1956 Rochester 4GC fuel seeping

[Beemon]

The car has been sitting for a week now since the starter went out and I just opened the hood today and noticed that both of my 1956 4GCs are seeping fluid from the blurry section of the photo (sorry it's hard to get a good picture from that angle). There are two of those cast filled holes on the accelerator pump, which I presume was filled after the passageways were machined. There was a lot more fuel than what's in the picture as I wiped it up before snapping the photo.

 

I've read horror stories that these fall out due to ethanol fuel... is that correct? Obviously there is quite a bit of seepage for sitting just a week and now that I've seen it I do recall smelling gas beforehand. The intake is yellowed below this spot on the rear carb but I always figured it was the grease I applied to the linkage...

 

 

My first thought was the screw hole above the accelerator pump, but it's dry at the base of the air horn gasket.

[old-tank]

All of the plugs on an old old 4GC should be replaced.  Maybe Jon will jump in for the proper procedure.  Mine were slobbeing but I just put ot in a box and used a Carter WCFB.

[NTX5467]

There are two things at play here . . . age (solder has probably dried out some) and ethanol (a "cleaner" that further deteriorates the solder seal compound).

 

There have been a few engine fires from this issue!  One of our (late) chapter members did an article for "The Bugle" a few years ago.  He caught his before there was a problem, but he recounted that a '56 Cadillac pulled into a weekend cruise event "smoking".  Gasoline on a hot engine!  Fire extinguishers appeared out of nowhere to put the fire out.

 

More visible on the carbs with a "ball" staked in the end of a drilled passage, which is sealed on the outside of the carb.

 

This situation is something that EVERYBODY should be aware of!.  Default mode is to fix it so it doesn't happen again!  ALSO watch the "weep hole" of the fuel pump, too!!

 

NTX5467

Edited August 11, 2016 by NTX5467 (see edit history)

[carbking]

This CAN be an issue, but rarely is. If it is, obviously, it needs to be fixed.

 

What we are discussing are passage plugs.

 

Carter used copper in the 1930's and 1940's and then superceded the copper plugs with aluminum (probably due to cost, but I don't have that is writing). The Carter plugs were tapered, some had a starting diameter which was slightly smaller than the full diameter. The Carter plugs rarely leak, but after 60 or so years......nothing is permanent. Removing the Carter plugs is difficult. Using the original tool makes life easier, but expect to chop the heads off a few before you really master the technique (don't ask how I know). And once you chop off the head, you get to cautiously drill out the remains of the old plug! While this thread is not meant to be a sales pitch, if you follow the link below, then scroll down to T-109-43, you can see what the special tool looks like: http://www.thecarburetorshop.com/Carter_tools.htm

 

Replacing the Carter plugs is a simple matter of acquiring the correct size plugs, and using a drift punch and a hammer to install the new plugs (obviously after removing the old ones). If you don't wish to buy the correct plugs, read further.

 

Rochester, Stromberg and Zenith used lead balls. They are much easier to remove than the Carter tapered plugs, as the lead is sufficiently soft one can drill a small hole through the center, and pry out the ball using an ice pick. The lead balls give more trouble than the Carter aluminum or copper plugs when used with ethanol fuel, plus as they are significantly softer, they tend to release more easily, so may tend to give more trouble in 60 year old carburetors even if ethanol is not used.

 

Lead balls may be purchased, but those readers that are fishermen (or fisherwomen, got to be politically correct these days) will recognize the resemblence to the split shot sinker. The split shot sinker may be used. Simply get one that is somewhat larger than the hole, use a drift punch and hammer, and force it into the passage.

 

Jon.

Edited August 12, 2016 by carbking (see edit history)

[NTX5467]

Are the lead balls just "forced" into place (dry) or should there be some kind of sealer/solder that is the final seal procedure?  Just curious.  On some carbs, it looks line the edge of the bowl is "bent over" the plug, with some sort of sealing agent.

 

Thanks,

NTX5467

 

 

[JohnD1956]

Also, if a carb is not leaking now, is it advisable to try and put a coat of JB weld or some other sealer ( what would you recommend) over the top surface of each plug now?

[carbking]

Stromberg just drove the plugs into the holes.

 

I too have seen what appears to be a lip over the ball, but believe it just to be an oxidation ring.

 

The tests we have done on JB Weld with gasoline have always ended in failure if the gasoline touched the JB Weld. If it were mine, and it were leaking, I would replace the plugs. If it were not leaking, I would just inspect periodically. The plug is going to seep long before it falls out. When it starts seeping, replace.

 

Personally, but this may not be true for others, if plugs needed replacing I would replace with Carter aluminum tapered plugs with a drop of blue Loctite. But then I have the plugs, so availability for me is not the issue it might be for others. The split shot sinkers do work, which is why I mentioned them earlier. I have never tried the Loctite with lead, so do not know how it would work.

