Pre-war (up to 1942) 1941 Flathead with Pertronix Ignition

[J. Russo]

I searched several posts on this forum related to conversion to Pertronix, but I would appreciate more input specifically related to Pertronix performance on the 1941 Flathead.

I have a 1941 Series 63 Sedan (6 volt, positive ground) that runs very well as is. What I am curious about is the following:

1. What would I gain in terms of improvements/performance with converting to Pertronix?
   Does it result in faster starting, better engine performance, etc.
2. I am aware of the suppression spark plug wires needed. I am using an OEM ignition coil. Do I need to switch to a different coil?
3. Are there any judging concerns I need to be aware of?
4. I have a working rebuilt radio with modern components. Any concerns there?

Thank you

Thank you

[Jeff Rosansky CLC #28373]

For what it's worth, I put a basic set in my 70. It MAY have started a little faster, but not much.
A few years ago I put the points back in because I was doing some troubshooting...... it wasn't the Petronix, but I never just never put it back in. Still running the points.

I dont know what a fancier set would get me, but I wouldn't make the effort to put a basic set in another car. In fact, when we woke our 55 up, I just stayed with points.

[TonyZappone #2624]

A friend of mine with a forty car collection installed Pertonix in my '41 60 Special, (since sold) my'47 convertible, and my '36 Pierce Arrow (dual points) 15 years ago.  This has been a revelation, starting is instant, power is better, we did not replace plug wires in any of them.   Yes, a special coil is needed, and another wire for that coil which we just hid beind the new coil.  Your Pertonix dealer will provide you with the right parts, just give them the distributor number.  No more points closing up, leaving me stranded, just fast starts and great performance.  Remember my cars have had this installed over 15 years.

[TJ Hopland]

Are you having starting issues?    If judging is a concern it kinda seems like you don't really have any options.  Pertronix has an extra wire between the dizzy and coil and you could end up wanting a different power feed to the coil. 

Any time 6v comes up my first thought is to head down to an industrial truck and tractor supply store for the fattest battery cables they stock like at least a 2/0 gauge.  That seems to cure many of the common 6v issue but they sure are not gonna look stock.   

[TonyZappone #2624]

I have used welding cable for battery cables on 6 volt cars.  Both my CCCA era cars are first prize junior and senior cars, and the CCCA tends to overlook minor items that help mechanical performance.   All my cars have electric pumps, if fuel is present, starting is instantaneous with Pertonix.  I find every aspect of engine performance is improved, starting, acceleration, etc.

[J. Russo]

Are you having starting issues?    If judging is a concern it kinda seems like you don't really have any options.  Pertronix has an extra wire between the dizzy and coil and you could end up wanting a different power feed to the coil. 

Any time 6v comes up my first thought is to head down to an industrial truck and tractor supply store for the fattest battery cables they stock like at least a 2/0 gauge.  That seems to cure many of the common 6v issue but they sure are not gonna look stock.   

I'm not really having starting issues other than the typical 6 volt slow turnover. The car runs great. I also have the appropriate battery cables installed. I'm simply collecting input from the great folks on this forum to decide if Pertronix is something I'd like to do in the near future. I appreciate any and all input.

[LaSalle5019]

Properly maintained points and condenser does the same thing a Pertronix system does....energizes and collapses the primary field in your coil. Lots of aircraft flying around using points and condenser due to their predictive reliability. I replace mine well BEFORE they fail. I've removed the Pertronix systems off of several cars I purchased and went back to points and condenser for one reason....if I do have a failure, I can be back on the road in 20 minutes. While I'm not saying that Pertronix is unreliable, I know of two people that have had theirs fail while touring. Heck, my modern Buick had it's electronic ignition recently fail for no reason and needed a tow. If you do buy one, I would buy a spare, just in case, so you don't get stranded.

[Jim Miller]

I've kept my '41 with points and condenser. For better starting I have two 6 volt Optima in parallel - 6 volts but lot of starting amps. And each spring I take emery paper to all my grounds and connections. 8 years and no issues.

