The Stovebolt Site Forums The Shop Area Engine Shop Best carb

I’m running a 216 cid. Chevy 3600

Not impressed with the rebuilt Rochester one barrel.

Is there a better carb that will get a little better gas mileage and run better in general?

Thx Don

I have never run a Rochester. When I bought my 53 3100, somebody had already changed it to a Carter YF. I have had really good luck with it. Doesn't seem to have the leaking issues that I hear from guys that have the Rochester B. I am sure there are a number of "bolters" out there, that have a lot more experience than I. Just my 2 cents worth. Hope you are able to find something works better for you.

Rugo

I had a '49 Carter W-1 on my '47 216. It was a rebuild and it worked well for a while but I think ethanol got to it and it had trouble idling, stalled a lot, seem to lose power in the engine. I got a Rochester B from a former Stovebolter (Mr. Lang), rebuilt it and the truck has never run better. I'm aware of the shortcomings of the B but for now I'll use it until I put together a rebuilt 235. Check out Langdon's Stovebolt. (But only if you're not worried about original look.)

Most folks here will recommend the Carter. I have run Carter's on other engines and they all worked very good so if you're gonna replace the carb look at a Carter. Carter made many different models, you can do a search for "carbking" and Carter as he put together a very detailed Carter application list. He may be along.

re. the Roch B. Sounds like the power piston isn't working properly or probably not working at all. It works off of vacuum to allow more fuel into the venturi when the engine is under load. If it sticks "open" it'll allow too much fuel at all times, i.e. poor MPG.
If it sticks "closed" it'll never allow more fuel when needed, i.e. low power.
Make sure the carb to manifold gasket has a hole in it to line with the vacuum ports at the bottm of the carb and in the insulator between the carb and manifold. This is where the power pistons control vacuum comes form.

I run a Roch B on a 49 216 and it performs pretty good. The 3100 avg's nearly 13 mpg and it'll pull hills in high gear and accelerate upto 65 to pass (I don't keep it there long tho).
My 49 was a one owner and was pretty much stock so that many contribute to the Roch B working as good as it does.

Good luck

Different folks will have different suggestions.

My favorites:

216
Carter W-1, Carter YF, Stromberg B, Zenith 28 types.
There are many different individual carbs of each type.

235
Stromberg B, Carter YF
Also good Carter W-2 and Zenith 28 or 228 universal

261
Stromberg B, Zenith (from a GMC 270), Carter YF (from that company whose name is the same as the last name of a country singer from Tennessee )

Other possibilities (established companies) would be the Rochester B and the Holley 1904 (Personally, only recommend either of these on numbers-matching show vehicles which are not driven).

Jon.

Don, I bought a NOS factory replacement Zenith carb for my stock 1951 216 from Jon, aka carbking. It's been amazingly good. Easy to change since it was a original factory replacement carburetor and best of all, zero negatives. Highly recommend going to carbking's web site, getting the phone number and making a call.

Good Luck, Ron

Again, thanks for all the response posts. A few days ago I started experiencing symptoms like I was running out of gas. Motor just quits as if I were empty. After waiting a few minutes my wife brought me some gas but I could only put 3 gallons in the tank. I wasn’t out of gas. The motor started just fine and off I went.

This has happened two other times. I just installed a new gas line from the new fuel pump to a new filter that’s installed in front of the carb. When the truck stalls, the glass bowl filter is still full. Something is malfunctioning in the carb or it’s got blockage, sometimes. Ugh!

Don

Make sure the fuel pressure is not to high, had to add a fuel press regulator to get pressure down to about 2 lbs, carb was overflowing! lots of potential problems with vintage fuel systems, make sure tank, lines etc are clean and clear.

Trash floating in the tank and getting caught at the pickup tube? Same goes for the fuel filter.
And I just have to throw this in....how about the old vapor lock some have seen over the years??

or needle valve sticking?

Problem in the carburetor is my guess.

Vapor lock on a stovebolt six with normally-routed fuel lines is highly unlikely.

This could very well be the issue. The truck starts fine and idles perfectly. It runs fine and then just quits. Fierce pulling over I have to choke it to get it to start. But it starts and runs for about one block and does it again. And so one.

Don

I always have gas in the filter bowl so I doubt it’s blocking fuel at the tank. Doesn’t run even a little hot so I doubt it’s a vapor lock.

Don

Vapor lock is quite rare, especially in November.

Some possibilities would include:

(1) vacuum on tank (tank vent inoperable or missing).
(2) trash in tank stopping up sending unit
(3) broken or loose line fitting, allowing air to enter fuel line
(4) residue on carb float from evaporation of modern fuel causing float to stick in closed position.
(5) carburetor fuel valve stuck to fuel valve seat

And having fuel in the bowl does not mean it is under pressure. If there is a vacuum on the tank, the fuel cannot flow.

