Hard Starting Y-Block

Motorhead6

Senior Member
I have a restored '55 fairlane with all new original style wiring and new ignition switch and solenloid. There is no resister as it is 6 volt. I am anal about grounds and firm connections and in fact have rechecked for a loose connection several times. It is still 6 volt and has a heavy duty industrial type battery. The starter has been gone through by an old school professional twice and, hot or cold, spins the engine like a 12 volt system would. I have professionally made "O" guage welder lead battery cables.

Having said all of that, it starts immediately when cold whether it has sat for 4 hours or 2 weeks. However, as I drive it and it comes up to temperature, it is hard to start. The hotter it is, the longer I have to grind to get it started. As noted, it turns over fine but just takes a few seconds to start. I have replaced the coil; no improvement. I have reset the points using a dwell meter; no improvement. I have installed a new 435 CFM Holley that does not leak down; no improvement. I have rechecked the timing and verified the location of the timing mark on the harmonic balancer. As I said, when cold it starts immediately which sort of eliminates the carb.

Help!
 
I would first check the float level. Heat makes our newer fuels want to expand and flood the motor. Run the level to the lower of the adjustment. Scrapiron has a good suggestion, anyone who frequents this page sees a pattern of poor quality condensers in the past ten years. If you have a known good one, leave it. .
 
Had same problem with my 56 F100 292. Would fire right up when cold and once hot I would grind away on the starter for 5-6 seconds before starting. I changed from ethanol gas to non ethanol and the problem went away. What was happening was the carb would get very hot about 135-145 degrees, verified with a laser thermomenter, when I would shut off the motor the ethanol would start boiling in the bowl and overflow down the throats of the carb thus flooding the engine. You may have other issues but that's what solved my problem.
How is your compression when the motor is hot?
 
Thanks for the ideas. I will buy a new condenser and recheck the float levels. It is a pretty fresh 312 and I have not done a recent Compression test. Runs great once started. I will also check the compression.
 
If the float levels check out O.K., and the condenser is good, I'd be putting an insulating spacer between the intake and carb to limit the heat transfer to the carb. I'm assuming that you are using a later 4150 or 4160 Holley, and have changed to the '57-up distributor to match it. I went through this identical problem a few years ago and it was due to reproduction battery cables that were 3/4s insulation and 1/4 wire although they "looked" heavy, but you've got that covered already. Good luck : Bruce
 
If you have the original air cleaner, perhaps it is trapping evaporated fuel that has to be cleared before the mixture is lean enough to fire. Try removing the air cleaner and starting it next time you get it hot. John
 
is the car hard to start as soon as you shut it off or after it has sat for a few minutes.if its hard to start the minute you shut it of its not the carb.
 
3 things will cause hard starting when engine is hot, bad coil, weak condensor, flooding carb from engine heat boiling gas into the intake manifold, when you shut down the engine pull the air cleaner and look down carb to see if any fuel is draining into the manifold, aluminum manifolds cause fuel boiling more than cast iron, add a 1" phenolic block under carb, put your hand on the coil, if its to hot to leave your hand on it chances are its bad, when turning over engine when hot pull coil wire and see if you have a good blue spark
 
Float levels were right on but I lowered the primary 1/2 turn and the secondary a full turn. However, the secondaries were leaking onto the butterfly. This allowed the car to start right up when cold as the primaries were full. When warm, the secondary leak caused flooding just as some of you suspected. Replaced the gaskets and all seems well now.

Thanks for the advice from all. Ford Barners are the greatest.
 
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