Good Progressive Two Bbl?

[Titleist16]

The guy that's putting in my engine said that it would be a good idea to upgrade from my 1bbl to a progressive 2bbl. I am thinking about it but I am wondering if it would be worth the extra money. What are some good progressive 2bbl carbs? Anybody got a good running one lying around? By the way here's what I had done to the engine: 78 engine, 9.2cr Silvolite pistons, head milled, block decked, balanced, 264 FSPP cam, Pacemaker dual out headers, 3 angle valve job, V-8 springs, Comp cams high energy timing set, FSPP lifters, Corteco gasket set, FSPP chrome moly rings. Starting in September I will be going to school and it's a 100 miles round trip 5 days a week so I don't want a carb that's going to suck down gas. How much performance would I gain but how much gas mileage would I lose with a progressive 2bbl?

 

[Junk-Falcon]

with the

 

[WhitePony]

It's all a matter of flow. With a Holley-Webber 5200/ Webber 32/36 (Basically the same carb), your flow will be comperable to what you are getting with a 1bbl during normal conservative driving conditions. So I would imagine that you won't lose much or any at all if you get it tuned up. I've had folks tell me that they are getting anywhere from 24 to 26mpg with that setup, and still have a considerable amount of power when thay want it. With those headers and the cam your choke point is definately the carb.

I'm curreently building up my engine, and it sounds very similar to what you have done. I'm using a HW 5200 with a Clifford carb adapter on a 79 head from a Fairmont. From what I hear, the trick is getting the carb tuned. I guess the 5200 or 32/36 can be a real headach to tune. One small thing to consider: Mike at FSPP tells me to use the old exhaust manifold until I get mine tuned to keep from burning the JetHot coating on the Pacemakers if the carb gets too lean while I dial it in.

Kris

 

[Titleist16]

I forgot to mention that the 100 mile round trip is all freeway driving, that's why I thought that a 2bbl would use more gas.

 

[Titleist16]

what's the difference between a regular 2bbl and a progressive 2bbl? At what point does the second barrel open up on a progressive 2bbl?

 

[xctasy]

You cant go wrong with a 350 Holley or 5200 Holley Weber. How well it suceeds is up to the nut doing the tune-up.


The secondary barrel of any progressive 5200 Holley Weber comes in at 60% of wide open throttle. Then it opens sharpley, and is rich. At part throttle, it is a very economical carb, better than the 350 Holley 2-bbl .

In terms of flow, the 5200 primary barrel is restrictive, but can be made to run lean without damage. Under wide open throttle, it richens up, and is a little more restrictive thana 350 Holley.

The difficulty in tuning the Holley Weber 5200 is the simple 'name the parts and how they work'. It's not like a good old 2-bbl 350 cfm carb, its an advanced Italian carb, but it is certainly more economical when tuned.

In terms of power, the 5200 carb with stock (2000/2300 Pinto, 2600 Capri or 2800Pinto/Mustang) choke sizes has an easy 125 hp power potential on an engine with just headers and a good ignition sysyem. With more cam and better flowing D2 on wards heads, maybe 155 if the carb is fly cut open to 30 and 31 mm primary and secondary sizes.

In regards to power and economy if tuned properly for the application, the 350 and 5200 are similar. The 350 runs a little better with regards to emissions, and can work better right out of the box becasue its simpler to tune.


Info from 2000 cc Pinto tune ups in the 70's and 80's by APT's David Vizard confirms any two barrel is a good idea, and I've stollen the inforamtion for your benefit!.

 

[Mustangaroo]

Titleist16,
You won't lose any MPG in fact the Holley 5200 will get much better MPG than that old single barrel carb. Both my son and I have ran the holley 5200 on different engine builds mine stock his mild build nad we both picked up 5-10 mpg when driven normally Plus your car will perform better, you didn't list what auto you are installing this in, but most will reguire a adapter and new throttle cabling to make it all work. But as many here will tell you that the Holley 5200 is one of the best med HP carbs you can put on our sixes! Now when you decide to go just for power the Holley 350 on a log head has delivered great results in performance but from experiance I'll tell you the Holley 5200 will put a smile on your face and money in your wallet once installed!

 

[Titleist16]

Does anybody have a Holley 5200 sitting around in good condition that you want to sell? What places have the best prices for this carb?

 

[WhitePony]

Best place to get one is from Stovebolt. They charge $65 for a rebuilt HW 5200.

Holley-Webber 5200

 

[Anonymous]

$65 is CHEAP.
I see them on ebay selling for $30-$40 and needing to be rebuilt.

 

[Anonymous]

Hmm, Its time to start looking into this. Just installed the Mallory Unilite and now want to work on the carb then onto headers.