Technical v12 Lincoln ignition problem

Here is what I have, 48 Lincoln V12 that turns over fine till I turn the ignition switch on, then it labors like the battery is dead, it stops on every cylinder then labors to the next cylinder and so on, but if I turn off the ignition switch while still holding the starter ****on it stops binding and turns over fine. This is what I have done so far, sent out 2 distributors for a rebuild (so I have a spare), plugs, wires, condensers, rebuilt starter, new 6-volt battery. The terminal plates terminals measure about .025 from the rotor terminals and when I pull a spark wire off the spark jumps about a 1/2" to the plug. I think the distributor is too far advanced, but the rebuilder said they were perfect, both distributors have the same results. The coil and terminal plates haven't been rebuilt yet. This is a long term project that has finally hit the streets, well when it starts it does. Is there anything I missed?

 

It sure sounds like the ignition is advanced too far. It would only need to be advanced by 5 degrees to much, before it pushes back against the ignition when cranking.
A low battery voltage, or a weak, wore out starter can cause the same problem.

 

Your distributor is not set correct

 

Adjust it to later spark and see what happens.
Depending on what method is used to adjust the ignition advance, it may not be possible to get it right without the engine running, as things move a bit differently at speed.

 

Sounds like to much Advance.
Sparkplugs firing BTDC
the fuel mixture to soon pushing back on pistons .

Can you start it like you would with
a Mag ,
Switch only to engage starter spinning before coil .
Spine the Engine for 2-5 sec while spinning Fast then flip power to coil
or remove Ground if Mag ignition.

Check the Battery drop,
Battery big enough
Amp & size , cable sizes Hot & Grounds
sizes, connection.
Check with Meter ,
Check dwell of points

 

The timing of the distributor is a bench adjustment similar to the v8 flathead

 

The advance is easy to check with the small tab/washer thing on the advance bolt, and the tick marks on the side. I’m not sure what the number is supposed to be for a V12, but I’m sure it’s in a book somewhere.

I’d think it also might be a ground problem. Check all your connections, and if you have any ancient wiring, be aware some of the corrosion or breaks could be covered by the insulation.

 

New battery, does it even when I put the battery charger on boost start, starter rebuilt by generator shop that knows what he is doing.

 

That was what I thought, rebuilder said both were rebuilt and timed on distributor machine and are perfect.

 

It was set up on a distributor machine, so I shouldn't have to adjust timing just the vacuum brake.

 

Well, dang it, man, if everything is " perfect" why are you here?

Ben

 

Yes, that is why I sent it out for rebuild. My 85 hp. in my 40 coupe was done by bubba years ago and you only have to touch the starter ****on and it is running.

 

Just saying
No matter New , set on Machine, rebuilt
You have a issues
So simple test / Diagnostics need to be performed

I can start my 12:1 engine with
Small Motorcycle battery , but it need to start on 1st try if not battery to low because of size & amps
Think of a battery as a gas tank

 

New build all new wiring, paint removed and dielectric grease on all connections. Everything has its own ground wire. The ground wire goes from the battery straight to the motor then to the frame and to the firewall.

 

Well, I think it is time to send the distributors to someone else to have them checked, who is the distributor guru now that Bubba isn't available any longer. I sent the first distributor out due to the badly pitted points needing replaced this all started when I got it back, I didn't move any of the adjustments he made when he rebuilt it, just mounted it on the car and the binding started. Then I found another distributor at a swap meet and called him an told him I was sending the first one back to check the adjustment and another one for a rebuild so I have a spare. When a I got them back he sent a note with them that said the first one as way off but is perfect now and the second needed parts that were missing (that I knew was missing when I sent it) and it is better than the first one.

Thanks for the help I'll update when I solve the problem.

 

What does it take to adjust timing at home? Meaning, does it really need to be sent out every time?

