Aaron65 Posted October 29, 2016 Share Posted October 29, 2016 (edited) A few weeks ago, I posted about some WCDs I found at the swap meet... http://forums.aaca.org/topic/282918-straight-8-carter-with-holes/ I decided to rebuild and try the complete one on my '53 Special, which I determined by the numbers on the base and by the metering rods was a 2179s from a 1955 Special. I ordered a kit (the carb says WCD on it) from Bob's, but as I was putting it together, I noticed the accelerator pump was greater in diameter and shorter than the one that came in the kit. Sure enough, I pulled the pump from the "holey" carb, and it was smaller like the one that came with the kit. Did Carter try some different designs in the mid-1950s? The numbers all seem to match up on this carb, so I don't THINK it's a Frankencarb, but as it stands, I'm out about 50 bucks for the carb kit and have nothing to show for it. Any ideas from obscure carb people? For those with time on their hands, the base is 1165, the metering rods are 75-1138, and the numbers on the main casting are 950 and 6-726. Edited October 29, 2016 by Aaron65 (see edit history) Link to comment Share on other sites More sharing options...
carbking Posted October 30, 2016 Share Posted October 30, 2016 Over the years, Carter has used at least 5 different diameter accelerator pumps, and many different lengths and articulations. One "trick" racers used with Carter carbs was to bore the pump cylinder oversize; and use a shorter and larger diameter pump. Both the larger diameter pump well and the shorter pump would increase the pump stroke. Very rarely seen, but occasionally..... Also, this trick occasionally used to "save" a correct carburetor with pitted pump cylinder. Another way is to bore the cylinder oversize and insert a brass sleeve. Then original parts will work. Jon. 2 Link to comment Share on other sites More sharing options...
Aaron65 Posted October 30, 2016 Author Share Posted October 30, 2016 Here's a comparison between the two carbs. Picture 001 is the 1955 carb that I'm trying to use, and the scaly carb is the "school carb" that seems to have the correct accelerator pump bore. Both are about the same diameter at the top of the bore, but the school carb is the correct size as the bore continues down. I don't see any evidence of machining on the first carb; after all, there should be evidence near those three "tangs" at the bottom of the bore. I wonder if this is just a poor orphaned carb that Carter tried something on for some reason. Link to comment Share on other sites More sharing options...
Aaron65 Posted October 30, 2016 Author Share Posted October 30, 2016 Here are the two accelerator pumps. Link to comment Share on other sites More sharing options...
NTX5467 Posted October 30, 2016 Share Posted October 30, 2016 The three "tangs" are probably there as "travel limiters" to keep the pump plunger from bottoming-out against the carb body itself or the insert at the bottom of the pump bore. The pump, noticing the diameter of the bottom section, would be specific to the pump's cylinder bore. Other than the obvious length of the pump shaft (the upper section), the pump cup diameter would need to match the carb body's pump cylinder. At this point in time, the carb kit operatives might have put "the most common" pump in their kit? Unfortunately, that doesn't help much if it doesn't fit your particular carb. The main thing would be the diameter, I suspect, as you could shorten and drill another hole for the upper section, if needed, but that lower section could be an issue. Please keep us posted on your progress. NTX5467. Link to comment Share on other sites More sharing options...
Aaron65 Posted October 30, 2016 Author Share Posted October 30, 2016 The diameter is the same as an AFB pump (which I have lying around), but an AFB pump is longer. I'll take a look to see if I could modify it. Aren't old carburetors fun? Link to comment Share on other sites More sharing options...
carbking Posted October 31, 2016 Share Posted October 31, 2016 Do the bodies have the same casting numbers? The first carb is marked 1 3/16 for the venturii, but cannot read that on the second body. Jon. Link to comment Share on other sites More sharing options...
Aaron65 Posted October 31, 2016 Author Share Posted October 31, 2016 (edited) The other carb has a 1 1/16" venturi; that one is (I believe) a 725s, so they are NOT the same casting numbers. From everything I've been able to find, however, all WCDs should have the same accelerator pumps, but it sounds like it's not that simple! I started modifying an AFB pump to fit, but the clip that holds the spring to the pump itself doesn't allow enough return travel before hitting the carb lid, so there's no way I can get enough adjustment out of it. Drat! Edited October 31, 2016 by Aaron65 (see edit history) Link to comment Share on other sites More sharing options...
Aaron65 Posted October 31, 2016 Author Share Posted October 31, 2016 Well, what do you know? I looked at the part number on the accelerator pump (49-164), and I found a NOS one on eBay for $13 shipped. Looks like all might not be lost after all. Of course, this is a carb I don't really need on a car that already runs reasonably well, but what's life if not for a little bit of whimsy? Link to comment Share on other sites More sharing options...
carbking Posted October 31, 2016 Share Posted October 31, 2016 BE CAREFUL! 49-164 is the part number for the upper part of the pump stem, NOT THE PUMP! It was used with both diameters. Carter 725s takes pump 64-126s Carter 2179s takes pump 64-159s Jon. Link to comment Share on other sites More sharing options...
Aaron65 Posted October 31, 2016 Author Share Posted October 31, 2016 The seller included length and width measurements, which both matched the pump that came out of the 2179s. I couldn't find any numbers on the pump itself, however. Link to comment Share on other sites More sharing options...
carbking Posted November 1, 2016 Share Posted November 1, 2016 (edited) Quote Aaron "The other carb has a 1 1/16" venturi; that one is (I believe) a 725s, so they are NOT the same casting numbers. From everything I've been able to find, however, all WCDs should have the same accelerator pumps, but it sounds like it's not that simple! " End quote. Aaron - Carter type WCD carbs were used on engines from 195 CID to 427 CID. The larger engines require a larger pump shot. Carter accomplished different pump shots by: (a) different diameter pumps, and (b) different length pumps. Changing either changes the volume of fuel in the pump well to be displaced by the pump. As mentioned previously, this was a tuning "trick" used by the racers, and some enthusiasts with deep pockets raced Allards with Cad engines, using WCD carbs. Jon. Edited November 1, 2016 by carbking (see edit history) 1 Link to comment Share on other sites More sharing options...
vindictive Posted April 5, 2019 Share Posted April 5, 2019 Reviving an old thread here, but I ran into the same issue working on a 2179s WCD. The kit I purchased came with an accelerator pump that was too small to fit in the diameter of the pump bore, and a bit longer. Everything else in the kit looked right. I bought the kit from CARS which had it listed for 1950-1955 Buick WCD, even identifying the 2179s model in the fitment details. I found this thread while researching the discrepancy. Then I went directly to the kit manufacturers website, Daytona Parts Co. They have a separate kit listed for the 1955 Carter WCD 2179s that is different, so I contacted them and inquired about the difference. Here's the response I got. Yes, they sent you the wrong kit. Your 2179s takes the large accel pump in kit #109A. All other parts in the kit you received should be correct. Let me know your address and can send you a correct accel pump at no charge. If you would, please phone CARS and alert them that the 55 Buicks equipped with WCD carburetor #2179s only (1955 Buick 40 series) takes the carburetor kit #109A. I have attached photos of the two pumps together to show the difference. Hopefully this will help the next guy. 4 1 Link to comment Share on other sites More sharing options...
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