The Stovebolt Site Forums The Shop Area Engine Shop Carburetor for 235

I have a rebuilt 235 in a 1953 one ton I’ve been working on. Getting close to starting the engine for the first time since 1978. I have a couple Rochester carburetors in poor shape. The best could probably be rebuilt, but I am basically starting with no carburetor. Starting from scratch should I go another direction? I read a lot of people say Carter, but I also read the Carter does not handle ethanol fuel well, and if it sits it could need work regularly. How about a zenith? I’m not overly concerned with original, more with something that works and is reliable.

No carburetors handle ethanol fuel well if they sit around for months not being used.. I've been driving my truck with a Carter YF since March using ethanol fuel. It works just fine. If you aren't going to drive the truck enough to use up the fuel in the tank, you need to use non-ethanol fuel exclusively regardless of what kind of carburetor you have.

If you can find a Carter YF, use it. If you can't, rebuild your best Rochester B. Make sure the body isn't warped.

You need a known good working carburetor to break-in that engine. You will be too busy attending to other problems once you start it. Feed the gas from a clean auxiliary tank and fuel hose. Don't risk using an old rusted fuel tank. If you lived near me, I would loan you my carburetor.

Carter YF 2100 with a rebuild kit made for Ethanol is preferred but they are usually $$$. The proper model Zenith would be great if you can find one. The Rochester can be made to run decent but expect a need to rebuild it in the future (parts age warping).

Do you know of a source for that kit made for ethanol?
The only issue with the YF2100 and ethanol is the accelerator pump diaphragm. I would love to find a source for an ethanol-proof one.

You can make one
I buy sheets of Viton from McMaster carr to make fuel pump and carb diaphragms
Kalrez will also work for all modern fuel blends but it’s very very expensive
Pure nitrile should also work according to most chemical compatibility references.
McMaster also has fiber re-enforced versions of these materials in different thicknesses explicitly made for our applications
-s

The problem is that those diaphragm are not flat. They are also tiny, and affixed to a tiny shaft by who knows how.

Not difficult to fabricate a new shaft and the washers on a lathe.

Not difficult to spread the end of a new shaft to expand over the lower washer.

Not difficult to have a new steam die fabricated to mold the molded (not flat) diaphragm, but you can easily buy a new (2022) loaded truck for the cost.

We have had a couple of customers try using flat diaphragms with zero success (insufficient movement of the diaphragm).

If you really want to try this, a good friend in the fuel pump kit business has suggested fiberglass-reinforced Buna N for FLAT diaphragms to be used with ethanol.

The better solution (opinion) is to start the engine every few days to assure the fuel does not totally evaporate from the carburetor (besides, more fun than just watching it sit unattended )

Jon

Well I have been using a Daytona Universal carburetor on one of my 216s for over two years. It is the best carburetor I have used on one of these engines. It gives me twice the mileage of my professionally rebuilt W1 and it was brand new and I believe made in the USA!

Guys I'm not trying to start a war.

52carl, https://quadrajetparts.com/ethanol-rated-pump-diaphragm-assembly-p-2943.html
Carter YF 2100S Pump Diaphragm Assembly part number is 203-60S
If you have doubts, give them a call and let us know what Ethanol resistant material is used.

From my memory, from past comments here, is that the Daytona UN2 (Zenith clone) is okay for 216 and 235 but is full throttle lacking on a 261.
The UN2 longevity PROOF (not just, it has worked for me) is unknown compared to Carter YF which has been around 60+ years and is still working.
Be warned there is another Asian made Zenith clone that is junk.

So it uses the Zenith design but it is updated and non of the insides look the same.

What kind of fuel economy are you getting?

My stock, non-rebuilt 216 with Carter YF gets 13-14mpg on highway/city combo driving.

bouymaker,

Thanks for the info and link for the source of the ethanol friendly rated pump diaphragm for the Carte YF.

FWIW, looking at that page source appears to list a host of other YF repair parts that may also be of use.

A useful resource!

Added one of the Quadrajet accelerator pumps to my cart and up comes a " We are temporarily closed due to unforeseen circumstances. No orders will be accepted at this time" message. Anyone know what that's about?

What company are you talking about?