[TonyZappone #2624]

I repeat.  15 years, three cars, no failures with Pertonix

[TJ Hopland]

My rule with points is if I really don't have to mess with them they can stay.  If I seemingly always have to mess with them and there is a more or less drop in electronic option I take it.  I got a flathead and tractor both from the 6v era that I don't even remember taking the cap off of that just work and work which is great because neither of them are common enough to have a direct fit electronic option.

Starting in the 90's when even small and industrial engines hadn't had points in 10+ years is when the quality of replacement points and condensers started getting a little hit and miss and its been a steady decline since then.  I think points were a great example of once the OE's didn't have to even do warranty support anymore they just didn't care about the quality so even if their name was still on the box they were often junk.

One engine recently I got the rig cheap because it didn't run. Found (among other issues) the plastic part of the arm had cracked.  No problem ordered another set.  Same thing happened after a couple hours, not a huge shock since they only cost like $10.  Got a $30 'genuine' set online and the arm didn't crack but what ever material they were made of or the plating only lasted a couple hours. 4th try I actually walked into the dealer (can't remember if it was CAT or Cummings) and ordered another set for $80! but they are still working.  I do have an electronic conversion on em so they are not having to switch the full load, they are just triggering the electronics.

[TJ Hopland]

I guess I got off track storytelling..   I was gonna say some sort of electronic conversion that runs off the points can be a good option because it takes the stress off the points so if you do manage to find a nice quality likely old stock set they should last a lifetime.  The classic MSD6 ignition box was one of my favorite options but those have got less reliable and more expensive these days.  You used to be able to buy kits too but over the last few years those seem to have gone out of production.

An advantage to the electronics triggering off the points other than the increased life of the points is since you are leaving the points in place if you set up the wiring with connectors and the electronics failed you can just plug the coil back to the points and make it home.

There were some of the kits that could do 6v but I think had to be neg ground so that was a limiting factor even years ago.  Today I would guess would guess if you are not 12v neg you are not gonna find anything ready made.

[tcom2027]

I'm not really having starting issues other than the typical 6 volt slow turnover.


Good morning John,

If you have at least 2/0 cables, with heavy duty ends swaged or crimped on and a good starting motor a group two commercial 780 amp hour battery will turn the 322s and 346s over just fine. It will start a lot easier as there is more current available for the coil, allowing it to produce a hotter spark. A group four 880 or 900 amp battery better if it will fit in your battery carrier.

I had a group four CAT battery in both of the '41s I have owned. My '41 coupe started just fine after sitting all night in twenty eight degree winter weather at Lake Tahoe.

As an aside, with working shutters and a working automatic heater it was comfortable as a modern car. 

tony

[z3skybolt]

Sometimes I wonder...

....if these starting issues are not more related to carburation than ignition?  I have owned two 1940 LaSalle. Both with the original 6 volt system. The first one, although perfectly maintained, was hard to start and almost impossible when hot. I was constantly running the battery down and having to jumpstart. A pair of Trojan batteries solved the problem of draining the single battery....but it did not crank any faster nor improve the starting. 

 The first LaSalle also required a backup electric pump. I had to use it to start the car, overcome frequent vapor lock and supplement the mechanical pump every few miles.

Now this discussion is not about fuel pumps, but I wanted to include the full picture.  Enter my current 1940 Lasalle purchased 4 years ago and driven nearly 9,000 miles.  It does not have an electric fuel pump, retains the original 6 volt system and starts INSTANTLY every time, regardless of the weather! Never once has vapor locked. Runs beautifully.

What is the difference between those two cars?  The carburetors! The first LaSalle had the original design 1940 carb. My current LaSalle has a 1946 carburetor. Carburetors were much improved during the WW-2 period.

Everything else is the same. Purely stock.  Most of you have newer Cadillac....but the principles are the
same.

For what it is worth.

Bob R.