| |
Click on image for the lowdown. 
====
| | |
1 members (Steelonsteel),
44
guests, and
3
robots. | | Key: Admin,
Global Mod,
Mod | | | Forums66 Topics128,090 Posts1,056,024 Members48,432 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Nov 2002 Posts: 2,766 Carburetion specialist | | Carburetion specialist Joined: Nov 2002 Posts: 2,766 | I am not going to get into this argument - I don't know!
However, a bit of information.
In 1950, Carter Carburetor released carburetor YF number 788s to replace the Rochester B on 235 CID engines with manual choke. The Carter 788s is set up for ported vacuum. This carburetor was sold through early 1952.
In mid-1952, Carter Carburetor released carburetor YF 966s to supercede YF 788s. There is a calibration change, and 966s is set up for ported vacuum. Carter suggested existing stocks of 788s be used and then 966s was to be sold to replace Rochester B's on 235 CID engines 1950-1952 with manual choke.
In 1953, Carter Carburetor released carburetor YF 2100s to be used on 1953 (BUT NOT 1952 AND EARLIER) 235 CID engines with manual choke. THE MAJOR DIFFERENCE FROM THE 966s TO THE 2100s WAS THE VACUUM TAKE-OFF IS NOW MANIFOLD VACUUM, NOT PORTED! The 2100s was continued to be sold for 1953 and newer 235 CID with manual choke through the 1956 model year. The 966s was still available for 1950-1952 engines.
In 1957, Carter Carburetor released carburetor YF 3211s for use on 1957 and newer 235 CID engines. YF 3211s also has manifold vacuum.
So, as stated earlier, I am not going to get into the ported/manifold vacuum argument; but I have always believed engineers do things for a reason.
Jon.
Good carburetion is fuelish hot airThe most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes!The Carburetor Shop | | | | | Joined: Jan 2014 Posts: 3,684 'Bolter | | 'Bolter Joined: Jan 2014 Posts: 3,684 | When we discuss manifold vs port, are we referring to the vacuum signal for the distributor advance? Or the vacuum signal for the internal workings of the carburetor?
I've heard of this issue with the YF before. My "backup" carb is a 2101s (auto choke version of 2100)...a pretty nice rebuildable core. Would have preferred a manual choke but got this one pretty cheap on eBay.
Have some other issues to resolve (ignition, etc) before I can completely give up on the "B" that's on the engine today.
The engine is a 1962 model 235. I know the 2101s isn't spec'd for this application, but given that it is designed for the right displacement and uses manifold vac like the 3211s...I am hopeful that it will work.
1951 3100
| | | | | Joined: Nov 2002 Posts: 2,766 Carburetion specialist | | Carburetion specialist Joined: Nov 2002 Posts: 2,766 | JW - the thread is about vacuum signal from the carburetor to the distributor.
As long as the CORRECT carburetor mounting gasket is used for the carburetor being used, the carburetor will take care of the correct vacuum for its internals.
Jon.
Good carburetion is fuelish hot airThe most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes!The Carburetor Shop | | |
|
|
| |
