HW 5200 Carb- Modifying Ventruis for the 250 ci Six

MercuryMarc

MercuryMarc

Well-known member
My HW 5200 2B runs OK - about the same as my 1940 Holley 1B so I am very dissapointed. It gets the same mpg as my 1940 and it really bogs at mid range. I got this one off eBay and rebuilt it myself...
So since I have the linkage, air cleaner, and adapter all set up, I'd like to try a 2B (HW 5200 or Weber 32/36) that was rebuilt by a pro (or someone other than me...).
On eBay the remanufactured ones go for over $100.
The new ones are over $300.
Yet the one at Langdon's Stovebolt are $65.
http://www.stoveboltengineco.com/acartpro/product.asp?productid=149
This seems to good to be true so I am naturally skeptical.
Has anyone purchased one from Langdon's Stovebolt and had success?
Thanks-
Marc
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it could all be related to jet size. what are you running?

Stang200 gavce me list of what he found thru trial and error as the proper jets sizs...let me see if I can dig it up
chaz
 
Prim Hi Speed Air 180
Sec Hi Speed Air 150
Prim Main 132
Sec Main 135
Pump Jet 80
Prim Idle 60
Sec Idle 80

Adjusted the carb to work best at
Idle Speed Screw 2 1/4 turns out
Idle Mixture Screw 1 3/4 turns out

Idles great, converted to electric choke and starts great cold
Very slow at the top end
Bogs at midrange
Gas milage no better than my 1940 Holley 1B

Thanks!
 
Howdy Marc:

Another variable you should be aware of is that the Holley/Webers on US cars range in CFM capacity from 235 to 270. If you H/W is one of the smaller capacity type, 23 mm primary and 27 mm secondary, you will not get much of a performance increase. The size of the venturi is cast onto the side of each barrel.

Tuning is critical to getting the most out of these little gems. Make sure your initial timing and distributor advance is optimized too.

Adios, David
 
Is there a good source of tuning info on these carbs, like what to change first, etc? Just curious...
 
Your jets are very close to what mine were in the 5200 I bought from Tom at Stoveboldt:

Primary main: 132
Secondary main: 135
Primary air corrector: 180
Secondary air corrector: 195
Primary idle: 10
Secondary idle: 80

He indicated that the 10 was probably a mis-stamp, which apparently was common. His advice is to double check the float level and the fuel flow, both of which were fine on mine.

I swapped the two air connectors and installed 160 mains: lots of bog still. I've just replaced my 160 main with a 157 main and it seems to be much less pronounced. I may switch my accelerator pump nozzle to a double-pumper to see if that helps. I'll let you know.

Try your mains. They seem too small, even given your moderate mods. I'd work closer to the 155 range. Try http://www.holleypartsforsale.com/index.php
for pretty reasonable jets (mains only).

best,
--tom
 
MercuryMarc, thanks for the info, lotsa good reading there at Redline.

Speaking of which, anybody have any experience with their 1-bbl to 2-bbl adapters? They look to be shorter than the Clifford ones, and might be a better way to go...?
http://www.redlineweber.com/images/kits ... it%20a.jpg

EDIT: Whoops, never mind, they look just like the Stovebolt adapters.
 
The 26 and 27 mm venturis are common to all 15 of the Holley Weber carbs in the Holley catalogue. Problem is there are actually 5200's which flow 230 cfm (#7343) and 5210 series ones which flow 255 cfm (#7344) and 6520 series Holley Webers (#9655) which flow 280 cfm. They all have similar sized main throttles but lots of little differences. They are all 32/36 Weber Work-alikes, but they have only changes to the placement of components, like the air horn, the choke and the position of the secondary and primary barrels, and the arrangement of the fuel bowl.

They are designed for only for 1.6 and 2.0 liter four cylinder engines, nothing more than that. They are limited to about 125 hp in stock condition when prefectly tuned. They got put on US Maket Capri 2.6 and Capri/Mustang 2.8 engines only because Ford America needed a good, economical carb.

In no stock instillation does it ever get more than 102 hp net, or 112 hp gross. The 2.6 and 2.8 were only 100 hp engines.

The venturi size for the 3.3 is just fine at 26 and 27 mm.

But adding another 25%, or 50 cubes, makes the engine very restricted. The reason you are not getting the economy and performance is becasue the carb is too restrictive. Jetting the air correctors and jets is the only help you'll get, but don't expect it to exceed the performance of the bigger 1-bbl carbs unless you get into the carb itself. Resign yourself to basic jetting changes, and have it set up on a rolliing road/dyno.

Cfm for all 5200's excpet the #7343 is 280 cfm at 3" Hg. Actual flow at 1.84" Hg is about 230 cfm, and its easily confused with the other 6520 and 5210 carbs.

Over in Australia, anyone running a 250 has to up size the stock 32/36 Weber carb the 5200 is based on to venturis which are 30 and 31 mm. You do this by having a machinist fly cut the venturis with the boosters removed, and then you emery paper the venturi back, reclean and reassemble the carb, and then use slightly bigger jets.


Or run the much better 38 DGEV carb, which has 29 mm venturis.

