6V vs 12V condenser

[PGBuick]

I did some searching on the forum as I troubleshoot a problem with my 59AB, but looking to more savvy flathead folks here to help me solve this issue.

First, everything is essentially new on this H&H built motor that I acquired. I am running 12v negative ground. All new wiring. All new fuel system including the tank. It came with a helmet style distributor with stock vacuum brake that appeared refurbished. Points looked good and gaps were good, about .016". It has a coil adaptor connected to a remote mounted 12v coil. I am using a ballast resistor to give me the correct coil resistance and primary voltage. The distributor came with a small can type condenser with a wire on it, like you'd see on later 50's/60's GM (and maybe Ford?) systems. It is connected to the distributor terminal on the coil adaptor.

Car has been running great, and it has about 50 miles of run time on it with no issues. Seemed as if the distributor had been set up very well based on how it has been running. I do have a timing tab but had not yet checked where it was set.

Today I warmed it up and drove about a mile, at which point she began to suddenly run very poorly. Idles rough and won't take throttle without breaking up severely. Essentially barely running under load and not idling great either.

Fuel pressure is about 3 psi. I recently added a spring type fuel regulator and gauge in the line between the pump and carb, and fuel to the carb seems adequate. Carb is a refurbed (or new repro?) Stromberg 97 with a brass check ball type inlet fitting.

The sudden bad running seems classic electrical to me. Points, condenser, coil? However, upon inspection and testing, they all seem fine. The fuel pressure regulator setup is all new since last driving, so I also need to suspect that as the primary cause, however, it appears to have plenty of fuel being delivered to the carb inlet and the gauge reads 3psi steady.

My questions today:
- are 6v and 12v condensers the same?
- Do I need to be running a stock type condenser like the Napa FA-49? Keep in mind the condenser/coil/points setup I described above has been running like a champ with no indication of problems until today. Condenser checks out OK with ohm meter.
- I will check the brass check ball on the carb inlet, which is very different from the typical needle and seat arrangement I've seen on prior carbs. I don't know if these ball type inlets are problematic or might somehow be causing issue with the new fuel pressure regulator arrangement at 3psi. If I open the bowl, where should the fuel level be at? Any feedback welcome.
- I'm not a fan of the helmet type distributor as it is a bit challenging to setup without special tools. Would a crab style make things easier for me to service? I've read here on many posts that the stock distributors are good, reliable devices, yet the helmet style seems hard to work on. Convince me to keep it, or upgrade to a better, more reliable distributor. I am the first to admit that I am very well versed in more modern 1960's era ignition systems, and the flathead stuff has been interesting to learn about, but remains a bit unfamiliar, thus, hard to troubleshoot.

Thanks for any feedback!

[tubman]

Condensers are not voltage sensitive and will also function well over a wide range of capacitances. However, current units can be shoddily made and bad out of the box (leakage and bad internal connections). Buy a couple of quality condensers at NAPA and try them both. Three bad ones in a row is pretty rare, although it has happened.

[HambBurglar]

Somewhat off topic, as a young man I worked in an auto parts store. As a prank, we would charge a loose condenser by pulling the coil wire off of the distributor of our propane powered fork lift and insert the wire end of the condenser into the coil wire. Holding the round base to ground on the engine and turning the engine over long enough to spark a couple times into the condenser put charge into it equivalent to being hit by a spark plug wire. If you only touched the round body you were ok but if you touched both the round body and the wire, you would complete the circuit and the the condenser would discharge. We shocked the crap out of many unsuspecting coworkers and at the time found it to be quite funny.

[Bored&Stroked]

You really can't checkout if a condenser is working with an Ohm meter. You have to have a special device that charges it and checks the flyback.

A properly setup crab distributor is FAR easier to work on than the ole' divers helmet style. It is functionally about the same as a more "modern" points style ignition. Unless I had TWO correctly setup diver's helmet distributors, I'd go to a crab style in a heartbeat.

[Mart]

Sometimes the rotor arm gets weak on the helmet distributors and allows the spark to short to the shaft the rotor sits on. A new rotor might help or pit some heat shrink on the shaft. This, like many rotor/cap problems normally shows when hot and "heals" when cold.
Does your car drive ok from cold and only have problems once warmed up? I have had similar problems with rotor and cap on crab type distributors too.

Mart.

[deuce_roadster]

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What Mart says is aggravated by using an extremely hot coil. Remember electricity goes to the easiest ground, sometimes that is the shaft the rotor is on in a "helmet" distributor. In my opinion, a street flathead doesn't need any high output spark at the plugs. Plug wires for radio suppression adds to this problem too. Did you eliminate the stock resistor when you added the external one? If not, your double resisted system will gain resistance as both warm up and get hot and the coil will have barely enough current to make sparks.

[PGBuick]

Update!
At my age, I should know to ALWAYS suspect the last thing I messed with. Just prior to this issue cropping up, I built a new fuel line between the pump and carb to add a regulator and gauge. Everything was clean, but not clean enough. Upon disassembly of the carb, I found some very small pieces of debris in the bowl and maybe under the power valve. Clean now, and running fine. I also set up a spare helmet distrib and condenser. Lesson learned. Even though it felt like an “ignition issue for sure”, it was fuel. I’m learning the flathead is pretty simple but has a personality all its own. Thanks for all the tips.

[Anteek29]

Originally Posted by PGBuick

Update!
I’m learning the flathead is pretty simple but has a personality all its own. Thanks for all the tips.

Like people, each vehicle has a personality of its own. After entering and getting seated in each one of my classics, I have to program my brain with the procedural checklist particular to that vehicle in order to start, shift and navigate correctly. I think you all know the drill as well