Flathead Electronic Ignition Lessons Learned

I thought since I’ve pulled most of my gray hair out. I’d at least share what I’ve learned and maybe save alittle frustration with someone who may be experiencing these problems now and in the future.
I initially fired the 59ba with triple Stromberg’s and the original distributor converted to 12 volts last April.
The engine had a fair amount of torque but during full acceleration the carbs would cut out and/or the engine would misfire.
I played around with it most of the summer adjusting this or that trying to get it to smooth out during high torque.
The past month it progressively began to get much worse and was loosing power even during minor acceleration.

I decided to rebuild the carbs and asked our own ****ster to rebuild them for me. He has spent more time looking at these old carbs than I have my own wife. Very meticulous and knows his ****.
I first met him after buying a set of Holley 94’s setting on a Super dual intake on eBay. He spent many days helping me get that setup running correctly on my 21 bolt flatty after installing it on the original 37 engine. His patience was/is amazing and he taught me a lot over the years.

I closed off the center carb on my triple setup figuring the engine may smooth out and as most know these engines don’t need 3 carbs. There was little or no improvement on my high torque issues. So instead of messing around with the fuel system, I decided to make sure I had a good ignition system and then go to the carbs later.

I bought a front mounted electronic MSD distributor to replace the original. Although this thing is more expensive than any other, my reading of comparable distributors did not find anyone who had problems with the MSD’s once they worked the bugs out. I installed new plugs and spiral cored Taylor wires on this too.
After installation of the dizzy, I was advised to keep the total advance around 21 to 22 degrees. Msd advised me the initial springs and bushings installed on these distributors is a good point to start and most need no changes. The initial advance was adjusted by installing a vacuum gauge and advancing the timing until it’s at its max and backing it off ½ -1 lb vacuum pressure.
The engine fired right off, sounding very good and angrier than ever.

I found the engine to have even more torque than ever but...
The problem was….. the same exact misfire was still evident when tramping on the gas hard.
I decided at this point to take a look at the fuel system. And throw on a fuel pressure gage to see what was happening there.
I found the fuel pressure to be a little high so I cut down my fuel regulator for the electric pump to 1-1/2 lbs.
No change with this problem.

I advanced the distributor some thinking maybe since the engine was a *****y one that maybe I wasn’t getting enough advance and it was cutting out too early. I never did hear any pinging on this engine the whole time I was advancing it either. No change…The misfire was still there
By this time…about a week and half of screwing around I was about to give up. . I went over every ground and traced the ignition box loom through the frame to make sure I wasn’t get interference from another circuit...
Most of us thought it sounded like an electrical cutout but the fact that it did the same exact thing before this dizzy change had us in circles. Why would two totally different animals create the same symptom??

So off I go into fuel system checking never land….
I check the new plugs and found them to have considerable carbon on them telling me that I wasn’t running lean.
I again installed the fuel pressure gage into the center carb fuel line connection and took it out for a drive with the gage hanging inside the cab. I was thinking maybe the cheap *** fuel pump was cutting out during operation and not giving me consistent pressure. I hit the throttle hard and watch the gage stay exactly around 1-1/2 pounds but the engine cutout still was there.
Well that pretty much sewed up the fuel problem questions and off I go back into the ignition investigation.

I was getting to the point were I was going to break down and try changes with the distributor advance springs and bushings.
With absolutely no room in between the engine and electric fan at the radiator. I wasn’t looking forward to removing the radiator and to just go back and forth on a trial and error method of max advance and advance curve changes.
I talked to a few people experienced with electronic ignitions on these flatheads and got a lot of good advice in the proper methods of elimination.
Mr42, here on the Hamb, brought up the fact that although it was just a shot in the dark but it may be that the cam was installed a cog off.

Last try!
Before getting into anything serious, I decided to drive the truck over to an old fella who knows flatheads and is very good at investigating ignition/fuel problems. I never made it over to see him…….The truck died along the road after three miles with no power what so ever. I asked Youngbuck here on the Hamb to come save me J so we hooked up a fresh battery with jumper cables and used this power to get me back.

I found that my second Napa regulator took a ****. The first one was on the road last month with the other car.
I got to thinking…. Dangerous.
I wondered if this regulator was acting up all along giving me just enough power to charge the battery but not enough to properly power the Msd during high torque……
I check the generator by motoring it and found the regulator wasn’t working.
Sure enough…after installing the new regulator, the cutout issue was about 75% gone.
I’m thinking after burning off the carbon in the engine from misfires it may just smooth out all together without making any advance curve changes at all.
Thanks so much to all who have helped me get through this. I really appreciate it.
If there’s one thing I’ve learned from all this … to never make more than one change to any of the systems at a time.
Especially when you are not sure whether its fuel or ignition related. It’s so easy to take for granted things are working correctly until you find out that just may be a bad ***umption.
Please jump in here if you have experiences to add or advise to give.
PJ

 

Let's hope all those little demons are gone. Sorry I was unavailable to "scoop" you up off the road. I'm ready for another ride!

