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Beemon

1956 Buick WCFB Rebuild

45 posts in this topic

In general, the "heat riser" passage is also used to provide a "hot spot" in the base of the intake manifold plenum to help vaporize any "liquid" fuel which might accumulate down there.  Plus it gets the intake plenum heater quicker for more efficient operation.  The reason that "racers" plug it is to keep heat out of the intake itself, other than what migrates in through other hot engine parts.

 

Modern FI engines don't have heat passages in the cylinder heads with the feedback loop operation of the injection system, so they can better compensate for "warm-up" performance with what fuel goes into the manifold itself.  Carbs can't do that.

 

The heat track in the front of the carb base pad was there to help with "carburetor icing" (where ice actually builds up on the venture in certain humid and cool atmospheric conditions.  Remember that fast-moving air has less heat, especially with atomized fuel being sprayed into it, than ambient non-moving air.  The ice would accumulate and eventually strangle the engine until it stalled.  Once thawed out, things "as normal".

 

The other thing which modern engines also have is aluminum cylinder heads (with no heat riser passage in them).  They heat quicker than cast iron, which can help lessen the need for the passage, too.  Even with the earlier cast iron heads and the heat riser passage blocked, in more temperate areas of the USA, little cold-start performance affects have been noticed, past the first minute or so or run-time.

 

BE SURE to use the correct OEM-spec carb base gasket arrangement!

 

Never did use a round table with a white table cloth in carb rebuilds!  Hope everything on there was "clean"!  The "heat trick" is a neat one, but the Dawn soak might work better for oiled ducks, to me.

 

IF, for some reason, the carb does fine on the "main system", but won't idle, check the diameter or the "low speed jet" in the bottom of the idle tubes of the venturis.  They can become partially clogged and restrict idle fuel enough that a "no idle" situation results.  As long as the throttle is on "fast idle", things will seem to work well, but as soon as "hot base idle" is desired, the engine will die.  THAT is a hard situation to track down, by observation (and my own experience)!!

 

Hoping everything works well!

 

NTX5467

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Beemon: I learned something, too. That was just a shot I had in my computer from a few months ago before I went through that carb. I can remember pulling hair out getting those linkages back together. But I just learned to make sure the whole dam piece is in the pic!

 

I always read your posts and have deduced you are just a kid, (I can say that cause I'm pushing 70) but I love your enthusiasm and the way you dive into things. It's inspirational at times. You could do a little book on you and your Buick, I guess nowadays it would be a "blog".

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1 hour ago, leon bee said:

I always read your posts and have deduced you are just a kid, (I can say that cause I'm pushing 70) but I love your enthusiasm and the way you dive into things. It's inspirational at times. You could do a little book on you and your Buick, I guess nowadays it would be a "blog".

Well technically I am 25, but to most on the forums, kid is probably adequate. :P I don't have time for a blog, but everytime I do one of these I tell myself "I'll make a Me and My Buick" thread and then forget.

 

I can see why people shelf the 4GC and replace it with a WCFB. I am more than happy with what I've built. A little rough at first at idle, but I just went up my carb cleaning hill and everything is as good as new. No float bowl flooding, either, so the original needle and seat worked great. And I pulled the sight plugs - floats are where they should be. My favorite part is no stumble at all. And I'm not sure what it about the operation of the carb it is, but the 4GC felt like a slug in comparison when opening the secondaries. It would suck air and fuel and not get on it. This carb definitely gets on it, so much that I did a right turn burnout around a corner in Low, whereas before it would give me maybe a squeak.

 

I picked up an Edelbrock electric choke at the parts store. The fast idle arm that rests on the choke thermostat is too long and I don't want to cut it. My next plan of attack is to pull the intake, tap a hole in the inspection plate, and run a hot tube from the intake to the carb. I feel this will be the best way to go on it since the exhaust manifold port is all messed up. It's getting warmer, so the choke hanging loose in the time being isn't too bad. It started up fine as I ran errands all day without the choke on.

 

18057953_10156007009920830_7696364916821

Who wore it better?

 

18033280_10156007010060830_7487120916534

18034043_10156007010180830_1883862793483

Edited by Beemon (see edit history)
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6 hours ago, Beemon said:

 I'm already planning on an electric choke since my manifold heat riser has been broken\I ripped the stuck valve out two years ago. 

