Accelerator pump piston needed for Carter wcfb 2197s

[old-tank]

I want to have one on hand before I tear the carburetor apart I have some but I don't know if they are the right ones.  I don't want yours but if you have a picture and measurements so maybe you could post that. Thanks in advance.

[old-tank]

This is in a 55 Buick...56 is probably the same.

[carbking]

Shaft is stamped 49-174.

 

Jon

[old-tank]

Thanks for your response Jon but there are no numbers.

These are what I found in a mixed bag of stuff I got from another guy.  Both are the same, one is extended one is collapsed

 

[carbking]

1.975 ~ 2.145 inches

 

Jon

[old-tank]

17 hours ago, carbking said:

1.975 ~ 2.145 inches

 

Jon

Verified! Thanks Jon.

[old-tank]

I pulled the carburetor apart today and the piston had a small tear in it making it less efficient.  However when I removed the piston the leather disintegrated.  No telling what caused that; maybe it was the 38 years that it was in use since installation.

[60FlatTop]

12 hours ago, old-tank said:

maybe it was the 38 years that it was in use since installation.

In a classified ad that would be "Recently rebuilt carburetor".

[Beemon]

Do they make rubber piston seals? 

[Barney Eaton]

Willy   I got and have used modern plastic ones for my Corvair. 

I suspect someone makes them in different sizes (bores) that can be used on various carbs. 

The material is an engineered plastic that is not attacked by todays gasoline. 

Not home so I cannot tell you the bore size of the Corvair Rochester carb. 

[old-tank]

I cannot imagine plastic or rubber being any better than leather since leather lasted 38 years.  Rubber or plastic was all that I had available on my 51 F-1 truck with the original engine and those lasted 6 months at the most even before E-10...they looked good, but were non functional.

[NTX5467]

I'm suspecting that the bore size is similar to other carbs of that brand, or other brands, too.  Just the shaft length design might be different.  Are there any carb parts websites which might have an illustrated buyer's guide section for carburetor accel pumps and such?

 

When everybody went to the "silicone" rubber pump cups, they were noted to be more efficient and better-sealing of pump cylinders, even compensating for wear, as I recall.  Easy to change, too!

 

NTX5467

[old-tank]

2 hours ago, NTX5467 said:

Easy to change, too!

Sound easy if you say it real fast/

The actual piston change is easy, but to get to it on a WCFB, 18 screws to remove the air-horn (x2 if you did not notice that the power piston fell  off the hanger) then rods to orient into the jets...

[carbking]

The auto shops just loved the neoprene, fluorelastimer, etc. artificial accelerator pumps; as they get to rebuild the carbs every 2 or 3 years rather than every 2 or 3 decades!

 

Because there are a very few individuals in the hobby today that look at "the bottom line", we offer some, not all,  rebuilding kits with the non-leather pumps, at a significantly lower price than the same kit with a leather pump. The ratio of more expensive kits with leather pumps to the other stuff is running about 15 to 1 in favor of the leather.

 

But I like the "other stuff" as well, as folks that are fed up with it become our customers   

 

Jon

[Bloo]

^^This.

 

I have torn down so many carbs years ago where the rubber pump cup was the main problem. Get it out on the bench and compare, and you see the rubber part isn't worn out. It has shrunk ever so slightly, just enough that it won't seal anymore.  Leather ones are usually reusable after soaking in a little ATF (look them over for wear).

[carbking]

2 hours ago, NTX5467 said:

I'm suspecting that the bore size is similar to other carbs of that brand, or other brands, too.  Just the shaft length design might be different.  Are there any carb parts websites which might have an illustrated buyer's guide section for carburetor accel pumps and such?

 

When everybody went to the "silicone" rubber pump cups, they were noted to be more efficient and better-sealing of pump cylinders, even compensating for wear, as I recall.  Easy to change, too!

 

NTX5467

 

Websites with illustrated parts:

 

I checked the three major manufacturers, all have online sites where NON-illustrated catalogs may be downloaded.

 

I do not know if any of these will sell to the general public; to buy from these manufacturers, we had to provide a resale tax certificate, but that was decades ago, things do change.

 

There are probably some online auto parts stores that will sell individual components, but probably do not have good (or any) illustrations.

 

Lots of items to consider when buying an accelerator pump from a picture. Just off the top of my head:

 

(A) shaft diameter (if round)

(B) cup diameter

(C) solid or articulated shaft

(D) if articulated, both overall and compressed length

(E) thimble solid or vented

(F) thimble standard or elongated

(G) shaft profile, if flat

(H) shaft attachment, round hole, square hole, or slot

(I) hole or slot dimensions

(J) cup material

 

There are probably others.

 

Jon

[Peter R.]

Pump Plunger, Rod, Spring and Retainer Assembly 64-166S or 64–180S was originally used on 2197S. Keep in mind that several other assemblies are also stamped 49-174. Measure the length.

Pictured is 64-180S, which superseded 64-166S. No clue what the difference is. Maybe different spring forces?

 

[NTX5467]

4 hours ago, old-tank said:

Sound easy if you say it real fast/

The actual piston change is easy, but to get to it on a WCFB, 18 screws to remove the air-horn (x2 if you did not notice that the power piston fell  off the hanger) then rods to orient into the jets...

The "easy to change" part was in reference to the silicone pump cup just snapping over a holding tang on the bottom of the shaft.  Not getting to that point.