Replacement carb c2

[John P.]

Hello folks, Ive been all around the block with the Holley 2818 on my 1965 C2 327-350. Its been rebuilt by well known rebuilder-better but no
cigar mediocre performance. other tuning has been done. By the numbers I believe this is a service replacement carb from many years back.

I am ready to change out to a functional driver carb which hopefully is a simple bolton. Archives makes several suggestions, Holley tech line nonresponsive,

Any suggestions for a NEW carb to make daily driving more pleasurable?

[Duke W.]

Re: Replacement carb c2

Carburetors are pretty simple devices. If what you have is an OE service replacement the first thing to do is to get it configured as originally assembled and then go from there. What does "mediocre performance" mean - no power or something else?

If you give us some details on what the "issues" are and what work has been done maybe we can help out, and maybe it's not the carburetor.

Duke

[John P.]

Re: Replacement carb c2

Carburetors are pretty simple devices. If what you have is an OE service replacement the first thing to do is to get it configured as originally assembled and then go from there. What does "mediocre performance" mean - no power or something else?

If you give us some details on what the "issues" are and what work has been done maybe we can help out, and maybe it's not the carburetor.

Duke

On startup lots of sputtering. Have tried to set choke as per service manual, checked for power to the electric choke, adjusted it to 1- where the specs call for that. timing set 10-12 btdc, new plugs points dwell etc per specs, vacuum can as you recommended in the past. Interestingly the idle seems to vary as I drive from 500 to 800 rpm-this seems inconsistent in no real pattern. I always run 93 octane, have notice no pinging or dieseling. Mixture set as per service manual a few months back though not lately. Floats at recommend height. Fuel pump changed by me 1 year or so ago.

On startup my habit is to give full pedal-wont start otherwise unless engine is hot. Battery voltage fine on gauge doesn't seem to struggle to turn over. Fuel is not old-Seafoam added to tank. Fuel filter changed by me to filter recommended as replacement by Paragon I believe.

Hmm what else?

At WOT seems to run decently no power surges or loss on the highway. For some reason the carb linkage seemed to bind a bit but not obviously bent.

[Michael W.]

Re: Replacement carb c2

On startup my habit is to give full pedal-wont start otherwise unless engine is hot.

That's not the standard or appropriate start procedure. Engine should start with foot off pedal. The gas pedal should be touched only to set the choke and give an initial squirt of fuel. Keeping your foot on the pedal partially overrides the choke.

-Seafoam added to tank.

Please, no. Seafoam is great for it's intended purpose (unclogging carbs of WWII vintage 2 stroke outboards) but has no place in the gas tank of a car.

[John P.]

Re: Replacement carb c2

I have often thought to myself "well you are defeating the choke" with a full pedal on startup-but feathering the throttle seems to be the only consistent way to start the car when it is cold. I have had the car for 12 years or more-always has been the case

[Michael W.]

Re: Replacement carb c2

This infers that the choke or pull off mechanism is not working properly.

[John P.]

Re: Replacement carb c2

This infers that the choke or pull off mechanism is not working properly.

That has been my general thought though I used the measurements per manual for the flapper. seems in the past even changed out electric choke unit and verified current to it. Rebuilder says working fine .

So this is why a 300 dollar new choke to replace a non original is appealing if function will improve. In fact I would pay twice that.

[Don W.]

Re: Replacement carb c2

You may want to look at these 2 sources for tuning and trouble shooting guidance...Don

http://www.corvette-restoration.com/resources/technical_papers/Holley_Carb_Tuning.pdf

http://www.corvette-restoration.com/resources/how_to_articles.htm

[Joe L.]

Re: Replacement carb c2

...even changed out electric choke unit and verified current to it...

John------


So, this carb has been converted to electric choke?

[John P.]

Re: Replacement carb c2

The carb is a service replacement and I believe numbers on it suggest about 1970 or so. Came to me with electric choke Carb is List 2818 but replacement

[Gerard F.]

Re: Replacement carb c2

John,

Just a thought. Check the link between the primary and secondary throttle, so that at idle the secondary throttle is not flapping around.
Had this problem on my 3810 where it was hard to start and idle down. Flooded out so bad at a shopping center, I had to wire the secondary throttle to the carb stud to get home.

This may not be your problem but worth checking.

Also check your vacuum at idle and all the vacuum tubes for leaks, especially the tube from the carb to the vacuum advance. I had this problem too.

[Joe L.]

Re: Replacement carb c2

The carb is a service replacement and I believe numbers on it suggest about 1970 or so. Came to me with electric choke Carb is List 2818 but replacement

John------


I think it must be converted to electric choke. A SERVICE carb of Holley 2818 should have had the original style hot air choke.

In my experience, some carburetor cores become so degraded or abused over time that they cannot be satisfactorily rebuilt, no matter what is done to them. The part you see can be restored as-new; the part you cannot see is the problem.

If your primary interest is in having a good running vehicle and not exact originality (as your carb is not original anyway now with an electric choke), I'd buy a NEW Holley replacement carburetor and be done with it. Something like an O-80450 will have an appearance similar to original and it will be NEW, through-and-through. Nothing makes a car run like a NEW carburetor.

[Gerard F.]

Re: Replacement carb c2

Joe,

Don't like to disagree, but I think the original 2818 in 65 had an electric choke.

[Joe L.]

Re: Replacement carb c2

Joe,

Don't like to disagree, but I think the original 2818 in 65 had an electric choke.

Jerry------


It APPEARED like an electric choke but it was a hot air choke. There was a hot air tube that ran from a fitting on the lower left of the choke housing to the right side exhaust manifold. I don't know of any 1960's Chevrolet that used an electric choke. In fact, I don't think they were even invented until the 70's as part of emissions control strategies or otherwise.

By the way, these carbs with the hot air choke can often be converted to electric choke rather easily. However, 1966+ carbs with divorced choke present a much more daunting problem if one wishes to convert to an electric choke. I've been "down this road".

[Gerard F.]

Re: Replacement carb c2

Sorry Joe. I learn something new every day.