Buoymaker's quadrajetparts link a few posts back.

Thank you buoymaker! I hope that their "unforeseen circumstances" get straightened out.

Looks like I got lucky when I bought mine. They were selling the same on ebay but I don't see any now.
Mine has been working well but I run non-Ethanol. I installed it case I had to run Ethanol.
I guess I have to revise my recommendation to not include the Carter YF. What a pity.

A good Zenith (not Daytona) model would be a 11275. 30mm main venturi with 196 CFM (spec posted here on Stovebolt).

I have one of those ethanol-friendly diaphragms in my YF3211S. It is on the second year currently. 4 years ago I had one I was testing but I sold the carburetor and left it in there (clumsily). I've purposefully let the carburetor go dry several times...no problems so far. And yes...I use ethanol gas. It is treated with Sta-Bil 360, and if that's what is keeping it alive, well...that's cheap protection. I bought 3 or 4 when a fellow had them on eBay, but now he only has the common black diaphragm.

Pa Farmer You could do what I do,put it on propane forklift parts,you'll get rid of those sorry liquid carbs,fuel pumps,dirty tanks and lines. No more vapor lock,sludge,oil will stay like new,wont wash your cylinders down with gasoline every morning,never cold natured again and will start with just a bump hot or cold also lugs a lot better. Use a forklift tank or two so you don't get stranded. Has just one filter you can clean with an air hose will be dry. IT'S WHAT YOU SAID...WORKS AND IS RELIABLE!!! Easy to trouble shoot too,can get home on a grill bottle. Or fight ethanol gasoline,vapor lock,dirt,flooding,diaphragms,floats and more. Takes a hose,fuel lock,vaporiser and carburetor tank in the bed. Also use HEI homemade dizzy.

carbking It amazes me what bolters will go thru to keep using this sorry liquid fuel,fight little diphragms,warps,floats,springs,shafts !! Once had a governored LP carb I learned to make one diaphragm for, well that one is hanging up full of mud dobber nests. Haven't battled any of that stuff for years nor HEI ,start run ride and drive !! Charge on to the ethanol pumps !!

Ethanol sucks but it isn't that bad. Just don't let your truck sit around loafing.

I've never owned a non-carburetted vehicle in my life. When ethanol was introduced it screwed up the original fuel pump in the Cadillac. Once that was remedied with an ethanol resistant one, it's been fine. I've been driving it for 20 years.

All the other vehicles have had carburetors rebuilt with ethanol resistant parts and ethanol hasn't caused any problems with them.

The key, however, is that vehicles using ethanol must be driven frequently and not sit around for weeks or months. My cars all work their way through the rotation and see regular weekly or daily use.

Sorry to break up the love affair for the "red" diaphragms.

After reading this thread, I called the manufacturer (one of our suppliers) to try to get more information.

Customer service informed me the red material is the same as the blue material, but with a different dye (color), and the red was discontinued.

Engineering was out this morning, so have a call in to them to see if they have a blue diaphragm (I have not seen one).

Just for the record, we have had no trouble with the black diaphragms IF the engine is started on a fairly regular basis. On daily drivers, there is no problem.

As to those who swear by the red: we have found that local blends create havoc with some materials. Using the modern poly-nitrite closed-cellular foam floats works in most locations, but locally good for 3~4 weeks. So some of these products may not be failing because of the local blend, and other diaphragms in the same local blend may also not fail.

Will report back when I have more information.

Jon

How is last week's ethanol more corrosive than tomorrow's?

Ethanol (and all alchohols) will pull moisture out of the air. If it sits too long, it'll be mostly water.

Jon, we really appreciate you looking into the diaphragm material.

Kevin, from what I read in an EPA letter, about leaving a can of E10 open to air for 200 days, the Ethanol in the gasoline binds with water (air moisture). The mixture is heavier and separates to the bottom of the tank (or gas can or container). The gasoline above gradually becomes Ethanol depleted. All this depends on time, humidity and temperature. I've seen extended length tests where the Ethanol-water mixture will eventually separate to mostly water on the bottom and a cloudy mixture layer above. The Ethanol depleted gasoline still resides on top. To give some kind of answer to Mr. Panic, since the Ethanol is still somewhat diluted, I would guess it is less corrosive.

