'51 Fleetwood 60 Special - Carburetors used

[6262]

Hello,

I am asking in behalf of a friend. He has huge problems with his '51 Fleetwood 60 Special. The car runs well for days. But it starts to stutter and churn to the point that it is barely driveable frequently. He is a very experienced and able mechanic (I often rely on him with the best of results) but now runs out of ideas what to do.

He guesses the reason is the Rochester carburetor which he has rebuilt several times without solving the problem.

He wants to replace it with another carburetor used in that MY.

So, my question is: Which other carburetors were used by Cadillac in '51? Was there a Carter like in later years?

Can they be exchanged without changing the manifold, do they need a certain special base?

Thanks!

[Bobby B]

If it's the original carb, why not have it rebuilt professionally by someone who does these carbs for a living and knows all the tricks? 
                                                                                                                                                                          Bobby

[m-mman]

He guesses the reason is the Rochester carburetor which he has rebuilt several times without solving the problem.

Einstein defined insanity as doing the same thing over and over and expecting different results. 

May I suggest that perhaps the carb is not the problem? 

We know nothing about this car but the symptoms listed all suggest OTHER problems in the fuel system.. . .

A COMPLETE Fuel system evaluation and diagnosis is in this thread.
http://forums.cadillaclasalleclub.org/index.php?topic=146381.0

[Jeff Rosansky CLC #28373]

Look at the ignition condensor. I chased a fuel problem for days until I tried a different condensor and that was the problem.
Jeff

[35-709]

Yes, I was going to suggest the coil but the condenser would be just as suspect.

[Lexi]

My thought as well, check ignition. Same symptoms with mine and turned out to be burnt points. Clay/Lexi

[6262]

Thanks for the quick replies. Gentleman, all your excellent suggestions have been already tried. The guy is a professional, who solved almost any problem on vintage Cadillacs and other American cars of my friends yet, including rebuilding my Hydramatic, cruise control, Radio and uncounted fuel and ignition systems and carburetors.
It is the first time he gets stuck.

So, there are not many options left. Is there another carburetor used by the factory in '51?

[Brad Ipsen CLC #737]

The Carter carb for 51 is Model 845S but it is not without its problems.  I think the Rochester is known to be better but John Washburn is the expert on these.

[6262]

Thanks, Brad. For '62 it is my impression that most people prefer the Carter over the Rochester.

I think it should be tried after everything else failed. Do you know if the Carter bolts right in?

[Brad Ipsen CLC #737]

There is only one intake manifold from 50 to 51 so should bolt up.  49 is the same except in 50-51 the exhaust gases go directly into the base of the carb for heat.

[6262]

Brad, thanks a lot!

[Caddy Wizard]

The 51 Fleetwood should have a 2bbl Carter 845 carb, which is an outstanding carb, in my experience and opinion.  I have had 5 1949-51 Cads with Carter 2bbls and have rebuilt quite a few of them.  These are great performing carbs and are not prone to issues.

I would suspect fuel pump (starving the carb of  fuel) or ignition problems.

I'll post a picture of a 51 carb...

[Caddy Wizard]

Here is a 1950 carb...

[Caddy Wizard]

I think that this one was either a 50 or a 51 that I did...