8BA ignition

[41LjH]

What distributor coil combination is working best for folks with a modified 8BA ?
I am very happy with the Mallory electronic setup on my truck but it is a little pricey. So I am considering a pertronix Ignitor for this build but I have heard good and bad about the loadmatic vacuum only distrubutor. I have a H&M 400Jr regrind and plan to use either three 94s or the 4160 Holley I have on hand.

thanks in advance for you opinions

[JSeery]

Why not use the Chevy setup?

[BUBBAS IGNITION]

Once you add a camshaft and multiple carbs you no longer have proper vacuum to control the loadamatic vacuum only distributor...
At this point you have a number of options ( all of them aftermarket)

[Bruce Lancaster]

Also, adding things to the Loadamatic is pretty much a waste of time. It makes sparks just fine if you know the little diddly things to check and can get decent points from NAPA. Its problems are all in the advance, even on a stocker, and really require its replacement.

[chap52]

I would say...let Bubba help you through this one.

[Deuce Man]

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Ditto on Bubba, his cut down chevy distributor was the best thing I ever did for my mildly worked merc flathead. Rich

[41LjH]

Thanks guys I will PM Bubba

[Ol' Ron]

Bubba will convert a GM dist to operate on centrifugal and vacuum advance, thus giving both power and economy when needed, the only aftermarket unit that can do this,s the MSD. However, that would have to be setup to operate a Flathead properly.
Just curious, Why did you select the 400jr cam?? This is an excellent cam for racing especially on a short track. However the reliably factor for a street engine is marginal.

[rick r]

I have been using an early 1980's 318 chryco electronic unit with the orange coloured ign module. About an hour with a small lathe to re work to fit an 8ba. E mail me at [email protected] if you want more info.

[flatheadmurre]

I usually take an mallory mech adv from a SBC (they are cheap used) and put it in the lathe.
A mech/vac like bubbas has some pros over the mech only, and having it readily tuned for your aplication saves you a few hours tinkering...

[Richard in Florida]

Originally Posted by 41LjH

What distributor coil combination is working best for folks with a modified 8BA?

If you have lathe access and experience you can make your own Chevy conversion -- either points (easiest) or magnetic trigger to fire an electronic ignition.

Here are my "Frankenstein" Big Cap Chevy distributor (parts of two different distributors grafted together) and my Crane ignition with HEI backup under my '53 dash. Both have been flawless for about three years now.

[scooder]

Richard,
Your Frankenstein distributor, could you elaborate on why it's two crafted together please? Could you not just machine a regular che7y HEI and use that?
Thanks,
Martin.

[Richard in Florida]

Originally Posted by scooder

Richard,
Your Frankenstein distributor, could you elaborate on why it's two grafted together please? Could you not just machine a regular chevy HEI and use that?

I grafted most of the stem of another Chevy distributor to part of the HEI stem because the HEI stem alone is too short. The distributor body had to be raised about 0.75" to clear everything so it could sit all the way down and not hit the water elbow.

The shaft, however, with a little trickery, was long enough and didn't need lengthening.

I have lots of pictures if you're interested in trying it.

[Deuce Man]

I cut down a chevy points distributor for my mild 50 merc motor. It ran pretty good, but without being able to recurve it to whatever Bubba does, it never was as good as the Bubba's distributor. Rich

[Richard in Florida]

Originally Posted by Deuce Man

I cut down a chevy points distributor for my mild 50 merc motor. It ran pretty good, but without being able to recurve the it to whatever Bubba does, it never was as good as the Bubba's distributor. Rich

What did you try and what happened? Do you have a good "straight" timing light and an accurate TDC mark?

Do you have access to a distributor machine?

The secret is in the springs and in setting the advance RANGE. Other important factors are gear alignment and shaft end play.

Happy to help if you have questions.

[scooder]

Thank you for your explanation Richard, didn't know the length difference on the HEI.
Deuce man,
As Richard said, curve wise, it's springs and advance range. If useing a recurve kit, lightest springs are normally the ones, lighter would be nice. Normally make my own advance stop bush. The advance, in my opinion needs to be tailored to the car spec, engine spec and intended use. If your gonna do it, do it right.
Martin.

[Richard in Florida]

Thank you for your explanation Richard, didn't know the length difference on the HEI.

Both stems are about the same length but the HEI body is MUCH wider and therefore must be higher for clearance.

Deuce man, if using a recurve kit, lightest springs are normally the ones, lighter would be nice.

There's nothing "holy" about the springs in recurve kits. I made my own springs from springs stock of all shapes and sizes. Just takes patience and experimentation.

Normally make my own advance stop bush.

Don't know if I was the first in recorded history (you never are here!) but I've been using a setscrew to adjust the range instead of a bushing. Now all of Bubba's units incorporate my idea. Fabulous for fine tuning

The advance, in my opinion needs to be tailored to the car spec, engine spec and intended use. If your gonna do it, do it right.
Martin.

Yes, technically you're right. But in Real Life good old trial and error sweetened with a little Kentucky windage saves buying a lot of test gear and doing a lot of math.

Oh, I did make my own distributor machine from some scrap wood, some hardware odds and ends, and a sewing machine motor. Works great!

[Ol' Ron]

You should see his road machine, checks advance, AF, vacuum,and records this on tape for further use. Nice guy to have around.

[Richard in Florida]

Originally Posted by Ol' Ron

You should see his road machine, checks advance, AF, vacuum,and records this on tape for further use.

Ol' Ron is referring to my "Road Rig," a diagnostic package I dreamed up to monitor manifold vacuum, engine RPM, A/F ratio, and actual real-time advance... and it records all this on video tape along with my running field commentary. It ain't nuclear physics but it's a terrific diagnostic tool.

[scooder]

You got more test gear than I have Richard, love the dizzy machine and the road rig.
I think you can safely claim the advance stop screw as your baby too.
If you were a cartoon character you'd have a light bulb above your head constantly.
Really admire your "Git er done" mentality.
Martin.

[Richard in Florida]

I think you can safely claim the advance stop screw as your baby too.

Well, I never heard of it before I dreamed it up, but there's always someone who says, "Aw, we used to do that back in '49." Same thing happened when I dreamed up using little balls of aluminum foil instead of clay for checking clearances under the heads. I called them "AlumaPeas." Sure enough... "Aw, we used to do that back in '49."

If you were a cartoon character you'd have a light bulb above your head constantly.

I'm always looking for a better way to do something or to build a tool I can't afford or that doesn't exist. Hey, that's at LEAST half the fun!

[40grit]

Good to see you here Richard!

If any of the readers here are wondering about the Chevy conversion, I drove the 36 to Nashville a couple of months ago. It has a Chevy Points distributor with 3.25 9 inch rear end and S-10 5 speed.

Monteagle Mountain in I-24 is a 6% grade for 4 miles without any break. I topped the mountain at 65 mph and never came out of 5 gear. Temp was 195 degrees but it was still pretty cool weather at about 76 degrees. With the overdrive and the 3:25 rear, I probably have about a 2:50 to 2:75 final ratio.

The point is good ignition and proper timing is the best gift you can give a flathead. No way would I give up the Chevy conversion on my motor.

John Long

[Ol' Ron]

I saw My first Chevy conversion back in the 60's and made my first one soon after. However I didn't use the vacuum advance untill I built a 296 for Ron horrell. He said you need this for cruise when the fuel charge is lean and needs more advance. Boy did I feel dumb. Stupid is, what stupid dose.