Actually, the water would be more corrosive to the metal that carbs are cast from. Don't know about corrosivity of Ethanol to various rubber compounds, whether watered down Ethanol would be more corrosive or less so.

Tons of youtube vids showing how easy it is to remove ethanol from gas. Basically, you just add water to the gasoline, shake it up, and the ethanol, having bound to the water, sinks to the bottom leaving "pure" gas above to be siphoned out or withdrawn by whatever method you choose.

Tried it myself and was AMAZED. All pump gas in my area contains "up to 10%" ethanol. I poured 32 oz of gas (10% would be roughly 3 oz of ethanol) into a container, added 6 ounces of water, shook it up, and waited 24 hours. Had my doubts as to whether it would remove much ethanol, but was pleasantly surprised to get a full 9 ounces of water/ethanol mixture after separation.

Seeing with my own eyes how completely and how fast ethanol binds to water really makes you think. If I still lived in humid, rainy TN, I'd probably do the above process for all the gas in my stock '52 if ethanol-free gas wasn't available, which fortunately it was in 2015 when we moved to AZ. I'm not sure it's worth the effort here in the dry desert, but anywhere with high humidity, I'd say it most definitely is.

The downside of that idea is that the Ethanol depleted gasoline has a lower octane (Ethanol increases octane).
If you have pre-ignition (knocks), don't run it. You would need to add an octane booster.

That's correct.

Pure ethanol has an octane rating of 100 but behaves as if it's actually 112 octane when it's mixed with gasoline to increase the overall octane rating.

That means if you started with 87 octane fuel,the pure gasoline you're left with after separation is 84 octane. Good luck running your lawn mower on that let alone any of your vehicles.

OK - to quote a badly overworked phrase from Monday Night Football: "upon further review":

Finally was able to contact my second source (USA), and the orange diaphragms ARE available (AND expensive!). This source is using orange dye rather than blue.

I ordered a minimum order (several hundred) and should have them in stock AFTER the first of the year.

As most of you know, I do NOT sell kit components ala carte; they are sold in kits only.

Once we have received our order, we will give customers the option of the orange diaphragm kit (at extra cost) or our standard kits with the black diaphragms that have given us no trouble on daily drivers, or vehicles that use gasoline.

We have offered this option for years with conventional accelerator pumps; that is, a less expensive kit with the modern chemical pump cup, or a more expensive kit with a genuine leather pump.

Moderators: if you feel this post shouldn't be here, please delete. Since there seems to be interest in the colored pumps, I located them, and posted here.

Jon

Carbking, didn't you say that all the colors are made of the same stuff? I'm confused.

By the way, my truck has been running on ethanol with Jon's black pump since February without any problems.

My Packard has a leather pump , which is pretty much impervious to anything.

Start with 91 octane; yields about 87 which is great for old trucks.

Will the ethanol-resistant diaphragm kits will be available for my Carter YF 964S on a 216? Maybe it's the same pump, I dunno.

Quote Otto Skorzeny "Carbking, didn't you say that all the colors are made of the same stuff? I'm confused."

It is good to be confused, join the club!

Vendor 1 HAD both blue and red diaphragms which were the same material with a different colored dye. They discontinued the red dye in other diaphragm, but did not offer the YF diaphragm in other than black.
Vendor 2 has orange ones, but no blue.

Quote Skooter: "Will the ethanol-resistant diaphragm kits will be available for my Carter YF 964S on a 216? Maybe it's the same pump, I dunno."

The kits with the orange pumps will be available once I get my order. And yes, the diaphragm in the 964s is the one I ordered. Call me after the first of the year. They are SUPPOSED to be ethanol-resistant (NOT ethanol proof). In the FWIW category, neoprene (the black diaphragms) is recommended for use in ethanol by our benevolent government!

Jon

What are the orange ones made out of?

Thanks for going through the extra effort Jon.

YF-964S and YF-2100S use 203-60S according to the spec sheets.

I forgot to mention the second downside:
While one goes through a lot of effort to extract 10 gallons of 87 octane gasoline from 91 octane Ethanol gasoline, one accidentally causes a spark.
The devil just laughs and says, "welcome to my world".