does fine on a hogged-out/peanut, i.e., one modified to accept a 38/38 Weber.  Am I correct?

Thanks.

Larry  

Edited November 18, 2022 by 2002#3
Edited Text

[BarneyT]

Yes, and you can work from there…32/36 best all around driving, 38/38 better sound/high rpm driving, a little more fun…side drafts you will get a ticket.

Edited November 18, 2022 by BarneyT

[Dudeland]

44 minutes ago, 2002#3 said:

 

For my rebuild, I likely will start with a 32/36 Weber and see how life treats me.  Great, stay the same; want more, switch to a 38/38.  Great, stay the same; want more, switch to dual 40's.

From what I have found on FAQ, a 32/36 Weber does fine on a hogged-out/peanut, i.e., one modified to accept a 38/38 Weber.  Am I correct?

Thanks.

Larry  

32/36 progressive seems to be the call on these things.  The manifold is not the best design, the immediate left hand turn. 

 

You can get a bit that makes the 32/36 synchronous, 

 

38/38 nobody seems to be happy with unless you are wide open full time. 

 

Side drafts seem to be an art in upon themselves. 

 

 

 

 

 

[2002#3]

Yes, Barney and Dude, you ain't wrong. 

I have side drafts (OK, so what if they're 40PHH's) on my '70 and know that route is fun. 

I'd like to try three carb combos with the up-grade build:   10:1 CR, 292 cam, and 91-mm bore.  I realize that the 292 will poke the engine to ask for a little more air at higher rpms and higher speeds.  I probably will take the 32 > 38 > 40's route for my education, but who knows... 

Larry

Edited November 19, 2022 by 2002#3
Corrected Spelling

[TobyB]

I know I keep saying this-

 

at 10:1, you can use more cam.  In fact, a bit more cam will give you a LOWER static

compression ratio.  Dynamic ratio will then build with revs, and the engine will breathe pretty freely.

 

As to carb- you can start with a well- mannered 32/36 for break in, but you'll get bored quickly.

So don't spend any money on one.

And yes, the manifold can be opened to 38 right from the start.  The peanut's even better, as it biases

flow a bit less.

 

I guess I've lived with all of them enough to go straight for EFI...

 

heh

 

t

 

[Mike Self]

When I first fitted a 32/36 Weber (around 1979) in place of the factory Solex, I had to open out the manifold at the carb mounting point by several mm to make the opening match the carb throats, and there was a noticeable difference between the Weber gasket and the manifold opening. 

 

Stuffed an oil-soaked rag down the manifold and had at it with a Dremel tool fitted with a steel burr.  When finished I carefully lifted out the rag, swabbed the manifold again with an oily rag and bolted on the new carb.  

 

mike

[jimk]

11 hours ago, TobyB said:

I guess I've lived with all of them enough to go straight for EFI...

 

I reached that conclusion in 2004 bought a TBI setup from Top End never looked back.

[Dudeland]

21 hours ago, TobyB said:

" In fact, a bit more cam will give you a LOWER static

compression ratio.  Dynamic ratio will then build with revs, and the engine will breathe pretty freely."

t

 

Dude where did you learn all this?  

['76mintgrün'02]

I did like Mike and port matched the original intake to the bottom of my 32-36.  I made a gasket to replace the oval-holed one in the kit, so its ports match as well.  (Back when I did that, I asked the forum whether I should peanut-ize the intake and the consensus was "no").  ((Right, Jim?))

 

I'm still using the carb that came with my car ten years ago.  New bearings in place of worn bushings and the seedy jetting prescription (plus one larger air corrector).  The needle on the AFR gauge says it's close enough. 

 

Bringing the secondary barrel in sooner makes a smoother transition on my car.  It feels a teeny bit peppier too.  If you like a touchy pedal, the 38 might be the carb for you.

 

I want a 36-32 Weber, because ninety-whatever percent of my driving is done on the primary circuit.  I wish it was the bigger of the two.  At least I think I do.

 

I don't find the carb boring on my high-mileage low-compression engine, but it'd seem silly to waste additional power if the rest of the engine had more to offer. 

 

I think the snorkelized stock air cleaner is a very worthwhile addition to a downdraft weber.  Especially if you can maintain the domed base with the smoooth rounded-over outlet into the carb.

