Carter BB Carburator rebuild tip

[Pep48]

I came across this rebuild tip from the Cascade Pacific Plymouth Club

https://www.cascadepacificplymouth.org/500-CarterBBCarburetors.html

 

[Tom Skinner]

Pep48,

Great Tips for Carburetor Repair!

Merry Christmas!

[Ivan_B]

So the tip is to sand down the cap and bowl on a level base? Depending upon the magnitude of the observed curvature, compressing the cap edges between two metal plates in a vise could also be a solution. This is mostly useful for reducing large gaps. For the small ones, on the contrary, using some gas-resistant sealant allows compensating for the uneven "landscape" without mechanical alterations 😉

[FarmerJon]

2 hours ago, Ivan_B said:

So the tip is to sand down the cap and bowl on a level base? Depending upon the magnitude of the observed curvature, compressing the cap edges between two metal plates in a vise could also be a solution. This is mostly useful for reducing large gaps. For the small ones, on the contrary, using some gas-resistant sealant allows compensating for the uneven "landscape" without mechanical alterations 😉

The problem with using sealant is that it makes it difficult to remove the top after applying. Seems like no big deal, but if you ever need to make a float adjustment, prime a dry carb after winter storage, unstick the vacuum piston, or for the hot rodders among us, change jets, It really sucks to replace a lid gasket every time you have it open. It is also possible to bend the lid when prying it off of a sealed surface.

 

Just make the flat parts, that are supposed to be flat, flat. Its no big deal.

 

 

[Tom Skinner]

FarmerJon has a point there IvanB.

I have worked with these Carter Ball and Ball Single Downdraft Carbs for 50 years and tried straightening the Warped Horns multiple times.

Bumping them in a vice helps but heat from the engine manifold will usually put them back warped again, sanding them flat on glass works.

Often times finding a donor Carb to Frankenstein a Horn from is the answer. Gasket Sealer isn't something I would do, its messy and a pain

to deal with going forward without really resolving the problem - gas leaks down onto the hot manifold from in this case because of is a Warped Air Horn surface.

One must endeavor to bring it back Flat and true to its mating surface to the top of the Body of the Carb.

Only then can one lift the horn off to set the float height right or clean or adjust the Pump Connector Link or Plunger or Step up Jets etc. without hassle.

This is just my humble opinion

Tom

[Ivan_B]

I don't know, never had issues with a little sealant on the gaskets. Just use the non-hardening one, so that you can remove it, later on. Wipe the surfaces with alcohol, before re-applying. No mess, good effect. I guess, I just do not take my carbs apart, very often 🙂

[Sam Buchanan]

There are valid reasons why an essential step in rebuilding an engine is decking the head and block......some surfaces need to be FLAT for proper sealing. Same with the carb body and top, especially since they are made of low density material that easily warps and depend on a limited number of widely spaced screws for attachment. The glass/sandpaper technique is great for those of us who don't have access to a mill. It also works well for getting a stubborn thermostat housing to seal properly.

[Ivan_B]

39 minutes ago, Sam Buchanan said:

It also works well for getting a stubborn thermostat housing to seal properly.

Permatex #2 (as the gasket dressing) works just as well 😆

I do not believe that the engine head is a good analogy, here, since it experiences quite different working conditions in comparison to those endured by your average carburetor or thermostat housing.

Sure, you can attempt to get perfectly straight/matching surfaces, or you can use some sealant with the same results. I am certainly not attempting to discourage anyone from having well-fitted engine parts, just offering some alternatives 😅

[Sam Buchanan]

We all must decide to what standard we are going to seek to achieve when maintaining our old cars. Some will be content with gluing the thing together while others will want to replicate original tolerances as much as practical. The carefully assembled components are going to yield superior service every time.

[Ivan_B]

I respectfully disagree with the above statement, as it appears to, somehow, attribute the use of sealants to a poorer workmanship standards and inferior service

[Art Bailey]

The suggestion given to me by the gentleman at The Carburetor Shop in Eldon, Miss. was to clamp the float bowl lid to a flat steel plate with c clamps. Don't crank until it's flat, but start with just enough pressure to hold it in place. Put it into a toaster oven for a couple minutes (forgotten the exact temp), pull it out, give the clamps a turn, repeat until flat. I haven't yet done this, but I like this idea better than removing material. 

 

 

 

 

[Ivan_B]

Heat is useful when bending metals, in general... Do we have engineers, here? Assuming that we do not have heat-sensitive parts, inside, would it be of any benefit to bake the entire assembled carb to do "stress" relief? Or would that be a waste of time since it is constantly going through heat cycles with the engine?