 

I've tried battery charger on 6 volt boost start, still the same turns over fast till I turn on ignition then it binds on every cylinder, keeping my finger on the starter ****on and turning off the ignition switch it rotates fast again no binding.

 

Did a little research, interesting that the two banks are not in sink with one another.

 

First, a disclaimer. I have never even SEEN a Lincoln V12. Let alone worked on one.
What you are describing is cl***ic "kick back" from ignition timing being set too fast. The distributor is firing when the piston is still too far from top dead center! It should be firing , I am guessing, about 4 degrees before TDC. Can this engine ignition timing be checked with a timing light like GM engines with Delco distributors?

Ben

 

On a Lincoln V-12 with dual distributor caps it seems like it might be easy enough to install the plug wires out of register, even on just one cap. Doing so would shift the timing either advanced or retarded depending on how you clocked the plug wires. Even if just one side of the distributor had too much advance it would probably be enough to buck against the starter when cranking.

 

^ Firing order wiring could be off. Double check that. The vacuum brake is the only means of fine tuning the timing on the car. The actual dist. timing is set with a strobe on a dist. machine. Sounds like the dist. has too much advance and needs to come out and set up on a machine to get it right.

 

This sounds like something out of the ordinary, if timing can be adjusted with the distributor off the engine. AFAIK it is usually adjusted by rotating the distributor (or something similar to that) once on the engine. There are plenty of things to adjust in a distributor too and some of that can only be done easily on a distributor machine, but basic timing usually isn't one of those things.

 

On early flatheads the distributor was bolted into place in a fixed position. The distributor housing could not be rotated to adjust initial timing. There were special tools and gauges used to set initial timing with the distributor on the bench, which was then bolted in to a fixed position on the engine. Some other methods were also used to adjust this initial timing point.

https://www.vanpeltsales.com/FH_web/flathead_engines_distr-timing.htm

I guess you could use a timing light to check the timing but any adjustments required removal of the distributor.

 

Advance is set by the small screw on the left side of the distributor.



This is a V8 but they look the same. Centered is the factory setting for advance. Or maybe one tick off. Mine is retarded a bit (adjusted the screw upwards) because I had pinging from too much compression. You can fiddle with yours to adjust it too. You might want to do this with the engine off since the fan is spinning so close by.

Anybody who has had the distributors apart will notice the cylinder numbers marked on the caps. If they are run to the wrong cylinder, it’s a definite duh moment.

 

If you take all plugs out
& get about 60 deg's of TDC
Hook a timing light or # 1 plug & ground , ignition on /coil power
& turn engine real slow by hand or cranking
look @
strobe or spark on plug
Should be able to see how much
Advance is b4 BTDC or ATDC is set now

 

This is kinda like physics to me, but how does the advanced ignition push back, exactly? If it isn't running or hardly even firing.

 

Well this is a "duh" moment for me, as I haven't really spent any hands-on time with Lincoln V-12s or flathead distributors. Obviously.

Does the adjustment you show adjust the actual static initial timing, or is that for the rate and amount of the vacuum advance? Either way, it doesn't look like it gives you much wiggle room.

 

For best performance you generally want the compressed air/fuel mixture in the combustion chamber to start burning slightly before the piston reaches top dead center. It's kind of hard to comprehend but it does take a few milli-seconds for the fuel to fully ignite. By lighting things off too soon (advanced timing) the maximum combustion pressure builds too soon. And instead of pushing the piston down after TDC and making some usable power, it tends to try to push the piston back down in its bore before it's reached TDC, attempting to make the engine run backwards. And putting some extra stress on the starter.

 

If you have too much spark advance in it at the moment you probably don't want it to start.
Pre-ignition (or "pinging") can damage things if it fires up.

From what I can find, it is a good idea to have the mechanical/vac advance and dwell set up on the distributor machine. You say this has been done. The only thing left is to set the base timing at the recommended setting, which appears to 2 degrees BTDC factory. Have you checked this, and if so what is it set at...???