 

I think a lot of being satisfied with what you have is not knowing what you're missing.  My winter daily driver (salt car) is a Soobaru with seventy-two horsepower.  

 

Tom

 

Edited November 20, 2022 by '76mintgrün'02
((Right, Jim?))

[halboyles]

I agree with most folks that the 32/36 is the best choice for everyday average driving.  The 38/38 offers a little more kick in the pants but not much. And, if you've ever used side drafts of any flavor, both the downdrafts seem flaccid.  

Since you are considering a progressive movement from one downdraft to another, I might have something of interest.  We are about to announce the availability of our new downdraft linkage system for the Weber 32/36 and 38/38. That's right, it works for both the popular Weber downdrafts with no modifications.  Here are some pics of the system.

[TobyB]

16 hours ago, Dudeland said:

Dude where did you learn all this?  

the internet.*

 

t

*and some of those paper things.  What were they called?  

Edited November 20, 2022 by TobyB

[John76]

14 hours ago, '76mintgrün'02 said:

I asked the forum whether I should peanut-ize the intake and the consensus was "no"). 

Good advice from the "peanut gallery".

 

14 hours ago, '76mintgrün'02 said:

I think a lot of being satisfied with what you have is not knowing what you're missing. 

Good advice from the "mintgrun gallery".  👍

[2002#3]

Thanks for the valuable aforementioned comments.  What I needed.

 

What is the difference(s) between the two ways two-hole manifolds can be bored out to accommodate 2-barrel carbs (discussed above), i.e., standard bore and peanut bore?

• the outer or general shape of the new larger opening? 
• the shape of the sidewalls of the opening? 
• the slope of the sidewalls?  straight down?  flared down and out?
• something else?

Thanks.

 

Larry

['76mintgrün'02]

Here are a couple of photos from when I did mine, ten years ago.  The previous owner did the hack job in the top photo and that is the gasket that comes in the kit.  I used a sharpie to trace the gasket to show where to remove material and made the two hole gasket to replace the oval-holed one.  The holes on mine do taper a little, I think, before they dump into the plenum.  

http://i1082.photobucket.com/albums/j375/TomBrock/Weber%2023%2026%20base%20gasket/031.jpg

http://i1082.photobucket.com/albums/j375/TomBrock/Weber%2023%2026%20base%20gasket/186.jpg

 

Here are two answers I got when asking about one hole or two under the carb.

 

Simeon said--

 

"Conventional wisdom is don't peanut just taper/ enlarge the holes to match the throats of the carb. Peanut-ting may slow the speed of the charge too much by increasing the plenum volume below the carb.

I am running mine on the stock manifold, untouched. This is just a phase I am going to grow out of on the way to sidedrafts so I haven't bothered. Too many people say that you can't feel the difference, even if the flow bench tell you it's good. Just drive it and rev it 250 revs higher before you change each gear."

 

To which Jim responded--

 

"+1

Finally there is a guy that understands what a sudden enlargement in an air stream does. It also causes fuel to recondense.

Flow bench testing a manifold alone does not tell the whole story. The flow bench test should be done with the carb installed both before and after peanutizing. And if the test apparatus is good enough, the after peanutizing results will be worse because of the sudden enlargement effect on the flow dynamics (it's another fitting loss coefficient in the air stream.)."

 

Tom

 

EDIT-- haha the bad old photobucket days.  click the links and small versions of the photos do show up.

Edited November 20, 2022 by '76mintgrün'02

[marlin1881]

Well, I'm going to be going through this discussion in detail, as I'm headed to take my carb off this afternoon.

 

I've got this old '76 2002, and so far:

- radiator rebuild with a local shop

- new alternator

- new starter

- water pump

- new fuel pump (mechanical)

- new battery

- Redline carb kit

- tires

- all new fluids

 

Need to do:

- heater hoses

- brakes, master cylinder, clutch cylinder

 

Carb (Weber 32/36) carb problems...

- Car will run ONLY if the choke plates are mostly closed

- If I open the plates, the car stalls.  If I close them, the car stalls

- Car came with a K&N filter on top.  I'm not sure this is a good thing, long term.

 

I'll report back as to what jets are installed when I break it down in a hour or so.

 

This is a great forum.  Thanks, guys.