Stock Fiat 131/124/132 based Weber ADM 34's on aour 3.3 and 4.1 Falcons have two 30 mm venturis, and work just fine at that size.
 
er....i got lost in that

can you pinot us to a link of what you reccomend we buy....I work better with pix and stuff

:)
 
The American made 5200 Holley Weber
Pintocarb.jpg


is a mirror image of the imported Italian or Spanish built 32/36 Weber
vacuum.jpg


No matter what place its from, it has a 26 and 27 mm venturi, and flows 280 cfm at 3" Hg unless its one of the odd ball Mercury Fiesta 1600 carbs.

The trick is to jet it right to the Stovebolt or Clifford specs, and then realise that it is going to need a little more internal machine work to go well on a 250 vehicle.

It'll work on a 250, and be economical and perform okay, just don't expect it to out do a 1-bbl Carter or Holley on the 250, because those carbs were really big. The 5200 or 32.36 is a brilliant small economy carb which needs the venturi modification I mentioned to give power above 3000 rpm on a 250 engine.

Everything I know about the venturi mods, I know becasue some else has taught me. Here are my sources!
it is described in David Vizards Modifiying Fords OHC engines (Ford Cortina, Pinto, Capri, Sierra, Euro Granada), a 1984 book. Read Chapter 4, Air filters, carburetion & manifolds. 22 year old wine!

b-41.jpg


see http://www.aptfast.com/APT_Parts/Books/ ... 1_info.htm

The mods allow a small 5200 carb flow 338 cfm, just shy of the 350 cfm 2300 series Holley. Those carbs can go to 125 hp with the right air cleaner and stuff, and probably about 170 hp with the venturi and carb air horn mods desribed.

Another thing. The 5200 and 32/36 carb has California Air Resources Board approval on other foreign cars as a sanctioned modification (280 Mercs, BMW 2002's, Opels GT's and 1900 Ascona's). Since its a great carb, why don't we get an EO order to fit one to our Ford sixes, rather than have people tell us we can't just slap a Holley on our Fords. Others can slap Euro Webers on there cars, why can't we put a 5200 Holley on our car?
 
Thanks everyone for all the info!
I have a lot of thinkin' to do about whether or not I am really going to mess with the 5200 after all on my 250.
 
Ok- so it's been 7 months and 3 carbs later...
(2nd HW 5200, then 2 manual choke Holley 1940's) and I' ready to seriously modify one of my 5200's- so I'm planniing on carefully enlarging the venturis to increase the diameter 2 mm on each. Tonight I measured the minimum ventruri diameter (a bit tough with the nozzle spanning the middle) and get 27 and 28 mm which I think confirms that they are really 26 and 27 mm. I'm plannng on tackling this myself- suggestions welcome!

Can I "machine" my carb at home with a file/drill/dremel/sandpaper?

I'm not too worried about destroying the carb since it was and "eBay special" and currently just occupies space in my garage....

Thanks!

Marc
 
This may be good news for you A heavy hand and basic tools might work better for you!

David Vizard felt any major 'botch ups' where you over excavate metal in the venturi was easily fixed with JB Weld (Devcon) and linish it back with emery paper. In practice, your reprofiling the venturi by less than 60 thou each side, so its not that hard to do with Devcon .


The technically better method is to use the right tools, but practical machine shop skills are slowly dying out.


I've personally not tried anything but flycutting alloy when making carb bodies for my LPG systems. Pretty much the same deal as upsizing the carb venturi.

The bodies of the 5200 are made of Zinc Oxide or some kind of aluminum alloy. So you will have a hard job using dremel unless you can organise a cutting stone which doesn't get clogged all the time, and is the right size.

Alloy cloggs any stone, and going from 27 to 31 mm accurately in metal will need a dilligent work with a die grinder with high speed steel cutting tool at the very least. Then take tiny cuts at it, and finish hone with a spherical linishing stone. Which will always clogg up, and need plenty of kerosene, parrafin, CRC or WD-40
 
Got a drill press? You could wrap a cutoff broomstick or PVC conduit in tape to "bush" at the start size, put it in the drill chuck and use to centre the carb bore. While still engaged, clamp down the carb.

Remove the broomstick piece from the chuck and fit a 1¼" holesaw. Run it through slowly with a gentle squirt of lighter fluid or kerosene. Use magic marker to colour in the recut section, as a guide to blending the new venturi size to your previous bore walls.
 
Great suggestions!
I have taken some sandpaper, my drill, some tape, and some PVC pipe and already enlarged the 27 mm ventrui to 29- very easy to do-
will post pics later!
Now back to the garage!

Thanks!
 
I'd be coruious to hear how it worked out. When I went fromt the 32/36 to the 38 (with the 29 mm venturis) I noticed a significant difference in the upper RPM range.
 
Cris-
Seems to run really strong when the secondary opens up!
No more midrange bog either.
I think the 26/27 venturi size was too small when revving high- choking the engine.

I found this calculator-
http://www.carburetion.com/calc.asp

Seems that if I am at 6000 RPM then I'd need 368 CFM even for my non-modified 250- I think that was way more then the 5200 could deliver.

I am not surprised that you and I both experienced a performance increase with higher flow carb set ups.
 
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