The heat riser has nothing to do with choke heat. ..just fuel vaporization.  The tube from the exhaust manifold supplies hot air to the choke housing (vacuum pulls it in). I brazed a tube to the plate on the bottom of the intake manifold for a heat source..easier than dealing with the exhaust manifold.

 

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GLAD it's all better now!  The "right" carburetor, like the "right" spark plugs, can make more difference than many suspect!

 

NTX5467

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Willis, I really think it's the design of the carburetor. They were both engineered to do the same thing but I think the Carter is just better at managing modern fuels due to its imulsion tubes and rods design. 

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Fuel injection is engineering and science. Carburation is art. Swirling air at infinitely varying densities creating pressure differentials is a pretty sloppy way to get fuel into an engine. Add the variations in load demand and it is a wonder they work at all. Being able to pick up each piece on that table and describing why it is there and what it does makes it all fun.

Although, in some instances, it can be a source of constant depression.

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My sister's dog woke me up from my night shift slumber, so in a grumble I went up to NAPA and purchased kit #6101114, which is a choke stove repair kit. I didn't even bother with the crummy heat wrap and compression fittings. I cut a fitting off the choke line from my dual quad setup and flared one end of the aluminum hosing. About the only thing from the kit I really needed was the tap, which I put on a drill bit and ground down with 80 grit sandpaper until I could get it wedged into what was left of the old line. A few light taps and the aluminum tap was set in the old choke stove hole. I slid the old heat wrap off the old, broken line and ran it up to the fitting, then stuck the bare end into the choke stove and bent it accordingly. I forgot to ask about a fitting to go on the threads of the choke as it's technically still morning to me, but after about 2 and a half minutes of warm up, I set the choke so it was fully open. The best part is, you can't see the tap under the exhaust manifold, and the stock heat wrap makes it look stock. My only complaint is the tube is a loose fit inside the tap, so when I feel up for it I'm going to gunk some high temp RTV in the tap and let it goop up around the choke stove tube, giving it a good seal.

18056787_10156010630895830_4102866782879

 

This just about completes the carburetor swap. I did notice with the engine running at temp, the choke off and the air cleaner off, the pump squirt was intermittent, so I hope that works itself out soon. It was working fine initially, I'm hoping it's just a bit of crud that needs to dissolve it's way out of there.

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16 hours ago, Beemon said:

with the engine running at temp, the choke off and the air cleaner off, the pump squirt was intermittent

 

With the engine shut off do you get a solid squirt until the accelerator pump well runs dry? I had that problem with a 4GC myself and never resolved it. Looking back over all the things I did to resolve it without success, I think there may have been porosity between the pump well and a vacuum passage in the body that drew fuel from the well while running. If I had that car today I would wipe the walls of the well with solder and see if I got a solid squirt both running and shut off. It is speculation into the past but I have wasted time on other stuff, too.

 

Bernie

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I had that same problem on an old Rochester model B one barrel drove me nuts but never seemed to affect performance

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Okay so the accelerator pump stopped squirting all together now. Before I dismiss the pump, I didn't replace the check ball inside the housing. Any tips on removing the top hat and installing a new one? If it ends up being the accelerator pump, then I may be making a call to a one Carb King...

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Ben - I KNOW I explained this on these forums once, but did a search (search is almost as worthless as a Marvel carburetor since the last forum upgrade!), and I couldn't find it.

 

You have found the major issue with the Carter WCFB carburetor! Congratulations! ;)

 

The "top hat" retainer is pressed over a protrusion in the bottle of the pump well. OCCASIONALLY, a pair of needle nose pliers can be used to remove it, but generally this results in the center bar breaking out and the retainer stuck in place.

 

Carter produced two different special tools to remove this retainer. The first works maybe 50 percent of the time, and the other 50 percent results in the same result as the needle nose pliers.

