I'm working on the Merc with a 312 and 3 speed automatic (P R N D L). The owner says he can outrun this car for the first 100 yds. We checked the timing, 6 BTDC. We checked the compression. Ranged from 125 to 150 about a 50/50 split, so not at the best. He uses leaded gas, not sure about the octane. We adjusted the single 4 bbl carb. This engine fires right up, runs smoothly, sounds great. Shift into gear and the torque converter engages solidly (bumps the car forward if the rpms are a little high). This car is stock, other than the air filter. The owner recalls from youth that these cars had more guts that what he's seeing.

So any suggestions on boosting power? 

He also mentioned that he only feels the car shift once. I know it's a 3 speed, but why only one shift (not sure this is related to the lack of power). Starting in 2nd? Not sure that's possible. Any linkages adjustments that might be off? Thanks.

What Year is the Merc? 55-56? Transmission is 3 Speed. Starts in 2nd unless You manually shift it to low and then shift it back to "D". Or floor the Gas to start off in 1st. These Engines have enough Torque to start off in 2nd in most Cases. Is the Carb an original "Teapot"? Or has someone installed a newer 4 BBL? The original Distributor will only work properly with the Original Carb. Is the Timing advancing as RPM increases?  The factory timing is very conservative.You can bump it up to 10-14 BTDC and see an improvement. Low Compression Engines can handle more Timing. The Distributor works only off Vacuum (Loadomatic) supplied by Carb. There is no Centrifugal Advance on these Distributors.  If the Car is lacking Power starting out there may be an Issue with Timing.

  

Thanks for the suggestion. It's a 1956 model 64 2 dr hardtop. When you say "teapot" style carb, what do you mean. The vacuum line is coming off a block on the back of the carb to the distributor.  We found a second vacuum line from the front of the carb that also was routed to the distributor, but is was plugged with a bolt and just laying there. We measured 18Hg of vacuum. I will verify that the timing advances on rpm increase.

One other note, the manual states 6 BTDC at 475 rpm. With the engine running at 475 rpm it sounds too high. We checked the timing with the vacuum line disconnected from the distributor and capped off.

Here is an example of a "teapot" carb or the Holley 4000...
https://www.hotrodreverend.com/post/rebuild-tips-tricks-for-the-holley-4000-carburetor

What oldcarmark is telling you is spot on concerning the 54-56 Ford and Mercury distributors. They are VACUUM advance ONLY and have no mechanical advance. By now you have discovered that the 56 version has a dual vacuum advance on the distributor. Both of these must be plumbed to the carburetor and getting the correct vacuum signal for the advance to function properly, no matter if this is a Holley 4000 or the WCFB carburetor. If I recall (and other fellas will chime in here) the inner most is for the signal near the spark control valve and the other for the rear of the carb...

A good thread to visit:
http://forums.y-blocksforever.com/Topic142177.aspx


Daniel Jessup

Loveland, Ohio

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

Does the Advance Unit work? The Diaphragms can rupture after Years of use. Attached Pictures may help. If You take the Cap off and manually turn the Breaker plate and hold your Finger over the inner vacuum outlet on Advance unit does it stay  advance or spring back when You release breaker Plate. If it springs back the Diaphgram is likely no good.

  

OK, I take it back, not stock, not a teapot carb. So that explains why there's a plugged vacuum line laying on the manifold near the distributor. The distributor is probably not original either. The vacuum connection on the distributor diaphram is of the push on rubber hose variety. Thanks for the links.

The wipers on this car are real slow, we measured 18hg on the line destined for the wiper motor and blocked off any side lines in case of leaks. Any idea what the proper amount of vacuum should be?

You have a timing light. Rev the engine and watch the timing mark on the engine. If it does not move your advance vacuum can is not working making your engine have next to no power.
To check either or both vacuum cans remove the distributor cap, put a length of hose on each line one at a time and suck on it. The plate containing the points should move.
The dual can is expensive to buy but since you have one it can be rebuilt for a lot less money. The Carter WCFB was available from one of the assembly plants and for most a more desirable carb that still needed the loadmatic distributor.
Most here have upgraded their carburetor and installed a 1957-1962 distributor. It was the first thing I did to mine. Good luck.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

The wiper Motor may be slow because it needs looking into. There is a diaphragm inside which can dry out. You may be able to get a little Transmission fluid into it through Vacuum Line for Lubrication. 18hg of vacuum is more than Sufficient for Operation. If You take Distributor Cap off are Springs Visible on top of Breaker Plate? Starting to sound like a mismatched Carb and Distributor Problem.

  

Definitely check the vacuum advance for function. It sounds like you have a later type carburetor and a one vacuum line distributor if that is correct the vacuum advance is suspect. Make sure the points are set right and not pitted. 
For the wiper motor if it is getting a strong vacuum signal it could be the internal leather paddle is not sealing. Sometime taking the feed hose off and pouring a small amount of transmission fluid in will help it reseal. They are not terrible to take apart and clean to add new grease if needed. Be very careful of the vacuum chamber gasket though it has to have a good seal to work. I finally went with a 12v electric unit and have no more problems.

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

All great advice.  As others have stated, the early distributor carburetor mismatch is a common problem with pre 57 YBlocks.  If you install a 57 or later distributor with centrifugal advance you will think you have a different engine.  These distributors are getting hard to find.  There are new replacements, but they are pricey.  There is a lot of information on this forum about auto parts store "rebuilt" distributors.   Spend some time reading through it and you will know what to look for.