[Sam Buchanan]

2 hours ago, Ivan_B said:

I respectfully disagree with the above statement, as it appears to, somehow, attribute the use of sealants to a poorer workmanship standards and inferior service

You are certainly free to disagree with anything I post. But we need to accept as fact that using a sealant as a bandaid to compensate for mating surfaces that aren’t true is definitely a “poorer workmanship standard”, and in the long term it will result in inferior service. It seems as if the glass and sandpaper shop technique is something you hadn’t seen before, but rest assured this is a method that has been in common use for……since back in the steam age? I saw it in vintage motorcycle repair manuals over 50 years ago.

 

Once again, we decide to what standards we wish to work. I’ve certainly done my share of gluing things together but I also know there is a superior  method…….replicating the tight tolerances the parts possessed when originally manufactured.

[Sam Buchanan]

2 hours ago, Art Bailey said:

The suggestion given to me by the gentleman at The Carburetor Shop in Eldon, Miss. was to clamp the float bowl lid to a flat steel plate with c clamps. Don't crank until it's flat, but start with just enough pressure to hold it in place. Put it into a toaster oven for a couple minutes (forgotten the exact temp), pull it out, give the clamps a turn, repeat until flat. I haven't yet done this, but I like this idea better than removing material. 

 

Just for clarification, truing up the carb mating surfaces is usually achieved with a tiny amount of material loss, probably no more than a couple thousandths of an inch. This is sufficient to get the gasket to function properly.

[FarmerJon]

1 hour ago, Sam Buchanan said:

You are certainly free to disagree with anything I post. But we need to accept as fact that using a sealant as a bandaid to compensate for mating surfaces that aren’t true is definitely a “poorer workmanship standard”, and in the long term it will result in inferior service. It seems as if the glass and sandpaper shop technique is something you hadn’t seen before, but rest assured this is a method that has been in common use for……since back in the steam age? I saw it in vintage motorcycle repair manuals over 50 years ago.

 

Once again, we decide to what standards we wish to work. I’ve certainly done my share of gluing things together but I also know there is a superior  method…….replicating the tight tolerances the parts possessed when originally manufactured.

I think the part that I highlighted is crucial. It isn't poor workmanship to use sealants on in-spec surfaces. I will often stone a surface flat, then use an appropriate sealant on the (actual gasket material) gasket, especially if it is an assembly that I hope to never open again or is below an oil/fuel/coolant level. Oil pans, transmissions, rear ends. 

Anaerobic sealant is nice for installing lip seals, to insure oil cannot seep past the outer seal case.

 

I do occasionally wonder how "tight" the original tolerances were on some of these parts. These carb lids probably started out only but so flat, and after being installed and the first few heat cycles, they can get out of hand.

There is a reason that many hot rodders (and a few manufacturers) back in the day preferred to build on "seasoned" engine blocks. Foundry technology has greatly improved in the last 100 years, even though the workforce of tradesmen has drastically declined.

3 hours ago, Ivan_B said:

I respectfully disagree with the above statement, as it appears to, somehow, attribute the use of sealants to a poorer workmanship standards and inferior service

 

Edited Thursday at 08:31 PM by FarmerJon

[Ivan_B]

2 hours ago, Sam Buchanan said:

But we need to accept as fact that using a sealant as a bandaid to compensate for mating surfaces that aren’t true is definitely a “poorer workmanship standard”, and in the long term it will result in inferior service.

 

I wrote an elaborate response to this, but then decided not to post it. Enough has been said already.

 

1 hour ago, FarmerJon said:

I do occasionally wonder how "tight" the original tolerances were on some of these parts.

They weren't If anything, the tolerances are probably tighter in modern vehicles and sealants are often recommended to be used by the OEM, these days, because fitting the pieces without them is either impossible or impractical. For lack of better analogy, the windshield on new cars is held by a sealant... 😅 Of course, they were not available back in the days so all sorts of machinery was likely more prone to being not perfectly sealed.

 

1 hour ago, FarmerJon said:

There is a reason that many hot rodders (and a few manufacturers) back in the day preferred to build on "seasoned" engine blocks.

That's true. I watched a documentary where a 50-s engine factory was mixing all sorts of additives into the engine block iron in attempts to improve its properties against cracking, warping, internal tension... Very interesting process for a lay person

Edited Thursday at 09:58 PM by Ivan_B

[Loren]

On another topic for carburetor repair.

Whenever you take a carburetor apart from an engine that was running, shake the float.

Sometimes they develop a pin hole and they fill with fuel. There's some debate as to why this happens but I don't think it matters. Only the detection and the repair matter.