 

The first tool is a slide hammer. I do not have one pictured on my website, so will attempt a verbal picture. The tool is two pieces. The first piece is simply a metal sleeve approximately 2 inches long and maybe 1/2 inch in diameter with a hole in the center. This piece is the slide hammer, and slides over the second piece. The second piece is a rod maybe 6 inches in length, maybe 1/8 inch in diameter with a cap at the top (the anvil for the slide). The O.D. of the rod is just slighly smaller than the ID of the hole in the top hat if there were no center bar. This end is slotted such that it will fit through the half moon holes in the top of the top hat, PLUS each of these two extensions have a horizontal slot milled into the extension so once the tool is inserted into the top hat, the tool may be rotated and the slots will grab the center bar. Using the slide, one can then attempt to remove the top hat.

 

The second tool works 100 percent of the time! HOWEVER: both this tool and the tool described above were fairly expensive when new, so Carter did NOT include them in any of the Carter factory tool kits; they were sold in addition to the kit. So while not made from unobtanium, they are made from very pricium. This tool also may be fabricated, but less easy than the first. You can see a picture of this one. Follow the link, and scroll down the page to T109-279:

 

http://www.thecarburetorshop.com/Carter_tools.htm

 

Now the verbal description: This tool really is a die. There are four flutes to the die, and the inside is a female pipe thread. Thus the end of the die may be threaded onto the top hat and the top hat pulled out. One can duplicate this tool (or close enough for goverment work) by using a soft rod, a male pipe tap, and then hardening the rod.

 

Of all the special tools Carter made, this tool, the rivet plug removing tool, and the various metering rod tools are the ones you just have to have if working on one of the carburetors using these functions. The others are nice, but most can be replaced by thinking outside the (tool) box. ;) 

 

Maybe one day I will have time to do a write up on special carburetor tools.

 

Good luck.

 

Jon.

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On ‎4‎/‎24‎/‎2017 at 9:12 AM, 60FlatTop said:

 

With the engine shut off do you get a solid squirt until the accelerator pump well runs dry? I had that problem with a 4GC myself and never resolved it. Looking back over all the things I did to resolve it without success, I think there may have been porosity between the pump well and a vacuum passage in the body that drew fuel from the well while running. If I had that car today I would wipe the walls of the well with solder and see if I got a solid squirt both running and shut off. It is speculation into the past but I have wasted time on other stuff, too.

 

Bernie

Bernie - there are two major causes of this symptom:

 

(1) Incorrect accelerator pump

(2) Incorrect pump discharge valve

 

Discussing (2) first: Rochester did not have as many different mass (weight) pump discharge valves as Carter, but they did use 3 or 4 different. If too light a mass were used, it is possible for the spring not to seal the ball, and fuel to syphon from the pump well causing the pump well to be empty.

 

Not all, but many of the original Rochester pumps have a ball check valve at the bottom of the pump. If present, this ball would lift under pressure, thus allowing air bubbles in the pump cylinder which were created by percolation to harmlessly escape to the area above the pump plunger.  If no check valve is present, the bubbles will create pressure in the pump cylinder under the plunger. Since the air lighter than gasoline (well, it used to be, before ethanol), the bubbles will be right under the plunger. Since the pump discharge passage is at the bottom of the pump cylinder, the pressure will cause fuel to be dispersed by the pump discharge valve, and nearly or totally deplete the pump cylinder of its charge. If there is no fuel in the cylinder, the pump doesn't pump.

 

Edit for spelling (spell check will find words which are incorrectly spelled, but not homonyms) ;)

 

Jon.

Edited by carbking (see edit history)

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John, if you were to bet money, do you think it's the accelerator pump or the check ball under the top hat? The pump shot was there after rebuild and now it's gone.

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Not a betting man. Prefer to test!

 

The pump check goes to an opening in the bottom of the bowl next to the pump well. Stick you finger over the hole and try the pump.

 

Jon.

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The 4GC's come up with a pretty good frequency on the forum. I know I have written about my day with Tom Toal, one of the quadrajet design engineers. He was retired at the time and THE guy to go to. We worked together in his garage on my '56 Olds that had the stumble on light acceleration. At one point he accused me of being a ringer some engineers had sent to yank his chain. I took that as a complement.

Tom had a GM seating tool for the check ball. It looked a lot like a rivet set with a cup the size of the ball. A couple of taps would mold the diecast seat to the shape of the ball and make a nice seat. We almost had to put a zipper on the carb, but when it was off the car it squirted fine. Put it on the car not running it squirted fine. Start the car, hot or cold, it stumbled and didn't squirt well. I have worked on a few and that is the only one I could get to work.

