what carb to use?

S

steve fritz

Well-known member
I have a 54 Mercury with rebuilt 256 original Y-Block. The car runs just OK with the stock Holley 4bbl as original. I have had trouble with the dependability of this carb. Hard starting when warm , flooding out , and just real sluggish performance.
I want to upgrade the carb and also change the distributor to 57 and newer style with vacuum/mechanical advance, eliminating the original load-o-matic distributor. I have read much on this subject and also talked to Bubba in Indianapolis. He is going to do a but change on my distributor and convert the bottom end of a 57 distributor to fit my oil pump drive and cam gear. So that part will be upgraded when I get the modifyied distributor back from him.

My question now is what carburetor should I switch to?? I am thinking about using a Carter WCFB that Mercury used starting in 55/56. This carb has the same bolt pattern as my 54 intake manifold, so that would be a real plus, not having to use any carb to intake manifold adapter plates. The later model Holley , Edelbrock and even Autolite 4100 all have a broader bolt pattern and would require me to use an adapter to fit the stock intake manifold. My question is this on the Carter WCFB......is it compatible with the later vac/mechanical distributor advance system ?? Am I gaining by using this carb?
I must add that I am not interested in super high performance or racing applications. I just want to wake up this y-block and get some dependable performance. I have had bad experiences with the tea pot, like flooding out and poor acceleration.
Would appreciate hearing from anybody that has switched out these 54 Mercs or even the 54 Ford 239 ?? These are smaller ported heads that Ford used before 55/56/57 models, when they came out with the 292 and 312 engines, which had bigger heads.
Thanks for any comments or suggestions.
Steve
 
I would guess just upgrading the ignition you will see a difference. Just a guess. Maybe start there. What cfm is the holley you have now?
 
The Hollet teapot can be troublesome but set up properly are a good carby. If the Carter you buy will bolt straight on it would be a good replacement. The later Holley with a spacer will work well also. The adaptors are available from Summit and others.
Personally I would go with an adaptor and put a 4160 Holley 465 cfm carb on the engine. You can get a 390 cfm carb but they are lot more expensive than the 465.
You can be sure with these carbs that they will work correctly with the later distributor.
Regards
 
The older Holley and the Load-o-matic where designed to work together. The newer distributor will not work properly with the teapot because the vacuum signal on the carb is taken in the wrong place.

A WCFB off of a '55/56 Mercury would be the same because '55/56 still had Load-o-matic distributors. The WCFB was used on Buicks and others but I'm not sure how their vacuum port are set up.

I would suggest one of the smaller later model carbs (be it Edelbrock or Holley) as the carb and '57 up distributor would work well together.
 
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You can drill and tap a 1/4" pipe tap hole in the base of the teapot to provide vacuum for the later distributor. Then block off the original vacuum port. This is a good option if you have a nicely rebuilt teapot carb. I tried to locate an early WCFB with the small bolt pattern. Going to swap meets and sources such as e-Bay and Craig's List proved astronomically expensive for a rebuildable core to my thin budget. Also, most of the stuff available should just be pitched.

The teapot is a perfect choice in that it works very well with the Y-Block performance wise, but also looks right. They are readily available and if you get a kit from Daytona Carburetor,(I paid about $90.00) it is resistant to corrosion by the new fuels that we are forced to use. Just for self-assurance, I also use Sta-Bil. The leak down between runs is most likely a leaky fuel enrichment valve that sits on the floor of the float bowl. A new one will like fix the problem. It has a very weak spring so that the vacuum signal can open this valve and is thus subject to leakage.

By the way, I am way happier with the performance out of the teapot than I was with the Holley 600 CFM.

Using the later carbs with an adapter is a viable choice provided you stay below about 390 CFM. However, it looks a little peculiar on that motor. You could also go for a later manifod with the larger bolt pattern. There is supposedly a little mismatch in runner alignment, but you can fix that with a die grinder if you're handy. The down side is that this route requires a bit of an investment.

We all know what they say about opinions, and I guess this one is worth just about what you paid for it. :-)
 
Motorhead6 said:
You can drill and tap a 1/4" pipe tap hole in the base of the teapot to provide vacuum for the later distributor. Then block off the original vacuum port. This is a good option if you have a nicely rebuilt teapot carb.
Click to expand...

You need ported vacuum not manifold vacuum. The hole will need to be above the primary throttle plates.

Motorhead6 said:
You could also go for a later manifod with the larger bolt pattern. There is supposedly a little mismatch in runner alignment, but you can fix that with a die grinder if you're handy.
Click to expand...

More than a miss match of port runners, you may have a vacuum leak due to overlap. If you go this route check your gasket alignment closely.
 
To use the later bigger manifold you will need to change the heads as well. The manifold will not match the ports of the little heads. Been there done that.
Ted Eaton the yblocks forever site has a fix for the teapot to provide a ported vacuum signal for the later distributor. It does involve drilling and plugging the carb base. The small base Carters are designed to work with the load-a-matic distributor also and would need modification if possible.
With your engine you are limited in choices. Modify the teapot or use an adaptor with a later carb.
 
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