Here are some of the flow numbers on the holley 56 thru 58 ford carbs. !956 teapot 370 cfs, 56 lincoln teapot 390 cfms, 57 ford list 1273s 400 cfms 1958 ford 1551s approx 550 cfms being put on 332s and 352s. I personaly like how the 1958 carbs do on a little more than stock y being some increased air flow and better cams. The 57 and 58s are the 4150 design. These are some of the numbers I got from holley and Pony carbs. The 600s do seem to be a little big especially on a stock engine.

-Gary Burnette-

You're right in that the early setups are capable of very good fuel economy.  Those original setups with the Load-O-Matic distributor in place are analagous to the speed density system Ford used for fuel injection control in the late Eighties before going to mass air.  If any changes were made to the engine (ie. camshaft change) that affected the vacuum signal, then the engine just simply did not run right; Load-O-Matic and speed density systems are both similar in this regard.  The late model carb and distributor setup is similar to the ‘mass air’ change and simply makes any modifications performed to the engine either transparent or easily adjusted for in regards to the tuneup.

 

As a general rule, the Y’s like a lot of ignition advance for the best fuel economy.

Lorena, Texas (South of Waco)

Hello Ted,Thats very interesting info.My 292 is completely stock with a Fordo.Initial advance is supposed to be 6 BTC.How far do you suggest I can advance that without creating a problem?Thanks Mark

  

Mark,



Unless you have a new dampner, and your timing pointer has been checked for TDC, the #s are meaningless.



Ignition timing by ear might be complicated with auto trans, as flooring it at low speed in high gear (to listen for pinging) would cause a downshift? (not my field of expertise)



If no audible ping on acceleration, then the other sign of too much initial advance with '55 Loadomatic is rough-running at low speed cruise. Not sure about the '56 double-diaphragm set-up.










6 VOLTS/POS. GRD. NW INDIANA

Dan,

         Only on the ThunderBirds. The car damper has the marks on the part of the damper that's not rubber mounted. Doesn't change.

   Larger carbs are not intrinsically bad for mileage. There were several different versions of the Holley 600, with varying primary sizes. If you pick out a Carb with small primaries you will be able to generate respectable mileage numbers. The Secondaries will not operate unless the throttle is floored and manifold vacuum rises to a point that demands more airflow. They don't operate very often on the street. 

     Probably the biggest issue with the loadamatic is that nobody understands them anymore, and most of them no longer function as they were intended. Also most of us have issues with the Teapots and todays gas. 

Frank/Rebop

Bristol, In ( by Elkhart) 

Frank:

Not to belabor a point, but you have the damper info posted backwards.  The passenger car marks are on the rubber mounted damper ring, the T-Bird marks are on the fixed, non-movable part of the pulley.  Don't want everyone to assume their passenger damper can't slip.

John in Selma, IN

John - "The Hoosier Hurricane"

As Daniel mentions, the damper timing marks needs to be correct.  But with that checking out, then the condition of the engine has much to do with how much more initial advance the older Load-O-Matics can handle.  Simply said, the more worn the engine, the more initial advance that can be tolerated without detonation.  This has to do with the vacuum signal being reduced as the engine wears and the advancing of the timing simply compensating for this.  I visualize as much as 12° intial on a well worn engine where the vacuum signal is greatly reduced.  If the timing chain is stretched, then the vacuum signal is also reduced which in turn would allow more igntion timing.  Experimentation is the best solution  but I’ve found that the factory settings typically give the best results on engines that are in good condition.

Lorena, Texas (South of Waco)

John, Whoops, well you said I was a little backwards!

Frank/Rebop

Bristol, In ( by Elkhart) 

well I am going through all of this too. I wandered back and forth between a Holly and a Edelbrock carb. I have almost decided on an Edelbrock 500 cfm carb. I got a manifold off of ebay with the big bolt pattern. I also got a 57 up distributor and just ordered a Mallory electronic conversion kit and a Mallory coil from Summit Racing. Now all I have to do is wait for all of this stuff and decide on a carb.

Doing Fords for 45 years. '56 Customline Victoria

E.J. in Havana FL

I finally ended up with a stock 9425-B manifold and a "new" factory rebuilt 525 Road Demon Jr. that I got off an e-bay store. Electric choke. $263.00 with shipping....

Installed a maodified 1/2" phenolic spacer to funnel the bigger carb throats into the smaller bores of the Holley base manifold.

The 312 seems to like it and the only changes I've had to make are installing a set of steel needle and seat assemblies (.130) - and a stiffer vacuum secondary spring (the Holley black one). 

I believe she will make a good bit more top-end power if I take my spare manifold to the machine shop and (1) have the carb deck milled flat and (2) slot the two fore/aft throttle bores together side for side (so its like the Blue Thunder manifold). Then use a larger phenolic spacer that matches the Demon throttle diameters.

 
 Steve Metzger       Tucson, Arizona