Sparking issues - 1946 Continental V12

[Uriel]

Hi Everyone,

 

This website is a great resource and let me start by thanking everyone who is maintaining the community for those beautiful (and finicky) machines!

I apologies in advance if I don't use the right vocabulary, I'm new to classic cars, and I'm also not a native English speaker, so I'll be as descriptive as I can.

 

I recently bought a 1946 Continental with its original 292 V12 , rebuilt some years ago but hardly driven (the past owner, I was told, passed away shortly after. the rebuild..). It was running really weak and could hardly move. We started troubleshooting with a friend who used to be a mechanic back in the 70s and 80s, and although we ruled out compression issues (it is within specs in all 12 cylinders), we noted that it only sparked "good" in 6 of the cylinders. The odd things is that it's got an issue on both sides:

- On the passenger side, only cylinder 10 sparks worth something (4th from front), some cylinders have a very weak spark, some none apparently; and

- On the driver side, Cylinder 11(6th from front) does not, while the 5 others spark just fine.

 

The car could run, but it dies out pretty quickly, which we initially blamed on a fuel leak off the carburetor that may (or may not) cause the engine to stall. My friend is dubious about blaming the carburetor for old cars' problems; in his experience, compression and spark should be investigated and fixed  first.

 

The plan is now to take the distributors off and take a closer look. Thank you Pete O. for the distributor exploded view, and CrazyCars for your step by technique to remove the distributor. Those will sure prove useful.

So far, we lifted the distributor cap and some of the spark plug wires' connections are really loose, they literally slid out when we removed the cap, while some were snug, and that was on the side of the engine that is mostly firing correctly (driver side). We had some troubles fitting the wires back in the plate/terminal because of the location of the distributor so we decided to leave it until we had more time to take the whole thing off.

 

It's currently pretty cold, which limits how much we can endure messing with a cold engine in an unheated garage, but I was wondering if anyone ran into a similar issue, and if they had a suggestion for a fix. I look forward to your suggestions.

In advance thank you,

 

- U.

[Uriel]

PS: after reading more on the topic, I might have messed up and damaged my coil today while trying: I noticed that I left the key in the ignition (in the position ready to push the starter button), and I read that this can damage the coil. With the distributor off, we will test the coil as well. Should we want to do that, how should we proceed?

 

Thank you,

 

- Uriel

[abelincoln]

Uriel:

I also think a good place to start is the distributor.  When you take it off, you'll notice what a mechanical marvel it is.  There are two sets of points, each fires plugs on both sides of the engine.  look for broken springs on points, or frozen points.  A way to test is to measure voltage at the points at the back of the coil, distributor assembly.  Should be 2.5-3 volts each while running. (Watch out for the fan!)  If the distributor is removed, note that one end of the tang is slightly larger, corresponding to the slot in the camshaft.  It is possible to install backwards, don't ask me how I know. 

If you find the need to replace parts, might find someone with an old distributor machine, or send out.  I've had good luck with Philbin Manufacture AKA flathead doctor in Portland.  I suspect the coil is OK, but they can be rebuilt or replaced with two standard coils.  Plug wires might also be bad after a long time sitting.

Abe

[19tom40]

I believe one side of your coil is bad or the condenser on one side is bad. Here is a link to a wiring diagram for your car.

 

http://www.boos-herrel.com/sitebuildercontent/sitebuilderfiles/download4678.pdf

 

As  you can see, wires from the right cap cross over to the left side and visa-versa. you can have your coil rebuilt by Skip Haney in Florida.

 

http://www.fordcollector.com/coils.htm

 

I use a SnapOn coil  tester to test the coils. Use power from the ignition resister to power the coil while testing, a full 6 volts will damage a good coil during the heat test.

[Uriel]

AbeLincoln and 19Tom40,

 

A lot has happened over the past 2 weeks but hardly anything with the car proper unfortunately... Work keeps me quite busy.

 

In any case, I have gotten very good opinions, yours, and even that of 2 well known folks in the community:

- Skip Hanley (who rebuilds the coils and water pumps for those Flathead V12 Lincolns and many flathead V8 [Num: 941 637 6698]) and

- Jerry Richman (who actually rebuilds those Flathead V12 distributors and carburetors [num: 774 218 1200]).

Both were extremely knowledgeable, and so eager to help; this community is just great!

 

Skip is pretty sure it's not a coil because I have sparks on both sides and on more than 3 cylinder on one side (driver side fires in 5 cylinders). He said that, as you pointed it out, each coils fires 6 cylinders, 3 consecutive ones on each side and, and I would not get as many cylinders on one side and so little on the other if it was a coil.

 

Jerry was awesome and asked me right away: "Tell me the truth: did you mess with the distributor? I have seen this twice in my life. Each time the guys hooked up the spark plug wires to the wrong spot on the distributor."

And I think he is correct. It makes sense and I think that I will have to check each of my side to make sure each spark plug cable goes to the correct spark plug. This theory is backed up by my mechanic friend who came up on his own to the same conclusion.

While I check the wires, I'll checks if the distributor is indeed correctly installed as well. Sadly, I won't have time to prove the theories right or wrong until mid-February (I need to go back to the old world to show my parents their first grand-child and we leave Saturday). 

 

If it's not that, Jerry advises to have the coils, distributors, and condensers, and rebuilt (his and Skip's prices are fabulous by the way; but I know it's a labor of love, not a business, that they maintain). Jerry by the way has a new type of condenser he uses, which I think he said he developed himself. That could be an option is the condenser is dead.How would I know if the condenser rather than the coil was dead? Only a condenser tool would be able to tell me? Or symptoms would be different?

I'll look up the flathead doctor in Portland. The only other flathead shop I know is somewhere my wife's relatives live near flathead lake I think, in Montana and it's a way's away from Moscow, ID where we live. Portland might actually be closer.

 

Thank you again for your pointers, and I will keep you all updated as soon as I get a chance!

More in February ! Best !

[19tom40]

 A bad condenser would show up as weak spark at the plugs fed by it's side of the distributor.