Weber 32/36 & H/W 5200

[Anonymous]

I've read through some of the old posts that say the difference b/w the two is the 26/27 venturi size of the 5200 vs the larger 32/36. Well, I've also been reading the specs. for the Weber 32/36 off of multiple vendors' websites. They state that the 32/36 also has a 26/27 venturi size.

So, I'm curious now. If the venturi sizes are the same in both carbs, what is the real difference between the two? Just flow ratings?

 

[xctasy]

That's right, just flow ratings, oh, and any selective machining and casting changes made over the years. Bressel, Pierburg, Weber and Holley all had a go, and called it the 32/36 DGA (V?), #5200 Holley, and there were various other incarnations as well.

There are three ratings I've seen.
*198 CFM @ 1.5" hg (David Vizard, 1975 test),
*230 cfm at 2" Hg (Holley/Weber carb list),
*280 cfm at 3" Hg (Holley Carb list).

A forth is stated as 320 cfm, but I really doubt that figure.

In the Holley lists, they used imperial measures for the carb venturis of 1.025 and 1.0625".

Then there were Chevy Vega and Chrysler 2.2 versions of the basic carb, called 5210 and 6200, which were rated at 255 and 280 cfm, methinks.

Incidently, there is space in the casting to ream the primaries/secondary venturis out to 30 and 31 mm, respectively. This takes the carb flow up to 20% higher if you remove the cold start choke. 336 cfm at 3.0" Hg. Enough to flow 150 hp or so, well up from the 125 hp you can reasonably expect form a Holley/Weber.

The 38 DGA(S?) is a simultanoues carb which is a better bet. I understand Clifford have them in stock.

 

[Anonymous]

So where does the "32/36" come from? : Is it just a name that Weber picked for it?

 

[xctasy]

Thats the throttle sizes, 32/36, or 1.25/1.425 in Holley/Weber speak. These carbs a have very small venturis, which makes them work very nicely. Most carbs have no more than 23% restrictions when you divide the throttle diameter by the venturi diameter. On the 32/36, the primary is 23%, and the secondary is 33%. Any time you have a big restriction like this, the carb can create a very strong signal, and this helps fuel efficency, often at the expense of maximum power.

The power mod I've seen goes right up in venturi size by a bore out of 160 thou, taking the carb out to flow more through the venturi. It looses signal since the difference in throttle to venturi ratio is like 7 and 16%, respectively. So power and flow goes up, and the engine tends to bog more and have a less well atomised mixture.

Weber sure did there homework when they made this carb. It came out in 1969, and 34 years on it's still a top piece!

 

[Anonymous]

So does the Holley 5200 have the same throttle size (32/36) as the Weber? From the pics. I've seen of the bottom of both carbs, they look the same.

 

[xctasy]

Yep, the very same. The #5200 is just the same carb as the Italian Weber 32/36, made in the US of A.

 

[hotrodbob]

Great info. i just bought one of these carbs from Stovebolt. I plan on putting it on a 200 that has a 250 head with unshrouded valves and blended bowls along with .040 milled off, a 262 Isky cam,.030 over bore and header. Will this carb be large enough? I also have an adapter to run a Autolite/Motocraft/Holley 2 bbl. What do ya think I should run?

 

[xctasy]

You got to sit down and figure how much fuel economy you want to loose. Ford undercarb all sixes because they think economy rules. They didn't do 2-bbls in the States because they didn't have space for them on 250's and didn't want to show up there 289 and 302's.

If you run a 350 Holley, you'll be very happy. It's my pick, as long as you don't want to use it for Auto-X, where can get fuel starvation in tight turns.

If you run the 32/36 or #5200 you'll get very good economy, what most people thirst for! The HolleyWeber is unaffected by fuel slosh, it can be mounted in any positon. Capri V6's had 'em turned around 180 form the stock position with no problems.

Only thing is you're engine is limited to about 125 hp with this, while the Holley 350 could take you up another 10 hp with a little loss in fuel economy.

Either one is a good step. You can't make the wrong descison, only one of two better ones!

 

[Anonymous]

why couldn`t you run two 5200 s ?

 

[hotrodbob]

Thanks for the clarification. I have the adapter for the larger 2 bbl and the 5200. Since my kid will drive the Falcon I'll restrick his HP with the 5200, but my 250 will get the 350 holley.

As far as 2 5200's, that's not a bad idea. I'll have to weld up a mount to the log, but that is an idea to ponder.

 

[FastRonald]

8) Wow..........I like that idea as well. A pair of 5200's is worth trying on a spare head or at least a trial set up.