If you suspect fuel in the float get a pair of pliers and hold the float in them then take a match to the float.

When you heat it the fuel will want to come out and it will identify where the hole is.

Note where the hole is and continue heating with the hole on the bottom till there's no more fuel in the float.

Now you can repair the hole with a soldering iron and electronic solder.

In the good old days they sold a lot of floats, then they went to the black foam plastic floats.

Those days are gone but it's no big deal to repair a float that has only a single hole.

[desoto1939]

Loren: I had an issue where I could not get my carb and my 39 desoto to idle properly. I took my original carb and a couple of replacements and a NOS replacement carb to a Carb rebuilder. Put the old carb on his engine and it imediatle flooded his engine. Then put on the NOS one and it ran perfectly with a little adjustment.

 

When I had the old carb off the maniflod i had noticed that there was raw fuel in the intake maniflod of approc 1/8-1/4 inch of fuel. This was an idication that the carb was flooding and after running the car in the summer it was alwasy so hard to restart a hot engine. Thought it was the ethanol gas issue.  When I toke the old carb apart and rebuilding it I picked up the float and shook it and noticed a clunking feeling in the float. There was gas in the float. So this was making the level in the bowel seem to be alwasys wanting more gas and was flooding the carb and this did not permit the fuel to vaporize to get the car started whn hot.

 

Problem has been solved for my 39 Desoto.

 

Rich hartung

desoto1939@aol.com 

[Ivan_B]

I also had a leaking float, when I got the car. Dipping it into boiling water lets you know where the hole is 😉

[Sniper]

10 hours ago, Ivan_B said:

Dipping it into boiling water lets you know where the hole is

 

That is a fairly esoteric statement.  Care to elucidate upon how it shows you where the hole is?

[Ivan_B]

Come on, you've never done that? 😅 It starts bubbling, profusely, right out of the hole (assuming that you've already managed to shake/drain/evaporate some gas out of it, and it has some air inside). After you solder the hole, this is also how you check the float to make sure that it is watertight.

Edited 13 hours ago by Ivan_B

[TodFitch]

2 hours ago, Ivan_B said:

Come on, you've never done that? 😅 It starts bubbling, profusely, right out of the hole (assuming that you've already managed to shake/drain/evaporate some gas out of it, and it has some air inside). After you solder the hole, this is also how you check the float to make sure that it is watertight.

That is how I’ve done it. And I have also used that technique on the old style brass floats they used to have on fuel tank sending units.

[Art Bailey]

22 hours ago, Sam Buchanan said:

Just for clarification, truing up the carb mating surfaces is usually achieved with a tiny amount of material loss, probably no more than a couple thousandths of an inch. This is sufficient to get the gasket to function properly.

Probably the case for most, but the EV1 or EV2 that are on my car were known for having twisted float bowl lids, right out of the factory, according to the guy at the Carb Shop. Just for kicks, I grabbed two of them and put them on my drill press table, to see how many feeler gauges I could shove under the right corner, looking down the throat with the float bowl closest to me. Both rocked noticeably. One had a gap of .02, the other almost 3 hundredths. Since it's clearly a twist and not just extra material causing the gap, my unscientific, amateur wild-a** guess would be that it'd be better to pull it down gradually using mild heat, rather than lapping. If i were dealing with a gap of just a couple thou, then I'd lap.

Edited 9 hours ago by Art Bailey

[Sniper]

4 hours ago, Ivan_B said:

Come on, you've never done that? 😅 It starts bubbling, profusely, right out of the hole (assuming that you've already managed to shake/drain/evaporate some gas out of it, and it has some air inside). After you solder the hole, this is also how you check the float to make sure that it is watertight.

 

So you are saying you do not want a roiling boil then?

 

All you really need is some very hot water, if it's boiling profusely you won't see the float bubbling.

[Tom Skinner]

OK,

For those that want to straighten their Carb Horns, from: Collector Car Restoration Bible, by Matt Joseph, Copyright 2005, Pages 166, and 167. Edited for brevity by me.

"Warped Bowl Covers can be Hammered Straight, Heating a Bowl Cover to 350 Degrees in an oven for 30 minutes and C Clamping it to a piece of Hardwood in increments.

Tightening it down slowly - go easy. Also soaking the Bowl Gasket in Kerosene before installation causing it to swell. Tightening the Carb screws in careful stages down to 16 -24 OZ each (I don't even know how to do this). So there you go everybody has their own solution. I sanded mine on glass, didn't take much off and put a new gasket on.

Wala no leaks. So I guess instead of us being obstinate about the method used "Its whatever floats your skirt" LOL

Tom