 

Congrats on finding the issue!

Too many damned things to check when your head starts creating solutions. Been there too many times! Glad you figured it out and thanks for the heads up.

Mike

 

Good systematic work!
Another issue: About changing one thing at a time.
With many mods, you HAVE to do them all at once when you build the engine. There's no reasonable way to do bore, stroke, and cam choice separately, for instance.
Externals are something different, though...I believe that a new flathead should be run in and tuned on a single stock carb and manifold--you can't reasonably flog the tuning needs of multiple carbs if you don't know rest of engine is right OR know how engine pulls the car.
Aftermarket ignitions are another can of worms that may or may not need considerable work. Ideal here too would be to run it in with a stock 21A, preferably one borrowed from someone's running car. Good points and functioning factory curve are pretty easy to verify as good to go, and swapping in most installations is quick and easy once you know basic engine is running well AND what it feels like when it's happy.

 

We had the very same problem with are HA/GR flathead engine you are having. With out going into hours of explantion, we unhooked the excellerator pump rods and that cured the problem. No one can explain why but it worked.

 

Yes,
Bruce thats a very good tip with the single carb and manifold change. I didnt go that route... just because i'm hardheaded.
That would have eliminated alot of questions right of fthe bat during the process.
Another important thing I forgot to add here.
I always have installled internally resisted coils on the flatheads so I didn't have to hang another ugly looking thing on the engine or firewall.
For those that dont know... the way i understand it. The resistor is used to step down the 12 volt current to the coil to 9 volts.
After discussion my setup to MSD they told me that their units require a full 12 volts to the coil. They did not say the MSD coil was required. So I installed a externally resisted coil without a resistor.
This was midway in my investigation and there still was no change in how the engine acted from this coil change but it may have added some problems.

 

im gonna save this thread in my favorites.. thanks for the info i have a feeling it might come in handy oneday.

 

Yes it does,
But at least i was able to drive it during this past summer.
The frustration would really be bad if it was a problem that prevented any of that.
Always something... in the co**** of taking the truck out this past week on test drives, i had second gear chip a tooth.
I know what I'll be doing when the snow flies.

 

A professional engine builder I know says, "The ONLY two used parts that should ALWAYS go into a newly rebuilt engine.....are a KNOWN GOOD used carburetor and ignition."

Pretty good advice, it's worked for me for 20 years.

He never said anything about voltage regulators, though. Thanks for sharing this. It never hurts to remind people to look at other systems besides the standard "must be the carb or the dizzy", & I'd bet that somebody on here will remember this thread when they have a problem of their own. Good work.

 

You may not want to run that coil for long . . . as having 12 volts to it may cause it to overheat and fail in the end. For the life of me, I can't see why the MSD would care about your coil - as long as the coil was functioning well and had good output. If your coil was meant to run with a resister, then I'd run it with one. Yes - you can always replace the coil with a new one, but you might just be spending money for nothing.

Let us know how it works out! I was thinking about running a front mount MSD on my blown motor . . . with a digital 7 ignition that enables me to set the timing curves as they relate to manifold va***e or pressure. When I get that setup running, I'll let you guys know how it works out!

Dale

 

i know you banged your head against the wall on this one......

grandpa always says, "If you don't have any problems, you don't learn anything." Somehow, when I'm ticked off at something on my roadster not going my way, I forget this!

Glad to hear ya got it!

 

so,what your saying is that your battery voltage was low and that caused the engine to missfire? which also means you never checked the voltage at the dizzy while it was running?
randy

 

Yes, These distributors and ignition boxes have all weathertight connections and no exposed termination. Not an excuse.
Naturally if I would have went directly to the problem this post would not have been written, Hindsight.
Its puzzled me that when i discussed this problem with MSD that was not an item that they considered either. It must not happen too often otherwise they would have listed it.
Just thought i'd share my reasoning behind the elimination that i went through, PJ

 

where was he when you posted your problems threads?

.....nothing like a good monday moring quarter backing...

i think he meant well, just came off a little brash.....

 

very good info, we've got a similar problem on our 51 conv. Guess I should check that while its nice today.

 

Bored and stroked is correct.I spoke with MSD tech. dept.this afternoon just to get my info correct since Mallory requires resisted coil voltage to pos. side of coil and full12v. to red wire to dist. Since I use both types of dist. according to the customers request I wanted to be sure. MSD said that their coil uses 12v but any other mfg. coil that is required to have a resistor should use it or it could cause premature coil failure. Simply hook up your coil with a resistor and then pick up the MSD needed 12v on the feed wire to the resistor side.You have your cake and eat both.