Jon G, that sounds like a good option, but I am going to be running a 261 shortly, and not sure if a Carter will provide sufficient air flow for it. I am tempted to experiment with Jerry's idea of the 258 AMC carb.
-Patrick 1953 Chevrolet 3100. 216/3 speed.Commercial Red.
Patrick, the 261 runs the same intake and exhaust manifolds as a 235 so swapping carbs might not produce a noticeable gain in performance RPM-wise. Finding one that's jetted for a similar cubic inch displacement engine would probably improve the low end and midrange performance, or at least provide a good starting point. The 261-specific Rochester B is a scarce item, and I'm sure it would have all the characteristic Rochester headaches as well. Jerry
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I'm just looking for a "best, most reliable" option to use. I have a Rochester B (not the 261-specific) that will be used for now.
This would be either a Stromberg or a Zenith. In addition to adjectives "best" and "most reliable", you can also add "most expensive".
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify If you truly believe "one size fits all" try walking a mile in your spouse's shoes! [image]http://www.thecarburetorshop.com/Avatar.jpg[/image]
Lots of good info. Live and learn I guess. I found a local shop that advertises that they work on Rochester B carbs. They discussed the warping concerns with me and said they know how to repair it. Hopefully I'm on the right track. I'm bummed the first carb that came with the truck is long gone.
Second question. I asked about a port on the side of the carb. He explained thay it was a vacuum like that attaches to the distributor. I told him one was never plugged in. I looked at a bunch of pics online and looked at my truck again. The mentioned line from the distributor runs to a port on the intake. If that is correct, what is done to the port on the carb?
The proper vacuum feed to the distributor vacuum advance is almost always taken off the carburetors "controlled" vacuum port. This vacuum port can usually be identified as being slightly below the throttle plate cross shaft. Basic operation:
1) At idle the throttle plate is nearly closed, cracked just enough to allow "some" air to pass through the venturi to mix with the low speed/idle port fuel mixture. There's very little vacuum present below the throttle plate so NO vacuum is passed to the distributor's vacuum advance. You don't need timing advanced at idle. 2) As the throttle is opened, vacuum is generated under the throttle plate which is then applied to the distributors vacuum advance which activates it (advances timing) 3) Vacuum will continue with increasing RPM until the throttle plate hits a certain degree of open when the vacuum under the plate ceases to be enough to operate the distributors vacuum advance. This is OK as the mechanical advance has taken over by then.
Vacuum advance is off at idle, begins to advance timing at low speeds to mid speed then drops away at higher RPM and/or acceleration.
The vacuum for your distributor should come off of the control port on the dist and not from the manifold as it probably provides vacuum at idle (not needed) and at higher RPM when the mechanical advance should have timing advance control.
Easy way to determine which is the control port is by placing your finger over the port, at idle there should be no vacuum (suction), open the throttle a little and you should feel vacuum (suction)..
FWIW, I have had good luck with replacing the Rochester B/BCs due to recurring leak/warpage issues with the Chevy-spec code 14-xx Stromberg carburetors (BXDV-3 or BXV-3s) on 235s, and using BXOV-2s on the 216s. The nice thing is they have leather accelerator pump seals, so will last better with ethanol (E10) fuel, to Jon G's earlier comments. The Stromberg's pop up regularly on eBay, sometimes well priced, and sometimes at ridiculous prices.
Many times, I've found NOS or old-rebuilt Stromberg carbs at very good prices, just takes some shopping and patience. It's getting much harder to find BXOV-2s that are good and affordable, especially if they are the later 1-5/32 venturi models. Earlier 1-3/32 venturi models are still fairly available.
I have a bit less experience with the older Carter OE carbs, but the W-1s seem pretty bullet proof. The Carter WEs seem viable as an alternative, and I've used some of the fairly common 730s replacement carbs with pretty good results.