 

Once in a blue moon, I have needed a couple of plugs of a size I did not have, and simply machined them on a lathe. As I have stated previously, other than the obvious wrenches, pliers, and screwdrivers, etc., a hobby lathe and an a hobby vertical mill are two of the earliest tools which the enthusiast should buy.

 

Jon.

Edited August 13, 2016 by carbking (see edit history)

[JohnD1956]

Thanks Jon.

[NTX5467]

What about using some lead-based solder, dripped onto the outer surface of the plugged hole (for the lead shot)? 

Do the plugs normally come out "clean" or might some corrosion be present on their sealing surface?  If the sealing surface might be compromised, how to compensate or clean it?

 

Thanks for your information, Jon!

 

NTX5467

[carbking]

Willis - as I have never had issues with using the tapered plugs, I have never tried the solder, so don't know. Have not really seen any issues with the sealing surfaces being compromised, just the lead plugs with the ethanol fuel. The Carter plugs come out clean. Since I dig out the lead balls, they come out in pieces, so cannot really give an answer.

 

I wonder if some of the failures may be due to individuals using chemicals on these castings that the castings were not designed to withstand. Don't know, just wondering. See all kinds of chemicals suggested on some of the various forums that were not used by the manufacturers. Not enough of a chemist to know whether damage might be done or not.

 

Jon.

[Beemon]

Thanks for all the information. My father happens to be a bass fisherman so he knows exactly what you're talking about. 

 

I can't comment on the history of my second carb but I do know that my original unit was dipped in chem cleaner three times. I've only ever cleaned them with compressed air and dawn dish soap. Every other fill up I dump seafoam into the tank so I do not know if that would do anything to the lead and solder or not. 

 

As for dissolving lead or solder, I can get in contact with the chemistry department at the college and see if we can find some type of reagent in modern chem dips or sprays. 

[NTX5467]

Thanks for that reply, Jon.  If there was not any sealing/retention solder in the ball seat (which would be eroded/"cleaned" by the ethanol), then are we seeing a situation where the seal balls are physically shrinking/deteriorating with age and/or exposure to ethanol?  Or might the many hot/cold cycles be re-conforming the lead seal balls enough for a seep to start (and then possibly get worse)?  Or might the ethanol's corrosive characteristics also be operative on lead as it can be on other fuel system "metals"?  Just wondering .

 

I realize that most of the particular drilled passages are in "no pressure" fuel areas.  The only force against them is the weight of the fuel in the float bowl, typically.  That makes the sealing function easier. .

 

NTX5467

[60FlatTop]

Interesting string of comments. I am an old boiler guy and although there aren't many riveted lap joint boilers left a few have come my way. On boilers the metal to metal seal is called caulking and we do it with special round head chisels to mechanically create a molecular bond. Now that the thought is in my head I think I will make up a couple, maybe a 3/16 and a 1/4, straight and cupped. I'll put them in my Murphy's tool box- Murphy's Law: if you have a special tool you will never need it.

Bernie

Edited August 14, 2016 by 60FlatTop (see edit history)

[NTX5467]

In the 1980s, I attended a Holley carb seminar put on by a regional hot rod parts vendor.  The Holley engineer commented that gaskets are needed to compensate for "poor machine work (either surface texture, flatness, or similar).  I found that interesting as even on very good machined surfaces, it seemed to me that gaskets would be needed.  But as it turns out, not that many automotive machined surfaces are really machined that well.  This can be a cost-effectiveness issue.  More usual to spend less on machine work and add a little cost for a good gasket.  Gasket technology is still a seemingly constantly-evolving industry.  In many cases, gaskets are to protect against galvanic reactions of dissimilar metals, harder vs. softer, etc.

 

Thanks for that illustration and comments, Bernie!  Interesting how many things have evolved as technology became more prevalent.

 

NTX5467

 

[Beemon]

I'm at a place in the road that goes four ways in regards to this situation. 

 

1. Disassemble the 4GCs, pull every lead ball and reassemble.

2. Find a WCFB as everyone else with this issue does, lose the dual quads. 

3. Mount an E-clone, lose the dual quads. 

4. Buy Holleys, keep the dual quads. 

 

3 and 4 I'm advised against doing,  but 3 has had success on these forums and others. 2 is the easiest but the WCFB is rare for me locally and nothing online at the moment. To be honest, I don't feel comfortable doing 1. No one else has done it on any forum I've searched. I'm sure it's easy but you're playing with irreplaceable 60 year old parts with machined passageways and I don't want to risk it. Local carb shop said the same thing and the machine shop wants more than an E-clone per carb. 