Most of my stuff is AFB's or FI now, except the little Cater on the Packard. Ooops, there is a 4GC on the '60, huh, I do have one.

 

Getting old and need to back off a little. I remember the last time I did the AFB on the Riviera late at night. I bought a gallon of carb cleaner at NAPA. The label said "Don't get it on you" I poured a little in a pie pan and started out carefully using a couple brushes and being neat. It wasn't long before I was wallowing in it with my hands. Then around 2AM my fingers puckered up and started looking real funny. I got a little nervous and went into the house where everyone was sleeping and washed my hands......the worked and rubbed them....... then tried different temperatures of water. And got more nervous by the minute, thinking about those safety posters at work where only the bones were left. It's a bit of a traumatic experience. Eventually they got plump and normal looking again. I was even more careful with the cleaner, for a while.

 

Life among the carburetor mechanics is not always easy.

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I don't know that I ever got a "good" pump shot from a Carter 4bbl, AFB or AVS on my Chrysler engines, especially off-idle and in small throttle opening changes.  I tried changing the pump stroke to reposition the basic pump position in the pump well, but no real difference.  The Holley pump was more solid and dependable, by comparison, as were the 2bbl carbs I had on other engines.  Never could get the Carters to "act right", but then no real off-idle performance issues, either.  I finally figured that's just the way they were and didn't worry about it as long as when I moved the accelerator pedal, good things happened.

 

I recall that in many older carb rebuild instructions, it mentioned taking a punch and a small hammer and "hammering" the check ball on the bottom of the pump well, to "reform" the check ball's "seat".  Then put a new check ball from the carb kit in place of the hammered one.  Never did use the punch as I felt there was nothing to gain from it on my carbs, but did use a new check ball.

 

I understand the merits of the leather accel pump "cup", but I personally like the later design with the "rubber" pump cup where when the pump is pushed down, the fuel underneath it pushed the cup's edge out for a better seal (and operation).  Back then, when that newer pump style came out, to me it obsoleted the leather pump "cup".  Be that as it may.

 

NTX5467

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18 hours ago, 60FlatTop said:

The 4GC's come up with a pretty good frequency on the forum. I know I have written about my day with Tom Toal, one of the quadrajet design engineers. He was retired at the time and THE guy to go to. We worked together in his garage on my '56 Olds that had the stumble on light acceleration. At one point he accused me of being a ringer some engineers had sent to yank his chain. I took that as a complement.

Tom had a GM seating tool for the check ball. It looked a lot like a rivet set with a cup the size of the ball. A couple of taps would mold the diecast seat to the shape of the ball and make a nice seat. We almost had to put a zipper on the carb, but when it was off the car it squirted fine. Put it on the car not running it squirted fine. Start the car, hot or cold, it stumbled and didn't squirt well. I have worked on a few and that is the only one I could get to work.

Most of my stuff is AFB's or FI now, except the little Cater on the Packard. Ooops, there is a 4GC on the '60, huh, I do have one.

 

Getting old and need to back off a little. I remember the last time I did the AFB on the Riviera late at night. I bought a gallon of carb cleaner at NAPA. The label said "Don't get it on you" I poured a little in a pie pan and started out carefully using a couple brushes and being neat. It wasn't long before I was wallowing in it with my hands. Then around 2AM my fingers puckered up and started looking real funny. I got a little nervous and went into the house where everyone was sleeping and washed my hands......the worked and rubbed them....... then tried different temperatures of water. And got more nervous by the minute, thinking about those safety posters at work where only the bones were left. It's a bit of a traumatic experience. Eventually they got plump and normal looking again. I was even more careful with the cleaner, for a while.

 

Life among the carburetor mechanics is not always easy.

 

Bernie - the carb cleaner washed ALL of the natural oils out of the flesh that it contacted; and your fingers probably looked shriveled. Rather than washing (assuming you had previously) you should have visited your wife's make-up kit and applied a liberal amount of hand cream to the effected area.

 

Jon.

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At 3AM, thinking my fingers would fall off, I never would have been able to relate to your experience.

 

My Wife's makeup? she just came in the house barefoot. I hope she doesn't come over here and read this. She thinks I am working.

 

Bernie

Edited by 60FlatTop (see edit history)
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