Follow up on Holley 5200 or Weber 32/36 on 250 engines

[66 E100 Pickup]

A number of you have indicated that you were going to try these carbs on your 250. What have you found out?

I am thinking about using one of these on my BB6 240. I have to stay with the stock intake because of space limitations in my older econoline. The BB6 guys typically slap on a cliffy or offy intake with 2 or 4 barrel carbs. I am trying to get what I can in the same fashion as your SB6 engines.

John

 

[250mav]

im using a 5200 fine on my 250 with a adapter plate, its not direct mount. i cant say it'll be the same on a BB though. you can probably get away with more CFM's on a 240-300

 

[66 E100 Pickup]

well, that's encouraging. The 5200 is supposed to flow 280 cfm at 3" hg, so I am pretty sure that the 32/36 Weber (which flows 320cfm) should be just fine.

Other BB6 guys are running Autolite 2100s with 1.14, which was stock 289 Mustang in some years. These flowed about 300 cfm.

I would go Autolite (for a good upgrade at low cost) but it has a big footprint (3 1/2" x 5") vs the 5200 and 32/36. I can't overhang the stock intake more than about 1 1/2" or I am in the doghouse (literally).

Since I am trying to shove it all into a 1 3/4" manifold hole, the progressive carbs may be just fine, and should be much better than my 210 cfm 1101.

John

 

[xctasy]

Some of the CFM figures you have are wrong, and have been wrong on a lot of other publications.

Holley baselines all its 1 and 2-bbl carbs at 3"Hg, but no-one else adhears to there logic.

The 5200 is indeed a 280 cfm carb at 3"Hg, but so is any Weber 32/36. The figures for the Chevy Vega 5210, and Chrysler K-car 6200 were about 255 cfm.

The 320 cfm relates to the 38 DGAS.

Flow bench figures for 1 and 2-bbls should be 3"Hg test pressure, but no-one tests to that pressure. Both 5200 and 32/36 flow 227 cfm at 1.85"Hg.

No matter, just be aware that the stock 1-bbl carbs are pretty good, and that any 32/36 or 5200 carb is actaully quite small, and may not work really well right out of the box. If its modified with larger venturis, and some simple work on the air horn, you can get up to 336 cfm at 3"Hg out of a 5200 or 32/36

 

[66 E100 Pickup]

If its modified with larger venturis, and some simple work on the air horn, you can get up to 336 cfm at 3"Hg out of a 5200 or 32/36

Ok, so a 5200 is not always a 5200 is not always a 32/26 Got it!.

Where can I get info on modifying the venturis/air horn?

I saw a lot about jetting, etc., in the stickies, but this sounds like a bigger challenge.

John

 

[MercuryMarc]

I have tried MANY carbs on my 250
1940 - small base
1940 - large base
5200- stock
5200 - bored out the venturi - see post:
http://fordsix.com/forum/viewtopic.php?t=36105&highlight=5200+bored+venturis
Carter RBS

Keep in mind I am a novice, IMHO the best carbs were the 1940 large base manual choke and the current RBS.

Why? No bog, no stalling on Left turns, and very nice throttle response through all RPMs.

Good luck!