 

As far as I know,  both these carbs have never seen ethanol until they were put on my Buick - my first one last year and my second one a few months ago, both seeping. So assuming I make these repairs, who's to say I'll be doing them again in six months? I've never heard of this issue with a WCFB, which is why I've been searching for one. I've only been able to find a 55 with a weird number tag, will have to go back out and check it again but it was also missing the coke arm, and a 53 with a V8. Another yard has a 54 but the owner will only sell the complete engine and not parts. 

 

What's the difference between 53, 54, 55 and 56? Would I be able to salvage a choke arm off the 53 and put it onto the 55? Would a 55 WCFB even perform well on a 56 322?

 

I would be more inclined to attempt these repairs to the 4GC if I had a back up but I don't. Yes I have two of them, but then if I pull one I pull both, etc. ...

Edited August 17, 2016 by Beemon (see edit history)

[NTX5467]

I know that one of our (late) chapter members did that repair on his '58 Super and it worked well.  He did an article for "The Bugle" about it, but that was probably about 4 years ago (now).  If I'm correct on this, CarbKing would know specifically, there is only one ball/seal that has a problem.  It seals a drilled passage which leads to the float bowl, which is what makes it highly-important to be effectively sealed.  There are some other ball locations (possibly at the bottom of the accelerator pump well), but they are not "sealing" balls.

 

I highly suspect that the WCFB and 4GC have very similar air flow capabilities.  The main difference might be that one might have crisper throttle response off-idle and such, one might get a slightly better fuel economy, or similar.  In other words, not much difference.

 

There were AFBS from later model Buicks, possibly in the later 1950s and earlier 1960s?  They would be for larger 364 and 401 V-8s, though, so their metering calibrations might need some massaging for the smaller 322 application.  Their cfm rating might be closer to 550cfm, which is probably about 100 more than the 4GC or WCFB (Will Carter Four Barrel) carbs.

 

The 2x4 carb set-up might look neat, but you can get almost the same power from a good 4bbl set-up (unless there are other modifications to the engine which would need the additional airflow capabilities).  Your call on that.

 

Thanks for keeping us posted!

NTX5467

Edited August 17, 2016 by NTX5467 (see edit history)

[Beemon]

The 4GC and WCFB should be nearly identical. By difference I meant difference in 322 production years from 1953 to 1956. The AFB pattern of 1957 and later is different. 

 

I really pride myself in setting up a clean 2x4 setup I just hate to take it off. But I also don't want an engine fire or any other hazards. The car is grounded for the time being other than a 5 min startup and idle to keep the gas fresh in the bowls. 

 

So far I've narrowed down the seeping to the accelerator pump plugs and the big plug behind the accelerator arm. The two on the front of the bowl at the bottom are dry.

Edited August 17, 2016 by Beemon (see edit history)

[old-tank]

Just do the plugs

[60FlatTop]

Did you try using a blunt tool to massage the existing plugs into seating? It would be the first step. That lead and zinc body should roll right in there.

 

If you look into the details, that little check ball at the bottom of the accelerator pump well is steel. GM made a special seating tool for it, a hex shaft with a rounded cup at the bottom. You press it against the ball and give it a little whack with a hammer to seat it. That should be an indication of how malleable the material is. 

 

Dual carbs? I think you could get it running really good on one carb first. Then gently pry one of the plugs from a second carb and put it in a glass of water in the kitchen window over the sink. It might sprout. Once the carb sprout grows enough to transplant put it on the engine. Be patient and your dual carb issues will kinda go away.

Bernie

[NTX5467]

Don't use coconut water . . . it might look like a candy bar commercial!

[EmTee]

These are Cadillac, but possibly interchangeable...?

 

http://syracuse.craigslist.org/pts/5685735503.html

[Beemon]

If there's one thing I've learned from speaking with Jon (there's been many), both on the telephone and from posts on the forums, is that every carburetor has different sized orifices and passageways engineered specifically for that model year engine. $600 really is a steal for a setup like that, too bad it doesn't come with the bat wing air cleaner.

 

I put this undertaking on the back burner, put the single carb manifold back on the engine with the best of the two carbs and garaged it for the rest of the summer unless I'm going out to a cruise in. I just don't have the tools to drill the passageways with the precision I need. The air horn passages are not lead balls but tapered cylinders and the tiny passageways look to be plugged with small game shot pellets.

[carbking]

One reason the price on the Caddy dual-quad is so cheap is that the correct original chokes are missing. To the Cadillac restorer that is doing everything correct, that adds about $1k per choke! To someone that isn't interested in original, aftermarket chokes will actually function BETTER than the originals, and are MUCH cheaper!

 

The Caddy engine was a 365 CID.

 

Might have to enlarge the idle jets, and possibly slightly larger primary main jets, but if you want WCFB's, probably worth a look.

 

Jon.

Edited August 25, 2016 by carbking (see edit history)