Best 6v ignition

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Paul Bennett

Well-known member
I plan a sit-down w/Flathead City to engineer a replacement engine for my daily driver. I am not very knowledgeable about ignition systems and solicit your help as what to specify.

The 272 to 285ci engine will probably have a 4bbl and 4 1/8" Scat crank. I realize 12v could provide more ignition choices but I'm staying with 6v for now.

A Vertex Magneto may be best but $1300 is a bit more than I wish to spend. I hear tell of a 'converted GM dist', but googling turns up nothing. Some tell of trying a dozen dizzys, but I'd like to start and and end with the same one.

What say ye about distributors/ignition?
 
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Which style distributor are you planning to use; the early front mount(driven directly by the camshaft), or the later one that sits in front of the right cylinder head?
 
40 Deluxe said:
Which style distributor are you planning to use; the early front mount(driven directly by the camshaft), or the later one that sits in front of the right cylinder head?
Click to expand...

The 8BA distributor sits at front of the passenger side cylinder head.

Been reading stuff found on HAMB and learned the vacuum advanced have better mileage and city driving characteristics but are hard to tune. Modified Delco units with mechanical advance only (no vacuum) do have several advantages. So far users seem to modify/tune rather than buy new.
 
A Magneto is not a good thing to run on the street they have no advance built into them so they are at maximum advance all the time. Forget the 6 volts and convert to 12 volts.
Then you can use any modified Chevy V8 distributor whether a stock with points, an HEI or any after market distributor. I have used a Chevy MSD distibutor and box and also a Mallory 8BA dual point distributor coverted to a Pertronix module.
A good machinist can do the job for you it’s not too hard.
My 2 cents....
 
I agree about a magneto being impractical (and expensive) for a street cruiser. A points distributor doesn't care what voltage you are running. If you are going to run 6 volts (which I have found to be entirely satisfactory), stay away from electronic ignition setups. I personally am running mechanical advance only Mallory dual point distributors on both of my 8BA's and have absolutely no complaints. I have come to believe that vacuum advance is not as important on a flathead as on some other engines because of the lesser total advance required (22 vs 36 degrees).
 
PB,
The Chevy distributor converted to 8BA has a serious plus and that is....it is
fully tuneable without having to remove it from the motor. Mechanical weights and
springs are under the rotor and immediately accessible and the maximum advance
is adjustable as well....on distributors I build....by simply removing the cap and turning
an allen adjuster in or out.
Only your motor knows.. what curve and max adv it wants....over and above
a generic setup.
Charlie ny
 
You want to get the best mileage you need vacuum advance.
Tuning a distributor isn´t that difficult.
The degree of mechanical advance is limited by the slot so you can make it longer for more advance or in most cases using a later distributor you want to limit it for less to suit the flathead.
The combintion of the 2 springs 1 softer and 1 stiffer makes the curve non linear.
You choose 2 that is closest to your need then bend the tabs they are attached to for fine tuning.
I take the cheap accel units (which to me is lees bulky then a HEI) cut it down on a lathe and attach the gear from the original distributor.
Then you get a vacuum canister that is adjustable ( you stick an allen wrench into the vacuum pipe to adjust it) and you can tune it every way you want.
You can run electronic ignition on 6v but that comes with some issues...and basicly you don´t need it...not like we put massive amount of miles on the vehicles and can´t live with lifespan of points...the flateads have narroow plug gaps so no need for huge ignition voltages.
 
I drove cross country on one of Charlie's distributors with 6 volt. When I got a few bad condensers I went to a Pertronix and returned to the original distributor and have driven that cross country and back. This is on a stock motor. The chevy vacuum give you a bit more advance at idle and at cruising speed when you step on it it will retard it a bit due to the vacuum loss and prevent pinging. At least that is how I understand it.
 
I have found that the best distributor for my 35 avatar driver is the original helmet distributor, properly set up/timed, and using all good high quality components, including a Skip Haney rewound coil.

On a built-up 284ci, 3-5/16" bore, 4-1/8" stroke, 59a engine, I'm planning to run Harmon-Collins dual point, dual coil, or Lincoln dual point, dual coil converted from V12 to V8. These combinations will also use Skip Haney rewound coils.

I've never felt a need for a distributor converted to electronics, nor a 6 to 12 volt conversion
 
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Go on HAMB, look up Bubba. He does the Chevy conversions. If you want to stay with 6V, get a Pertronix 6V pos gnd unit and their 0.6 ohm coil.
 
Both of the combinations mentioned in my last post are 6V. Never felt the need for 12 volts, nor electronics on these distributors. Not something easily repaired on the side of the road in Kansas or Nebraska, where all you have as far as you can see are corn fields.
 
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Paul,
Since you are going to spend big money on having your engine professionally rebuilt, I would highly recommend that you convert to 12V. Be sure to discuss this with the rebuilder and make a list of the PRO's and CON's. 12V will prove to be the winner every time and will save you money with much better dependability and performance in the long run. The money your planning to spend on a Vertex magneto could better be spent on other components. Please rethink your plan about running a mag. Not recommended for 6V daily driver. Be sure to read ALL the pertinent info. here:
https://www.google.com/search?q=ver...rome..69i57.9538j0j4&sourceid=chrome&ie=UTF-8

If you want the "look" of a magneto, you can convert a magneto to 12V electronic ignition

I know there are lots of folks that disagree but you will never regret the conversion.

Oh, be sure to have your complete rotating assembly balanced.
 
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Agree on the 12 volt conversion.
Besides all the 12 volt goodies you can install there are all the Oooooohs! and Ahhhhhhs! you will get. :)
 
Running a Bubba mechanical advance Chevy Dizzy in my 8ba with a stock Merc Cam and EAB heads. Runs like a champ right out of the box. Also running a 94 carb that CharlieNY rebuilt and his work his excellent as well. If it were me I'd go with a modified Chevy dizzy from either of the 2 and convert to 12 volts. JMHO.
 
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