Jon.

1 is out. It’s there and open.
2 maybe. But the problem is like clockwork. Also, I don’t have to do anything except pull the choke and it starts. Zero rough running. Idle is really good and it never stalls. Happens at top speed or when driving down the road.
3 new fuel pump, lines, filter and carb. Less than 300 miles.
4 no residue in carb
5 maybe. But it’s brand new from rebuild kit.

Thx Don

Also possible, a starting to fail electronic distributor conversion???

Jon.

"New" does not always mean "good" where fuel pumps are concerned. Until you test it for volume, pressure, and vacuum you can't be sure it's working right. Pressure and vacuum should stay put for at least a few seconds after the engine is shut down- - - -that tests the integrity of the check valves. The pump should produce at least a pint of fuel into a catch container at idle speed in 30 seconds. Also be sure the flex line between the pump and the frame doesn't have a pinhole air leak.
Jerry

Only vent I know of for the fuel tank is the gas cap. I have seen the wrong gas cap sold and would not vent the tank and would create a vacuum on the tank and stall the vehicle.

The other vent in the fuel system is in the carb.

Maybe a crimp in the line restricting the flow, but my bet is a non-vented gas cap.

Just had something similar happen to me, turned out that a piece of something had gotten under the main jet. Looked like some rubber sealant or Teflon. It would idle fine, then when I was about a mile down the road It would quit. As soon as it quit I think the obstruction would drop back down out of the way. Then it would start right up. I was already having problems getting the carb to quit leaking, so I stumbled on the cure accidentally.

I installed a pressure regulator just before the carb. Set it on its lowest setting. Didn’t change anything. New carb going in tomorrow.

Don

That could very well be the problem. But I’m not putting anymore of my time into it. New carb going in tomorrow.

BTW what may look like a leaking carb quite possibly is the float out of adjustment. The float isn’t shutting the flow off before the gas level in the bowl reaches the gasket height. Or the float has a micro hole in it and is sinking. This would require a higher level of gas to shut it off.

Don

Whenever I have this type of problem, The first thing I try to do is pull a spark plug or 2 as soon as the engine dies and look for either bone dry or soaked with gas condition.
Bone dry will indicate fuel delivery issue upstream of the carburetor, or the float needle is nearly glued to the seat, greatly reducing fuel flow into the bowl.
Wet spark plugs would indicate a carburetor problem, causing a flooding condition.

Decided to gut the whole fuel system. Bought a new tank, lines, fuel pump, filter and carb.

Kind of fun bending the fuel lines and installing the new tank. Looking forward to not worrying about “what the problem could be now” anymore.

Thx Don

The wheelbarrow approach to a problem can work- - - -"Roll a wheelbarrow full of parts up to the job, and swap stuff until it's fixed!"- - - -but there's a downside. With every part that's changed, there's a possibility of introducing a problem that didn't exist before. The more parts, the greater the chances of error. "New" doesn't necessarily mean "good".
Jerry

Well the tank required a shoehorn to get it in place but everything went in as it should. Bent new gas lines and got rid of that “fixed” look. cinched the flared connections together and not a single drip The fuel pump was the biggest problem. It was newer but had too much pressure. Now with the correct size and well rebuilt carb it runs better than ever. With only a gallon of gas in the new tank. I drove to the nearest non eth pump and filled it up. I took the old tank and threw it away so there would be no chance of someone trying to make do with it like I did. IMO for the fuel system. This is the best approach. I got a lot of advice here and I’m 99% sure only one guy was correct on the problem. Yet I chased almost all the responses and wasted a lot of time.

Rebuilt carb-$200
Gas tank-$150
New petcock with flex hose-$40
Gas line-$7
Fuel filter-$38
Pease of mind- PRICELESS!

Thanks to everyone for their help
Don

Nicely done Don. Sometimes you just need to bite the bullet and throw a wheel barrow parts at a problem. Even if you happened to be wrong about the fuel delivery system, you certainly, once and for all, eliminated that issue as a part of the problem. All too often we find ourselves unknowingly dealing with multiple issues at the same time. That is the toughest diagnostic conundrum.
Carl

I agree with Carl.

Don, what is your guess, now, for the bad part?

Tim
I believe having a fuel pump that “fit” but was too big was my problem. I also think it could have damaged the float pin seal too.

Also the gas tank was original. It had quite a bit of gunk in the bottom and probably going to give me problems soon enough. It would have been a lot of work getting it cleaned out and I would never be confident it would be 100%.

Now the motor starts without choking even after sitting for a few days.

I was going to gut the fuel system in the beginning but it seemed to run okay and I was dealing with brakes and other items first. I’m sure I was dealing with more than one problem but if I replaced the fuel pump first I wouldn’t have gone through all of it for several weeks and just want to drive it around without worry.

Thx Don